7,899 Matching Annotations
  1. Nov 2022
    1. Reviewer #1 (Public Review):

      Tomanek and Guet describe the results of an evolution experiment where they allowed the bacterium E. coli to adapt to various concentrations of galactose as an additional carbon source. These conditions impose different degrees of demand for the galK enzyme, whose expression level depends on the promoter sequence and on the number of copies of the galK locus. Given that the initial promoter is random and weak, both amplifications of the locus and mutations in the promoter are expected to be adaptive. The experimental strains of E. coli were equipped with a fluorescent reporter system designed to discriminate between these two types of mutations. Furthermore, two strains, IS+ and IS-, were engineered with high and low rates of duplication around the galK locus, respectively. The main result is that at higher concentrations of galactose, where the demand for galK is high, E. coli adapts by acquiring combinations of both types of adaptive mutations, amplifications, and promoter mutations. In contrast, at low concentrations of galactose, where the demand for galK is low but not zero, E. coli appear to adapt by acquiring either an amplification or a promoter mutation but not their combinations. The observation of apparent interference between the acquisition of these two types of mutations is interesting and novel. The authors provide an intuitive explanation for it: when one mutation is sufficient to achieve the optimal expression of the gene, the mutation that is acquired first makes the other mutation obsolete, i.e., there is negative epistasis (possibly even sign epistasis) between these mutations, in the sense that the second mutation is much less adaptive (or possibly even deleterious) in the presence of the first one, in the low-demand environment. The authors discuss the possible implications of this finding for our understanding of molecular evolution and propose a new Amplification Hindrance hypothesis. This hypothesis states that, since amplifications occur at much higher rates than individual point mutations, they can slow down or even prevent sequence divergence. The amplification hindrance hypothesis stands in contrast to the Innovation-Amplification-Divergence hypothesis which is currently the default paradigm and states that amplifications generally accelerate sequence divergence.

      STRENGTHS:

      The authors designed a powerful reporter system that allows them to monitor the evolutionary dynamics of amplifications and promoter mutations. They ask an important question: how do early evolutionary dynamics of adaptation to environments with different demands for gene expression look like? The phenotypic data they present looks very interesting and shows the existence of interference between amplifications and point mutations in low-demand but not in high-demand conditions. The Amplification Hindrance hypothesis is a novel and useful intellectual contribution to the field.

      WEAKNESSES:

      In my opinion, the main weakness of the paper is that, while the interference between amplifications and point mutations in the low-demand condition clearly happens (most convincingly shown in Figure 5), its causes remain unclear. In particular, the authors claim that this interference is caused by negative epistasis, but the possibility of clonal interference without epistasis has not been decisively ruled out. The authors mention clonal interference tangentially in the Discussion, but they do not seriously address this alternative explanation. Yet, understanding the cause of this phenomenon is important because clonal interference and negative epistasis have different implications for long-term evolution.

      The authors' main hypothesis is that, in the low-demand conditions, expression-increasing point mutations in the promoter provide much lower fitness benefits (or even incur fitness costs) in strains with galK amplifications compared to the ancestral strain without amplifications. The most direct way to test this hypothesis would be to measure the fitness effects of a point mutation in genetic backgrounds with and without amplifications in conditions with low and high demand for galK. This decisive experiment has unfortunately not been done. Instead, the authors construct an indirect argument, whose essence is as follows.

      They show that, over the course of the experiment in the low-demand environment, the IS+ populations have acquired fewer point mutations than IS- populations (Figure 5). In addition, the phenotypic data in Figures 2 and 4 demonstrate that IS+ mutations in the low-demand environment contain three phenotypic classes of cells: ancestral, YFP+ and YFP+CFP+. The YFP+ clones are shown to have only one or two promoter mutations. The YFP+CFP+ cells must have duplications, and it is likely (although not quite certain, see below) that they do not have any promoter mutations. These data demonstrate quite convincingly that, whenever adaptation by duplications is possible, the rate at which point mutations segregate and accumulate declines. These data are consistent with the authors' hypothesis based on negative epistasis. However, they also seem to be consistent with the idea that amplifications and point mutations exhibit clonal interference without negative epistasis.

      It may be possible to construct an argument against this alternative hypothesis based on the comparison between different environments, but such an argument would have to take into account the fact that clonal interference depends not only on the rates of mutations (which are presumably the same in all environments) but also on their fitness effects which vary across the environment. Another possibility to argue against clonal interference might be by carrying out simulations, although this approach also seems challenging without knowing some key population genetic parameters. The most direct way to resolve this ambiguity would be to demonstrate negative epistasis as discussed above.

      Another, less critical but still important, issue mentioned above concerns the authors' claim that the YFP+CFP+ cells have only duplications but no promoter mutations (e.g., LL. 276-277). This is certainly consistent with intuition since these cells have an increased level of both YFP and CFP relative to the ancestor. However, as far as I can tell, there is no evidence to support this claim directly. My understanding is that the authors base this claim on the fact that YFP+CFP+ cells form a cluster of points on the YFP vs CFP plots that is distinct from the cluster of "mixed" cells, which are shown to have both an amplification and a promoter point mutation (Figure 3). But it is still logically possible that the YFP+CFP+ cells have an amplification and a promoter mutation other than the one found in the "mixed" cells (e.g., weaker). The most direct way to show that YFP+CFP+ cells have no promoter mutations would be to sequence a few of them. Another possibility would be to calibrate the YFP/CFP fluorescence measurements against galK copy number.

    1. Reviewer #1 (Public Review):

      Dectin-1 is a known C-type lectin receptor that has a role in recognizing pathogen glycans, particularly beta-glucan. Haji et al. present evidence that Dectin-1 also has an endogenous ligand, another C-type lectin that is enriched on platelets called CLEC-2. Using a Dectin-1 reporter line, they identify human platelets as a source for the ligand, raising a panel of mAbs to human platelets and identify one (6D11) that prevents signalling and use this to identify CLEC2 as the Dectin-1 receptor by immunopurification. The authors go on to further characterise this interaction by showing that it occurs between the human but not mouse orthologues, showing that it is the stalk region of human Dectin-1 that contains the ligand which consists of sialylated core 1 O-linked glycans displayed on Thr 105 and adjacent amino acids. Finally, the authors over-express human Dectin-1 in mice within the context of a null background for another CLEC-2 ligand (podoplanin) and show that this rescues embryonic lethality. They show that Dectin-1-dependent CLEC-2 signalling is not sufficient to induce platelet aggregation but can rescue perinatal lethality in podoplanin-deficient mice.

      There is a large amount of work in this manuscript and the experiments are well controlled and the results unequivocal and usually verified by several independent techniques. The paper is very well-written making the volume of data accessible. There is novelty here in that this unusually finds that 2 C-type lectin receptors directly interact and the biochemical characterisation of the glycan binding determinants is very well performed. While the authors show that the interaction occurs between the human but not mice orthologues (because mouse Dectin-1 lacks the critical EDxxT motif that is necessary for displaying the o-linked glycan in the correct context) they were able to investigate the functional role of the interaction by generating mice that overexpressed human Dectin-1 in a podoplanin-deficient background. Normally, podoplanin-deficient mice die at birth due to defects in lymphatic vessel development, but this lethality is rescued by overexpression of human Dectin-1. This xeno-overexpression data can be difficult to interpret but suggests that while human Dectin-1 signalling to mouse platelet CLEC-2 is insufficient to drive platelet activation and thrombus formation, it is sufficient to rescue some aspects of platelet function involved in lymph vessel development. They conclude that human Dectin-1 (which is broadly expressed on different tissues) provides a basal level of tonic signalling through platelet-expressed CLEC-2 to establish platelet signalling thresholds.

      I thought the manuscript was comprehensive in its approach, well written, and that the experimental data supported the conclusions.

    1. Reviewer #1 (Public Review):

      The authors tackle an interesting problem: how do ant colonies regulate foraging in response to their collective hunger? In previous work, the authors related the colony's response to individual ants sensing their own food levels and its temporal dynamics. Looking more carefully at the spatial dynamics of ants, the authors now find that foragers tend to move toward the depth of the nest when their food load is high and toward the nest exit when it is low. This is an elegant and computationally inexpensive set of rules that explains the spatiotemporal dynamics of the system.

      Overall, the paper is written clearly, the methods are sound, and I agree with the interpretation of the results.

      I do have a few comments and suggestions:

      1) How exactly are the inward outward directions defined? Is it simply, away, or towards the entrance? It is not clear from the text, and since this system is not symmetric (cubic with entrance at one of the corners) the authors should clarify.

      2) To analyze the biased random walk analysis of the ants, the authors "coarse-grained" the steps as being "inwards" "outwards" and "stay". It's not clear how this level of granulation is justified. Since the authors have access to the actual trajectories and all trophallaxis events, why not just calculate the actual turning angles between consecutive steps the ants take? This would give an actual assessment of both the bias and the noise imposed on the random walks, which the authors could then use directly in their models.

      3) It would be important to better connect the author's previous mechanism (relating the colony's response to individual ants sensing their own food levels and its temporal dynamics) to the new mechanism (spatial-temporal dynamics). Are they mutually exclusive? It would be useful to elaborate on this in the Discussion.

      4) It would be useful to add a few supplementary movies from the experiments, showing ants moving toward the entrance with low food loads, and moving away from the entrance with high food loads.

    1. Reviewer #1 (Public Review):

      This paper addresses an important issue of how humans select foot placement when running on uneven terrain. The authors examine empirical and model-based data to determine whether runners specifically opt for more level locations on such surfaces. The manuscript suggests potential strategies of how humans mitigate fore-aft impulses during foot contact so as to maintain stability in response to changes in terrain.

      Overall, the manuscript provides additional insight into lower-limb mechanics of runners on natural surfaces. The model-based analysis of lower limb compliance is especially useful in the context of stability and understanding human motor control. In addition, participant foot placement analysis using empirical and statistical models is very compelling and provides insight into how much planning occurs during running on uneven terrain. However, there are a few concerns of note:

      - A central motivation of the study appears to be that past research did not incorporate height and slope variations when studying gait on uneven terrain. Although some of the past work cited by the authors does focus on step-like terrain, the (Voloshina, Ferris 2015) study had both height and slope variations. In that particular study, the terrain consisted of blocks that were smaller than the dimensions of the average human foot. This means that, during each foot-flat phase, the foot had to span at least two blocks of different heights, placing it at a slope in the fore-aft direction. Similarly, the columns of that terrain layout provided slope variations in the medio-lateral direction. Referring to this surface as "step-like" is inaccurate and potentially misleading. Considering that the terrains in the present study and the study from 2015 likely cause very similar types of perturbations to the runner, the motivation behind the current study is not strongly validated. The authors should consider re-evaluating their results in the context of past studies.

      - A primary outcome of the study is the analysis of empirical and model-based fore-aft impulses experienced by runners during foot contact. The authors suggest that this measure is related to stability but do not provide extensive explanations. It would be helpful to include additional background information on how impulse analyses have been used previously and why they are particularly fitting in this context.

      - The study evaluates participants running back and forth on a 24m track for up to 10 minutes. This means that participants had to perform many turns during each trial. The authors present metabolic energy expenditure data but do not address how these data may be skewed due to the large instances of directional changes. Measuring metabolic data during such tasks is generally noise-prone, potentially leading to an inaccurate representation of energy expenditure. Considering that this is a comparative study and participants had to perform such turns for each terrain trial, this issue could be minor. However, the authors are encouraged to provide more detail on experimental protocol. Addressing whether or not participants stepped off the terrain to switch directions and providing insight into how this experimental approach could potentially affect outcomes could be particularly helpful.

    1. Reviewer #1 (Public Review):

      This is a fascinating paper that takes up an important question with a creative and new approach. We have a few suggestions that we hope are constructive for the authors.

      1. One nagging concern is that the category structure in the CNN reflects the category structure baked into color space. Several groups (e.g. Regier, Zaslavsky, et al) have argued that color category structure emerges and evolves from the structure of the color space itself. Other groups have argued that the color category structure recovered with, say, the Munsell space may partially be attributed to variation in saturation across the space (Witzel). How can one show that these properties of the space are not the root cause of the structure recovered by the CNN, independent of the role of the CNN in object recognition?

      2. In Figure 1, it could be useful to illustrate the central observation by showing a single example, as in Figure 1 B, C, where the trained color is not in the center of the color category. In other words, if the category structure is immune to the training set, then it should be possible to set up a very unlikely set of training stimuli (ones that are as far away from the center of the color category while still being categorized most of the time as the color category). This is related to what is in E, but is distinctive for two reasons: first, it is a post hoc test of the hypothesis recovered in the data-driven way by E; and second, it would provide an illustration of the key observation, that the category boundaries do not correspond to the median distance between training colors. Figure 5 begins to show something of this sort of a test, but it is bound up with the other control related to shape. Similarly, if the claim is that there are six (or seven?) color categories, regardless of the number of colors used to train the data, it would be helpful to show the result of one iteration of the training that uses say 4 colors for training and another iteration of the training that uses say 9 colors for training. The text asserts that Figure 2 reflects training on a range of color categories (from 4 to 9) but doesn't break them out. This is an issue because the average across these iterations could simply be heavily biased by training on one specific number of categories (e.g. the number used in Figure 1). These considerations also prompt the query: how did you pick 4 and 9 as the limits for the tests? Why not 2 and 20? (the largest range of basic color categories that could plausibly be recovered in the set of all languages)?

      3. Regarding the transition points in Figure 2A, indicated by red dots: how strong (transition count) and reliable (consistent across iterations) are these points? The one between red and orange seems especially willfully placed.

      4. Figure 2E and Figure 5B are useful tests of the extent to which the categorical structure recovered by the CNNs shifts with the colors used to train the classifier, and it certainly looks like there is some invariance in category boundaries with respect to the specific colors uses to train the classifier, an important and interesting result. But these analyses do not actually address the claim implied by the analyses: that the performance of the CNN matches human performance. The color categories recovered with the CNN are not perfectly invariant, as the authors point out. The analyses presented in the paper (e.g. Figure 2E) tests whether there is as much shift in the boundaries as there is stasis, but that's not quite the test if the goal is to link the categorical behavior of the CNN with human behavior. To evaluate the results, it would be helpful to know what would be expected based on human performance.

      5. The paper takes up a test of color categorization invariant to luminance. There are arguments in the literature that hue and luminance cannot be decoupled-that luminance is essential to how color is encoded and to color categorization. Some discussion of this might help the reader who has followed this literature. Related, the argument that "neighboring colors in HSV will be neighboring colors in the RGB space" is not persuasive. Surely this is true of any color space?

      6. The paper would benefit from an analysis and discussion of the images used to originally train the CNN. Presumably, there are a large number of images that depict man-made artificially coloured objects. To what extent do the present results reflect statistical patterns in the way the images were created, and/or the colors of the things depicted? How do results on color categorization that derive from images (e.g. trained with neural networks, as in Rosenthal et al and presently) differ (or not) from results that derive from natural scenes (as in Yendrikhovskij?).

      7. It could be quite instructive to analyze what's going on in the errors in the output of the classifiers, as e.g. in Figure 1E. There are some interesting effects at the crossover points, where the two green categories seem to split and swap, the cyan band (hue % 20) emerges between orange and green, and the pink/purple boundary seems to have a large number of green/blue results. What is happening here?

      8. The second experiment using an evolutionary algorithm to test the location of the color boundaries is potentially valuable, but it is weakened because it pre-determines the number of categories. It would be more powerful if the experiment could recover both the number and location of the categories based on the "categorization principle" (colors within a category are harder to tell apart than colors across a color category boundary). This should be possible by a sensible sampling of the parameter space, even in a very large parameter space.

      9. Finally, the paper sets itself up as taking "a different approach by evaluating whether color categorization could be a side effect of learning object recognition", as distinct from the approach of studying "communicative concepts". But these approaches are intimately related. The central observation in Gibson et al. is not the discovery of warm-vs-cool categories (these as the most basic color categories have been known for centuries), but rather the relationship of these categories to the color statistics of objects-those parts of the scene that we care about enough to label. This idea, that color categories reflect the uses to which we put our color-vision system, is extended in Rosenthal et al., where the structure of color space itself is understood in terms of categorizing objects versus backgrounds (u') and the most basic object categorization distinction, animate versus inanimate (v'). The introduction argues, rightly in our view, that "A link between color categories and objects would be able to bridge the discrepancy between models that rely on communicative concepts to incorporate the varying usefulness of color, on the one hand, and the experimental findings laid out in this paragraph on the other". This is precisely the link forged by the observation that the warm-cool category distinction in color naming correlates with object-color statistics (Gibson, 2017; see also Rosenthal et al., 2018). The argument in Gibson and Rosenthal is that color categorization structure emerges because of the color statistics of the world, specifically the color statistics of the parts of the world that we label as objects, which is the same approach adopted by the present work. The use of CNNs is a clever and powerful test of the success of this approach.

    1. Reviewer #1 (Public Review):

      This paper uses 2 cohorts from the UK and links a) risk factors associated with low antibody levels after vaccination and b) risk factors for infection. The paper makes the important point that following the third vaccination, risk factors associated with low antibody response after the first vaccination, are less likely to lead to sub-protective levels. This highlights the importance of obtaining a booster shot. Though it is not a primary finding of the paper, the observed discordance between self-reported infection and anti-nucleocapsid positivity is an important finding. While these findings are potentially useful, the presentation of the data is somewhat unfocused, and the message is presented in a diffuse fashion. Moreover, certain key components of the analysis such as the assay threshold and timing of samples after the 2nd vaccine are a bit confusing and require clarification. The use of univariate analyses can be misleading. Finally, the relevance of the findings relative to our current stage of the pandemic with multiple new VOCs requires a clearer explication.

    1. Reviewer #1 (Public Review):

      The core conclusions in this manuscript are well supported. First, the genomic data clear support a recent origin of the Baltic and Arctic ecotypes from an Atlantic-like ancestor, without major bottlenecks and with gene exchange at least on the one sampled sympatric location but probably also more widely. The genome scans strongly suggest the involvement of multiple loci in divergence. This is supported by the quantitative trait locus analysis but this support is relatively weak because the number of markers used was small and markers were rather unevenly distributed on the genetic map, leaving little power to detect QTL in some areas. An analysis of the power of the QTL analysis is lacking and there might also be an issue about whether the measured trait truly captures rhythmicity.

      The presence of segregating variants across all sampled populations for the loci that appear to underlie local adaptation, plus the absence of strong sweep signatures, is good evidence that adaptation to the Baltic environment was based on standing genetic variation. This is supported by the known presence of local adaptation to tidal regimes within the Atlantic ecotype, providing a mechanism for the maintenance of standing variation. Clustering of putatively adaptive loci in one region of chromosome 1 seems clear, although it is not formally compared to a random distribution.

      The authors make an interesting point that it is only when many genes are involved that Gene Ontology enrichment is expected to be informative. Here, they also had clear a priori expectations which are neatly fulfilled, further suggesting that differentiated loci are good candidates for a role in adaptation.

      The broader context provided for the analysis of the fascinating marine midge system is brief and could usefully be expanded. It should make clear that, despite some focus on major gene effects that can be assigned to individual loci, there is widespread evidence for polygenic adaptation. Even where structural variants are known to have major effects, many other regions of the genome typically contribute to local adaptation. It would also be helpful to refer to theoretical expectations regarding distributions of effect sizes and clustering of locally-adaptive loci, with or without gene flow.

    1. Reviewer #1 (Public Review):

      The authors define regulatory networks across 77 tissue contexts using software they have previously published (PECA2, Duren et al. 2020). Each regulatory network is a set of nodes (transcription factors (TF), target genes (TG), and regulatory elements (RE)) and edges (regulatory scores connecting the nodes). For each context, the authors define context-specific REs, as those that do not overlap REs from any of the other 76 contexts, and context-specific regulatory networks as the collection of TFs, TGs, and REs connected to at least one context-specific RE. This approach essentially creates annotations that are aggregated across genes, elements, and specific contexts. For each tissue, the authors use linkage disequilibrium score regression (LDSC) to calculate enrichment for complex trait heritability within the set of all REs from the corresponding context-specific regulatory network. Heritability enrichments in context-specific regulatory network REs are compared with heritability enrichments in regions defined using other approaches.

    1. Reviewer #1 (Public Review):

      Yuan et al. propose that the magnesium transporter unextended (uex) controls Drosophila sleep via Mg2+ efflux, Ca2+-dependent CREB signaling, and a CNK-ERK pathway. UEX protein levels display daily oscillations in fly heads, whereas UEX-depleted flies show long sleep with low levels of Ca2+ and synaptic plasticity. Transgenic expression of wild-type UEX or the mammalian uex homolog CNNM1 possibly rescues the uex mutant sleep, supporting their evolutionary conservation. UEX forms a protein complex with the ERK signaling suppressor CNK, and UEX depletion appears to de-repress ERK activation. As expected, pan-neuronal CNK depletion phenocopies uex mutant sleep. Taken together, the authors suggest a novel mechanism whereby magnesium shapes animal sleep through the specific MAPK pathway. Overall, the authors reported quite a few exciting phenotypes in UEX-depleted flies using a range of analyses (e.g., behaviors, gene expression, Mg2+/neural imaging, and biochemistry). However, evidence for their causal link to sleep regulation is missing, and some key conclusions remain justified by more rigorous analyses. It is noteworthy that Wu et al. have previously demonstrated the Mg2+ efflux transporter activity of UEX and mapped its memory-enhancing function to a specific group of adult neurons in the fly brain (https://pubmed.ncbi.nlm.nih.gov/33242000/). Given the intimate interactions between sleep and memory, these findings may have broad implications in sleep-relevant physiology and disorders. However, a number of important control studies and statistical assessments are not included, but are necessary to conclusively interpret the data.

    1. Reviewer #1 (Public Review):

      Modified rabies viral vectors allow high throughput mapping of neuronal circuits with cell type specificity. However, lack of standardization in this field limits extrapolation of useful information, beyond the identity of anatomically connected regions, such as differential input densities and connectivity motifs. in this manuscript, Tran-Van-Minh et al., attempt to develop a statistical approach which will allow consolidation of new, as well as previously-acquired datasets, to yield biologically significant insights into the logic underlying rabies vectors' expansion from single starter cells.

      This question the authors address is of high importance and the presentation of this manuscript is timely, as rabies tracing experiments increase at an exponential rate. The authors provide a largely complete description of the main pitfalls and caveats in current analysis approaches and common misconceptions in the interpretation of results. In addition, they correctly diagnose the potential of this methodology to extract pertinent information from such experiments and provide the reader with useful tips on how to better design, analyze and interpret them.

      While such a paper is undoubtedly called for, and has the potential to substantially improve circuit mapping experiments, with little cost to the experimenter, there are a few critical flaws in their premises, which will limit a widespread adoption of their analysis approach. While the authors discuss caveats in design and interpretation of results, they do not implement these suggestions into their own experiments, such as the need for accurate estimation of starter cells and automated cell counting which is not biased by strong signal coming from dendritic arbors/axons in densely-labeled regions. While the authors claim that the reduction in residuals and relative conformity across experiments following log-transformation of n(i) and n(s) shows that their approach is robust, the large degree of variability across experiments, the datasets of some are biologically implausible, showing a decrease in n(i) as a function of n(s), suggests that this transformation disposes of useful information, which might help detect anomalies in data acquisition. The fact that the most rigorously-acquired dataset which was presented by the Allen Institute (BRAIN Initiative Cell Census Network, Nature, 2021) is the only one which, does not comply with the transformation, attests further to this caveat. This is probably the reason why the estimated number of individual neurons retrogradely labeled by a single starter cell (~1400) is more than an order of magnitude higher than any previously-published estimation, including those which include tracing from single-cell, and is highly unrealistic.

      In addition, the model selected by the authors to fit the various datasets does not take into proper account saturation of n(i), as all proposed functions are growing functions. Here, the most suitable model which should be used to describe the nature of RV expansion is a cumulative distribution function, while the rest are either private cases (e.g. linear fit given low n(s) or zero divergence) or are biologically unrealistic (e.g. exponential fit). Again here, the only dataset which appears to fit this function the best comes from the BRAIN Initiative Cell Census Network (Nature, 2021).

      In conclusion, while such work is called for and has the potential of becoming a staple in the connectivity toolbox, many of the premises presented here will need to be significantly adjusted, before the approach could be put into widespread use.

    1. Reviewer #1 (Public Review):

      The manuscript by Chen and colleagues contains a number of important findings. First, they showed with careful imaging, cell cycle characterization, and models that replisomes of fast-growing E. coli form factories and super factories (factories involving cousin replisomes), they estimated that factories split after the replication of 1/3 of the chromosome. Second, they used a replication fork block to monitor the interdependence of replisomes of factories. Third, they show that orphaned replisomes replicate slowly and frequently require a repair process to complete the replication cycle. This is the first characterization of an advantage of replicating bacterial genomes in a factory rather than as independent replisomes. This is an important discovery that simultaneously confirms the existence of DNA factories, a much-debated topic, and reveals one of their functions. The existence and characterization of factories were mostly addressed through imaging methods; here the combination of imaging with molecular genomics assays is a real asset for the manuscript.

    1. Reviewer #1 (Public Review):

      In this study, the authors investigate multi-attribute economic decisions in humans. More specifically, they investigate the impact of adding a decoy option to a binary choice, the effect of which has been debated in the previous literature with recent studies finding effects in different directions. By re-analyzing large datasets from some of these studies and by applying computational modeling to the data, the authors propose that a subjective encoding rule comparing attributes separately, and not computed as one multiplicative value, explains participants' behavior on different levels of granularity. Context effects were well captured by a selective integration model. The work has many positive features, including praising open science, the analysis of the potential confounds of previously used designs, and both quantitative and qualitative comparisons of several well-justified models.

    1. Reviewer #1 (Public Review):

      This manuscript provides the first cellular analysis of how neuronal activity in axons (in this case the optic nerve) regulates the diameter of nearby blood vessels and hence the energy supply to neuronal axons and their associated cells. This is an important subject because, in a variety of neurological disorders, there is damage to the white matter that may result from a lack of sufficient energy supply, and this paper will stimulate work on this important subject.

      Axonal spiking is suggested to release glutamate which activates NMDA receptors on myelin-making oligodendrocytes wrapped around the axons: the oligodendrocytes - either directly or indirectly via astrocytes - then generate prostaglandin E2 which relaxes pericytes on capillaries, thus decreasing the resistance of the vascular bed and (presumably) increasing blood flow in the nerve.

      Strengths of the paper

      The paper identifies some important characteristics of axon-vascular coupling, notably its slow temporal development and long-lasting nature, the involvement of PgE2 in an oxygen-dependent manner, and a role for NMDARs. Rigorous criteria (constriction and dilation of capillaries by pharmacological agents) are used to select functioning pericytes for analysis.

      Weaknesses of the paper

      The study focuses exclusively on pericytes. It would have been interesting to assess whether arteriolar SMCs also contribute to regulating blood flow.

      The slow (~10 minutes) time scale of the responses seen is remarkable when compared to grey matter neurovascular coupling which occurs in seconds. The authors suggest that this reflects movement of messengers along the nerve, but the action potential moves so rapidly down the nerve that it will activate the release of vasodilators essentially at the same time everywhere along the nerve, and there will be no concentration (or voltage) gradient to drive such a movement of messengers (unless there is a spatially localized unique site in the vascular bed where propagating responses are generated). Thus it remains unclear why the responses are so slow.

      The activity-evoked dilation is thought to reflect PgE2 release at what is probably a physiological O2 concentration, but not at the hyperoxic 95% O2 used in most of the experiments. The involvement of NMDA receptors is apparently only shown (using OL-specific receptor subunit deletion) at the unphysiological high O2 level. This raises two questions: are NMDA receptors also involved in the response at low O2 (as schematized in Fig 6), and what is the messenger downstream of NMDARs at high O2 (NO would be an obvious candidate, previously shown to contribute to NVC in the grey matter).

    1. Reviewer #1 (Public Review):

      The goal of this work is to study whether sleep and wake regulate cerebellar structural plasticity. Scanning electron microscopy and 3D reconstruction were used to characterize structural changes in spines and synapses in the mouse cerebellar cortex. The net number and size of synapses did not change between sleep and wake. However, the number of small portion of spines ("naked" spines without synapses) increased during sleep, and the number of branched spines (contains more than one synapse) increased during wake.<br /> The methodological approach (scanning electron microscopy) is laborious but adequate. However, it cannot follow the same synapses longitudinally, and live imaging, even only in superficial regions, is an ideal approach to achieve the goals.

      The results did not find changes in the total number of spines or synapses during sleep and wake. Structural changes were found in small number of spines lacking a synapse. Whether these changes are functionally important is unclear. The results support circuit-specific, rather than global, effect of sleep on synaptic plasticity.

      The role of sleep range from cellular maintenance to memory consolidation. Multiple evidence suggests that sleep regulates synaptic plasticity. Although this work did not attempt to understand the functional role of sleep in regulating learning and memory, it discovered that sleep promotes synaptic pruning in specific circuits of the cerebellum. Future similar anatomical studies in additional brain regions, including excitatory and inhibitory circuits, combine with physiological and behavioral assays are expected to provide insights to the role of sleep in regulating synaptic plasticity, learning and memory.

    1. Reviewer #1 (Public Review):

      Zebrafish have become a well-established model organism for studies of damage and repair in hair cell sensory organs due to organ accessibility and robust mechanisms for repair and regeneration. While lateral line organs in zebrafish are widely used to study hair cell physiology, zebrafish also contain hair cell organs in their inner ears that have the potential to be more comparable to mammalian counterparts. Using single-cell RNA seq in embryonic through adult stages, this study found that hair cells and supporting cells of the zebrafish inner ear are distinct from those of the lateral line. Additionally, they identified distinct cellular subtypes within the maculae and cristae of the ear.

      This work provides some novel findings, including identifying distinct markers in the macula and crista hair cells and supporting cells as well as detecting a domain in the zebrafish utricle that coincides with features of the striolar region in mouse utricle. However, while much of the focus of in situ expression analysis was the spatial separation of calcium-binding proteins capb1b and capb2b in the maculae, it was not clear how Capb1 & 2 expression corresponds to striolar and extrastriolar regions in the mammalian utricle, where Capb2 is expressed throughout. In addition, the authors assumed the zebrafish utricle and saccule perform similar functions (i.e. hearing) and contain hair cells with similar frequency tuning. It would improve this study to consider the unique functions and frequency sensitivities of the utricle and the saccule, given that different expression of voltage-gated channels may give insight into the specific physiology of these two sensory organs.

    1. Reviewer #1 (Public Review):

      The authors Rem et al., examine the mechanism of action of APP, a protein implicated in Alzheimer's disease pathology, on GABAB receptor function. It has been reported earlier that soluble APP (sAPP) binds to the Sushi domain 1 of the GABAB1a subunit. In the current manuscript, authors examine this issue in detail and report that sAPP or APP17 interacts with GABABR with nano Molar affinity. However, binding of APP to GABAB receptor does not influence any of the canonical effects such as receptor function, K+ channel currents, spontaneous release of glutamate, or EPSC in vivo. The experimental evidence provided to support the conclusions is thorough and statistically sound. The range of techniques used to address each of the aims has been carefully curated to draw meaningful conclusions.

      The authors use HEK293T heterologous cell line to confirm the affinity of APP17 for the receptor, ligand displacement, and receptor activation. They also use this method to study PKA activation downstream of the GPCR. They use slice electrophysiology to measure changes in glutamatergic transmission EPSC and then in vivo 2-photon microscopy to measure functional changes in vivo.

      The work is significant for the field of Alzheimer's and also GABAB receptor biology, as it has been assumed for sAPP acts via GABAB receptors to influence neurotransmission in the brain. The results presented here open up the question yet again, what is the physiological function of sAPP in the brain?

      The manuscript is clearly written and easy to follow. The main criticism would be that the manuscript fails to identify the mechanism downstream of APP17 interaction with GB1a SD1.

    1. Reviewer #1 (Public Review):

      This paper by Hubmann et al investigates the role of a large ECM protein in lymphangiogenesis using the zebrafish model to test genetic interactions and with state-of-the-art reporter readouts to evaluate expression patterns and vascular behaviors. The experiments examine the effects of svep1 deletion on facial lymphatics and produce the surprising result that svep1 and vegfc appear to be required in non-overlapping areas of this lymphatic vascular bed. They then use these tools and mutants for tie1 or tie2 to examine genetic interactions in this area and in parachordal lymphangioblast migration in the trunk, showing that tie1 but not tie2 shows epistasis with svep1. The data are overall rigorous and quantified to show the statistical significance of the stated results. The work provides important insights into a complex signaling pathway that is widely utilized in vascular development. The evidence is convincing in supporting the findings and is predicted to be of interest to vascular biologists and others interested in Tie/Tek signaling such as cancer biologists.

    1. Reviewer #1 (Public Review):

      Gormley et al. conduct a comprehensive Mendelian randomisation (MR) analysis to study the causal effect of obesity and metabolic disorder on oral and oropharyngeal cancer. This work follows on from observational studies that found evidence of associations between these variables and continued on from a previous MR study that focused on the effect of circulating lipid traits on these cancer outcomes. In this study, the authors found limited evidence for an effect of obesity-related traits on either cancer type, contradicting the previous observational studies and thus implying that the latter may have been affected by confounding. Sensitivity analyses that adjusted for potential pleiotropy and outlying instrumental variants agreed with the main study findings. Risk factors including smoking, risk-taking (a proxy for sexual behavior), and alcohol consumption were also stratified for, and only evidence was found for smoking as a mediator of the observed effect.

      Strengths:<br /> Strengths of this study include the thorough MR analysis conducted, with all required sensitivity analyses and checks conducted and summarised appropriately, including the use of recent MR methods such as SIMEX where required. For the disease outcomes, oral and oropharyngeal cancer, the authors used summary statistics from the single largest trans-ethnic published meta-analysis GWAS available. Known risk factors were stratified for in sensitivity analyses to follow up any results of interest. Where measures of risk factors were not directly available (e.g. sexual behaviour), genetically-correlated proxy measures were used.

      Weaknesses:<br /> While this study has several strengths, there are also a number of limitations present, many of which the authors outline in the paper. In particular, the sample size of the outcome GWAS used was rather small which may hinder the power. Also, some of the cancer subtypes of interest that had previously been investigated in observational studies were not available as GWAS, and so could not be included in this study. The authors only used European or trans-ancestry GWAS, as these are the only ancestries presently available, but a future investigation into other ethnicities is warranted. They also used risk-taking (self-defined via questionnaire) as a proxy for sexual behaviour, which despite having a strong genetic correlation, may not be the best substitute.

    1. Reviewer #1 (Public Review):

      This is an elegant article where the authors define valuable criteria to identify and classify high-confidence miRNA in fungi. The data supporting the conclusions are solid, and the results are essential to unify the annotation criteria in these organisms. Interestingly, the paper shows that miRNAs in fungi look and position within the genome more similarly to their animal counterpart but may act like plant miRNAs.

      The conclusions of this paper are well supported by data, but some aspects need to be clarified and extended.

    1. Reviewer #1 (Public Review):

      In this manuscript, the author characterizes the lattice of kinesin-decorated microtubule reconstituted from porcine tubulins in vitro and Xenopus egg extract using cryo-electron tomography and subtomogram averaging. Using the SSTA, they looked at the transition in the lattice of individual microtubules. The authors found that the lattice is not always uniform but contains transitions of different types of lattices. The finding is quite interesting and probably will lead to more investigation of the microtubule lattice inside the cells later on for this kind of lattice transition.

      The manuscript is easy to read and well-organized. The supporting data is very well prepared.

      Overall, it seems the conclusion of the author is justified. However, the manuscript appears to show a lack of data. Only 4 tomograms are done for the porcine microtubules. Increasing the data number would make the manuscript statistically convincing. In addition, having the same transition with the missing wedge orientation randomly from different subtomograms will allow a better average of transition without the missing wedge artifact.

      Another thing that I found lacking is the mapping of the transition region/alignment in the raw data. However, it is not easy for me or the reader to understand how each segment is oriented relative to each other apart from the simplified seam diagrams in the figures, and also the orientation of the seam corresponding to the missing wedge in the average. With these improvements, I think the conclusion of the manuscript will be better justified.

    1. Reviewer #1 (Public Review):

      In this manuscript, Garratt and collaborators describe exposure to male vs. female olfactory cues as an intervention modulating mouse lifespan. They use urine exposure (early life) and soiled bedding exposure (after weaning) to determine the impact of sex-specific olfactory cues on lifespan. They use wild-type and Gnao1 neural-specific mutants to determine potential dependency on vomeronasal function as well. They also recorded information about body temperature, body weight, glucose levels, grip strength, and balance. Overall, they identify female-olfactory cues as increasing the lifespan of female but not male mice, regardless of genotype.

      This study reports an intriguing new intervention with an impact on mouse lifespan (with a female-specific effect). However, some of the data with negative results are not plotted/shown, and although all experiments were performed in wild-type and mutant background, all the shown data is pooled and not split by genotype. Overall, this study will be valuable to the field provided that a few analytical points are addressed for clarity and reproducibility and that all methodological details are included.

    1. Joint Public Review:

      In this work Malis et al introduce a novel spin-labeling MRI sequence to measure cerebrospinal fluid (CSF) outflow. The glymphatic system is of growing interest in a range of diseases, but few studies have been conducted in humans due to the requirement for and invasiveness of contrast injections. By labeling one hemisphere of the brain the authors attempt to assess outflow through the superior sagittal sinus (SSS), one of the major drainage pathways for CSF, signal changes across time were assessed to extract commonly used metrics. Additionally, correlations with age are explored in their cohort of healthy volunteers. The authors report the movement of labeled CSF from the subarachnoid space to the dura mater, parasagittal dura, and ultimately SSS, evidence of leakage from the subarachnoid space to the SSS, and decreases in CSF outflow metrics with older age.

      1. I don't think that the description of Parasagittal dura in figure 1 is correct. There is no anatomical structure at the top of SSS that is known as PSD. The location of the lymphatic structures is also incorrect. Please review "Anatomic details of intradural channels in the parasagittal dura: a possible pathway for flow of cerebrospinal fluid" Neurosurgery 1996 Fox at al. There is usually no obvious tissue between the upper wall of the SSS and the calvarium, which can also be seen in the authors' fig 2A and 2B. All of the tissues located lateral to the SSS are known as PSD. Also, the SSS wall is not as thick as the authors stated and is known as PSD in this region. For this reason, the authors need to revise Fig 1 and it should be changed to PSD in the areas referred to as the SSS wall in the article.

      2. The authors described tagged CSF in two pathways: from dura mater to PSD and SAS into the SSS and directly from SAS to SSS. Flow from dura mater to PSD and SAS in the main and supplement cannot be seen. Only a flow from PSD to SSS can be seen. Also, regular dura cannot carry flow-collagen-rich fibrous tissue, except parasagittal dura. There is no flow from dura to the CSF in the figures.

      3. The authors have conducted many tests to prevent venous contamination. However, measurements were made based on SSS flow rates in all tests. Small parenchymal venous structures, and small cortical-SAS veins might be tagged due to different flow patterns and T2- Relaxation times.

      4. The rate of CSF formation in humans is 0.3 - 0.4 ml min-1. ( Brinker et al 2014. Fluids Barriers CNS). We can assume that the absorption rate is also similar to the CSF formation for the entire system brain and Spine. Therefore, the absorption rate of this very small amount of CSF by SSS is very low in seconds. It is hard to detect by MR and especially CSF flow from the PSD to SSS. The authors concluded that using this technique the rate averaged less than a couple of seconds, rather than on the order of hours or days as previously reported with the use of intrathecal administration of GBCA (Ringstad et al., 2020).

      5. Overall, I think that the CSF flow from the PSD to the CNS described by the authors - the CSF flow, might be the venous flow that drains into the SSS slowly, predominantly in the rich venous channels, venous lacunae, and previously described channels in the PSD. Additional explanations are needed.

      6. The study is generally well described and to the best of my knowledge an innovative approach. The findings are broadly consistent with what might be expected from the literature and the authors make a good argument in support of their findings. However, the lack of validation is a major limitation of the presented work. In introducing a novel technique a comparison with an existing approach, such as Gd enhanced contrast techniques, or phase contrast would have been expected. Several considerations could have been mentioned/addressed in more detail e.g. what effect labeling efficiency, tortuosity of vessels, lack of gating, the effectiveness of the intensity thresholding to remove the signal from blood, etc may have on the quantification, etc. Without a more thorough validation, it is difficult to evaluate the findings. While scans were conducted on two volunteers to assess reproducibility this is a very small sample and it is notable that scans were conducted consecutively, which might be expected to reduce variance relative to scans further apart e.g. on different dates, scanned by a different operator and no information is provided on how the two scans were positioned (i.e. separately vs copied from the first to the second scan), some metrics showed large percentage differences, which were more pronounced in one subject than the other. Without further data, it is difficult to interpret the reproducibility results. No assessment of the effect of physiological parameters e.g. breathing, cardiac pulsations, or factors affecting glymphatic clearance e.g. amount of sleep the evening before was given.

      7. Given these limitations it is hard to adequately assess the likely impact or utility. In recent years several groups have published work e.g. doi.org/10.1038/s41467-020-16002-4 , doi.org/10.1016/j.neuroimage.2021.118755 assessing the blood-CSF barrier. However, previous work has generally focused on larger structures, and by labeling in the oblique-sagittal plane it is unclear how drainage and blood flow rates may affect the presented values here.

      8. Some validation data would greatly increase the value of the reported work. I would therefore encourage the authors to consider acquiring some additional datasets to compare measures of CSF draining against another method e.g. 2-D or 4-D phase contrast, or Gd-based contrast-enhanced techniques. Some additional points to consider are noted below.

      8. Abstract

      CSF outflow may also be imaged with phase contrast MRI (albeit in a limited way).<br /> Demographics would fit better in Results, breakdown could be given for the young and old groups i.e. n, ages, sex.<br /> Conclusion - unless further validation can be provided I think some of the claims should be toned down.

      9. Introduction

      The authors emphasise the role of Nedergaard, however, there was some relevant earlier work (e.g. Rennels et al, PMID: 2396537).

      10. Methods

      It would be more conventional to summarise the volunteer characteristics in the Results.<br /> Given the age difference between the two groups, and the fact that for conventional ASL we know of differences in labelling efficiency and the need for a different post-labelling duration in more elderly patients how did the authors account for this?<br /> More broadly what would the effect of differences in labeling efficiency be, given the labeling plane is unlikely to be perpendicular to the draining vessels?<br /> While the authors mention circadian effects there is no mention of controlling for other factors before the scan e.g. caffeine consumption, smoking, etc.<br /> Various mechanisms have been hypothesised to drive glymphatic pulsations. Assessing how physiological signals correlated with the flow may have been a useful proof of concept. Why was it not considered necessary to use a gated acquisition? Did the authors consider the potential impact of respiratory and cardiac pulsations on their measurements?<br /> ROI segmentation - manually selected by two raters, was this done independently and blinded? How were consensus ROIs agreed?<br /> Intensity values outwith MEAN +/- 2 SD were excluded from further analyses. This is justified as removing pulsatile blood. However, was this done independently for tag-on and tag-off? Does this mean slight differences were present in the number of voxels between the two?<br /> The starting points and parameter ranges are given in Eq'n 3, how were the ranges defined? Was there a reason for constraining the fit to positive values only, is there a risk of bias from this?<br /> While the main results appear to have a reasonable sample size n=2 for the reproducibility analysis is very limited. Additional datasets would be useful in properly interpreting the results.

      11. Results<br /> While the authors have taken some measures to reduce potential contamination from blood I would be concerned about the risk of surface vessels affecting the signal, and there does not seem to be an evaluation of how effective their measures are.<br /> The labeling pulse is applied in the oblique sagittal orientation, but in tandem with differing rates of blood flow and CSF drainage from the labeling plane does that not risk circulating flow from other slices potentially affecting the values?<br /> Figure 4. The authors focus on the parasagittal dura, but in both the subtraction image and panel C showing different slices at TI=1250 ms some movement appears visible in the opposing hemisphere. Similarly in S2 If the signal does represent CSF movement then this seems counterintuitive and should be explained.<br /> In Figures 4 and 5 the angulation of the TIME-SLIP tag pulse seems quite different. What procedure was used to standardise this, and what effect may this have on the results?

      12. Discussion<br /> Phrasing error 'which will be assessed in future studies'.<br /> I would suggest that some of the claims of novelty be moderated e.g. 'may facilitate establishment of normative values for CSF outflow' seems a stretch given multiple pathways exist and this is only considered one.<br /> More consideration should be given to some of the points mentioned in the results. The lack of validation should be properly discussed.

    1. Reviewer #1 (Public Review):

      The authors use what is potentially a novel method for bootstrapping sequence data to evaluate the extent to which SARS-CoV-2 transmissions occurred between regions of the world, between France and other European countries, and between some distinct regions within France. Data from the first two waves of SARS-CoV-2 in Europe were considered, from 2020 into January 2021. The paper provides more detail about the specific spread of the virus around Europe, specifically within France, than other work in this area of which I am aware.

      An interesting facet of the methodology used is the downsampling of sequence data, generating multiple bootstraps each of around 500-1000 sequences and conducting analysis on each one. This has the strength of sampling, in total, a large number of sequences, while reducing the overall computational cost of analysis on a database that contains in total several hundred thousand sequences. A question I had about the results concerns the extent of downsampling versus the rate of viral migration: If between-country movements are rapid, a reduced sample could be misleading, for example characterising a transmission path from A to B to C as being from A to C by virtue of missing data. I acknowledge that this would be a problem with any phylogeographic analysis relying on limited data. However, in this case, how does the rate of migration between locations compare to the length of time between samples in the reduced trees? Along these lines, I was unclear to what extent the reported proportions of intra- versus inter-regional transmissions (e.g. line 223) would be vulnerable to sampling effects.

      A further question around the methodology was the use of an artificially high fixed clock rate in the phylogenetic analysis so as to date the tree in an unbiased way. Although I understood that the stated action led to the required results, given the time available for review I was unable to figure out why this should be so. Is this an artefact of under-sampling, or of approximations made in the phylogenetic inference? Is this a well-known phenomenon in phylogenetic inference?

      The value of this kind of research is highlighted in the paper, in that genomic data can be used to assess and guide public health measures (line 64). This work elucidates several facts about the geographical spread of SARS-CoV-2 within France and between European countries. The more clearly these facts can be translated into improved or more considered public health action, through the evaluation of previous policy actions, or through the explication of how future actions could lead to improved outcomes, the more this work will have a profound and ongoing impact.

    1. Reviewer #1 (Public Review):

      Ge et. al., examined sodium-glucose cotransporter-2 inhibitors (SGLT2i) in Alport syndrome (AS), and demonstrate that it was beneficial in AS through reduced lipotoxicity in podocytes as a key mechanism of action. The SGLT2i empagliflozin has been previously shown to have positive effects on hyperglycemia control, as well as on cardiovascular and renal outcomes of type II diabetes mellitus through tubuloglomerular feedback, but its effect on glomerular diseases such as AS are unknown to date. The authors have previously identified that cholesterol efflux in podocytes plays a critical pathogenic role in a diabetic kidney disease setting. The evidence that authors provide in favor of their hypothesis in a disease of non-metabolic origin such as AS, was supported as the SGLT2i was effective in reducing the deleterious effects of lipotoxicity in podocytes, ameliorated glomerular injury and proteinuria, and extending the life span of Col4a3 knockout mice. They further show that empagliflozin treatment mitigated AS podocytes from cell death through apoptosis, but did not impact the cell's cytotoxicity. These results support the notion that empagliflozin affects the regulation of important metabolic switch in mouse kidneys, perhaps through decreasing lipid accumulation in podocytes.

      However, the authors solely rely on one IHC staining image of a human biopsy to demonstrate SGLT2 expression in podocytes in vivo. Although the authors have done several experiments which greatly increase the confidence in their findings that empagliflozin is beneficial in AS and would have clinical significance, their data does not rule out the possibility that empagliflozin has beneficial effects through the other glomerular cells in AS, or limited to impacting lipids in podocytes in AS.

    1. Reviewer #1 (Public Review):

      This manuscript describes the generation and characterisation of a mouse knockout model of Cep78, which codes for a centrosomal protein previously implicated in cone-rod dystrophy (CRD) and hearing loss in humans. Previous work in cultured mammalian cells (including patient fibroblasts) also indicated roles for CEP78 in primary cilium assembly and length control, but so far no animal models for CEP78 were described. Here, the authors first use CRISPR/Cas9 to knock out Cep78 in the mouse and convincingly demonstrate loss of CEP78 protein in lysates of retina and testis of Cep78-/- animals. Next, by careful phenotypic analysis, the authors demonstrate significant defects in photoreceptor structure and function in these mutant animals, which become more severe over a 9 (or 18) month period. Specifically, TEM analysis demonstrates ultrastructural defects of the connecting cilium and photoreceptor outer segments in the Cep78 mutants, which is in line with previously reported roles for CEP78 in CRD and in regulating primary cilia assembly in humans. In addition to a CRD-like phenotype, the authors also convincingly show that male Cep78-/- animals are infertile and exhibit severe defects in spermatogenesis, sperm flagella structure and manchette formation (MMAF phenotype). Furthermore, the authors provide evidence for an MMAF phenotype from a male individual carrying a previously reported CEP78 c.1629-2A>G mutation, substantiating that CEP78 is required for sperm development and function in mammals and supporting previously published work (Ascari et al. 2020).

      Finally, to identify the underlying molecular mechanism by which CEP78 loss causes MMAF, the authors perform some biochemical analyses, which suggest that CEP78 physically interacts with IFT20 and TTC21A (an ortholog of Chlamydomonas IFT139) and might regulate their stability. The authors conclude that CEP78 directly binds IFT20 and TTC21A in a trimeric complex and that disruption of this complex underlies the MMAF phenotype observed in Cep78-/- male mice. However, this conclusion is not fully justified by the data provided, and the mechanism by which CEP78 affects spermatogenesis therefore remains to be clarified.

      Specific strengths are weaknesses of the manuscript are listed below.

      Strengths:

      Overall, the phenotypic characterisation of the Cep78-/- animals appears convincing and provides new evidence supporting that CEP78 plays an important role in the development and function of photoreceptors and sperm cells in vertebrates.

      Weaknesses:

      1) The immunoprecipitation experiments of mouse testis extracts that were used for the mass spectrometry analysis in Table S4 were performed with an antibody against endogenous CEP78 (although antibody details are missing). One caveat with this approach is that the antibody might block binding of CEP78 to some of its interactors, e.g. if the epitope recognized by the antibody is located within one or more interactor binding sites in CEP78. This could explain why the authors did not identify some of the previously identified CEP78 interactors in their IP analysis, such as CEP76 and the EDD-DYRK2-DDB1-VprBP complex (Hossain et al. 2017) as well as CEP350 (Goncalves et al. 2021).

      2) Figure 7A-D and page 18-25: based on IPs performed on cell or tissue lysates the authors conclude that CEP78 directly binds IFT20 and TTC21A in a "trimeric complex". However, this conclusion is not justified by the data provided, nor by the previous studies that the authors are referring to (Liu et al. 2019 and Zhang et al. 2016). The reported interactions might just as well be indirect. Indeed, IFT20 is a known component of the IFT-B2 complex (Taschner et al., 2016) whereas TTC21A (IFT139) is part of the IFT-A complex, which suggests that they may interact indirectly. In addition, the IPs shown in Figure 7A-D are lacking negative controls that do not coIP with CEP78/IFT20/TTC21A. It is important to include such controls, especially since IFT20 and CEP78 are rich in coiled coils that tend to interact non-specifically with other proteins.

      3) In Figure 7D, the input blots show similar levels of TTC21A and IFT20 in control and Cep78-/- mouse testicular tissue. This is in contrast to panels E-G in the same figure where TTC21A and IFT20 levels look reduced in the mutant. Please explain this discrepancy.

      4) The efficiency of the siRNA knockdown shown in 7J-M was only assessed by qPCR (Figure S4), but this does not necessarily mean the corresponding proteins were depleted. Western blot analysis needs to be performed to show depletion at the protein level. Furthermore, it would be desirable with rescue experiments to validate the specificity of the siRNAs used.

      5) Figure 7I: the resolution of the IFM is not very high and certainly not sufficient to demonstrate that CEP78, IFT20 and TTC21A co-localize to the same region on the centrosome, which one would have expected if they directly interact.

      6) It is not really clear what information the authors seek to obtain from the global proteomic analysis of elongating spermatids shown in Figure 3N, O and Tables S2 and S3. Also, in Table S2, why are the numbers for CEP78 in columns P, Q and R so high when Cep78 is knocked out in these spermatid lysates? Please clarify.

      7) Figure 1F and Figure 4K: the data needs to be quantified.

      8) Figure 2A: It is difficult to see a difference in connecting cilium length in control and Cep78-/- mutant retinas based on the images shown here.

    1. Reviewer #1 (Public Review):

      The idea that a passive living being can improve the wind dispersal of its seeds by passively changing their drag is enticing. The manuscript shows that high wind events in Scotland are inversely correlated with the ambient humidity. The dandelion pappus morphs with the ambient humidity, being more open in dry conditions, which is associated with stronger wind events. This passive morphing of the shape of the pappi thus leads to a dispersal of the seeds further away from their origin.

      The analysis and discussion in the paper is focused on "distance", i.e., how far the pappus will fly. Could the notion of time be relevant too? In wet conditions, perhaps it's better for a seed to hit the ground quickly and start germinating, whereas if its dry, staying up in the air for longer to travel farther might be a better strategy.

    1. Reviewer #1 (Public Review):

      This paper shows that sibling neurons in the zebrafish spinal cord have different inputs and outputs, and do not show interconnectivity - somewhat surprising considering their very similar development. The differences in sibling neuron connectivity are strongly correlated with the level of Notch signaling, suggesting that Notch signaling regulates circuit assembly.

    1. Reviewer #1 (Public Review):

      3' UTR-derived sRNAs are increasingly recognized as post-transcriptional regulators of diverse bacterial processes. While initially assumed to be highly specific regulators with single targets, global RNA interactome approaches challenge this view by suggesting 3'-derived sRNAs can bind and regulate multiple target mRNAs, reminiscent of the regulons of intergenic sRNAs (PMID: 35388892). In Enterobacteriaceae, GlnZ is an sRNA derived from the 3' UTR of the glnA mRNA (PMID: 15718303) that encodes glutamine synthetase. However, the role and function of GlnZ have not previously been determined. In the present work, the authors set out to investigate GlnZ in E. coli and Salmonella enterica. In doing so, they uncover the mechanism of GlnZ biogenesis, namely RNase E-mediated release from the parental glnA mRNA. Additionally, they identify several GlnZ targets (involved in carbon/nitrogen metabolism), some of which are conserved between E.coli and Salmonella while others are species-specific. Downstream mutational characterization of sRNA variants and experiments with target reporter constructs allow them to map sRNA-target interaction sites at nucleotide resolution. Together, their findings further support the idea that 3'-derived sRNAs, too, can act as more global post-transcriptional regulators with multiple direct targets.

      This is a thoroughly conducted study and both, important and timely. As the corresponding author points out in the cover letter, this is an instance of similar findings being simultaneously reported by more than one group (see preprint from Gisela Storz' lab: https://www.biorxiv.org/content/10.1101/2022.04.01.486790v1). The results of these two, independently conducted studies largely agree and complement one another.

    1. Reviewer #1 (Public Review):

      In this article, Susswein and colleagues use SafeGraph mobile device location data to characterize seasonal trends in indoor activity in the United States at the county level with relevance for respiratory disease transmission. They find substantial variation in indoor activity over the course of the year, ranging from roughly 25% (summer trough) to 200% (winter peak) of the average/baseline indoor activity in each county. Additionally, they identify two main regions with distinct seasonal trends in indoor activity: one in the north, where indoor activity follows a roughly standard sinusoidal trend, and one in the south where indoor activity may feature an additional summer peak. They also identify a third minor region with spring and fall peaks in indoor activity, corresponding to mountainous areas that are hubs for winter tourism. Using a simple mathematical disease transmission model, they demonstrate that using different seasonal forcing terms as inputs can yield substantially different epidemic curves.

      This study's main strength is the volume and resolution of the data. Because of this, the authors are able to provide convincing evidence that seasonal variation in indoor activity exists, that it is substantial, and that it varies geographically across the US. Another important strength is the approach that the authors used to identify regions with similar seasonal trends in indoor activity. By using a network community detection algorithm, they were able to avoid making a priori assumptions about the number, size, and geographic connectivity of the regions, allowing them to make better use of the data itself to inform the delineation between regions.

      Despite the volume of the underlying dataset, it is geographically limited to the United States and only captures the locations of mobile devices for which their users have opted in to sharing location data. This calls into question the generalizability of the findings to other countries and to other populations within the US that may have reduced access to mobile devices or may be less likely to share location data. The assessment of between-county differences in seasonal indoor activity trends and the assessment of the impact of the COVID-19 pandemic on indoor activity could benefit from greater detail, as they currently rest mainly on visual inspection of the trends.

      Overall, the authors have largely achieved their aims of characterizing indoor seasonal activity in the United States at a fine geographic resolution. This work will be immediately useful for the construction of more evidence-based infectious disease transmission models. The authors have made available their estimates of seasonal deviation in indoor activity at the county level, which can be incorporated directly into disease transmission models. Their descriptions are also sufficient for building models that do not incorporate the full county-level detail but nevertheless account for important regional differences in indoor activity across the US.

    1. Reviewer #1 (Public Review):

      This paper elucidates the developmental-genetic mechanisms that generate the winged and wingless form (morph) of female pea aphids (Acyrthosiphon pisum). Pea aphids reproduce parthenogenetically generating genetically identical offspring, and so the difference between the winged and wingless morphs is environmentally induced (referred to as a polyphenism). Previous studies have shown that the crowding of mothers is sufficient to induce the winged phenotype in the offspring. The authors develop a technique so that they can reliably generate wing-destined (WD) or wingless-destined (WLD) offspring. This allowed them to examine the early development of WD and WLD offspring during the 1st nymphal stage, before wing development can be observed externally, in the 3rd nymphal stage. They find that the wing primordia are apparent in both WD and WLD 1st instars immediately after birth, but that the primordia degrades 30-36h after birth in WLD nymphs. They then demonstrate that this degeneration is due to autophagy rather than apoptosis, evident through the increased expression of autophagy-related genes in WLD nymphs, but not pro-apoptotic genes. The authors next ask what is responsible for inducing autophagy in the WLD nymphs and so transcriptomics to look for genes that are differentially up- or down-regulated in 1st insar WLD versus WD nymphs. One gene, REPTOR2, is markedly down-regulated in WLD versus WD nymphs. REPTOR is an established target of TOR-signaling, which is in turn an established regulator of autophagy. The authors, therefore, focus on REPTOR2 and show that it has arisen through gene duplication of REPTOR in the A. pisum lineages, that it is differentially upregulated in the thorax of WLD versus WD nymphs, and that knock-down of REPTOR2 both reduces levels of the autophagic protein ATG8 in the wing primordia of 1st instar nymph and increases the proportion of winged offspring. Finally, the authors demonstrate that TOR, which canonically represses RAPTOR, negatively regulates autophagy of the wing primordia and positively regulates the generation of the winged morph.

      The strength of this paper is that it cleanly implicates a novel gene, REPTOR2, that has arisen through gene duplication, in the generation of alternative morphs in a polyphenism. The paper also provides compelling evidence that the degeneration of the wing primordia in wingless aphids is through autophagy rather than apoptosis. Further, the paper provides another example of how signaling pathways known to be involved in the generation of reaction norms (continuous phenotypic responses to environmental variation) are also implicated in the generation of polyphenisms (discrete phenotypic responses to environmental variation). The paper uses a reliable and reproducible technique to generate wing and wingless forms of aphids upon which developmental studies can be conducted. The results of the paper are straightforward and convincing. A weakness of the paper is that, while it implicates both RAPTOR2 and TOR-signaling in the generation of winged and wingless morphs, it does not provide a causal link between the two. REPTOR (Repressed by TOR) is known to be a regulator of TOR-signaling in Drosophila, activating transcriptional stress response upon TOR inhibition, and the authors argue that REPTOR2 serves to exert a negative effect of TOR signaling on autophagy initiation in wingless aphids. Nevertheless, their data do not unambiguously show this. Specifically, they do not demonstrate that REPTOR2 is downstream of TOR in the signaling pathway that regulates winglessness.

    1. Reviewer #1 (Public Review):

      In a very interesting and technically advanced study, the authors measured the force production of curved protofilaments at depolymerizing mammalian microtubule ends using an optical trap assay that they developed previously for yeast microtubules. They found that the magnesium concentration affects this force production, which they argue based on a theoretical model is due to affecting the length of the protofilament curls, as observed previously by electron microscopy. Comparing with their previous force measurements, they conclude that mammalian microtubules produce smaller force pulses than yeast microtubules due to shorter protofilament curls. This work provides new mechanistic insight into how shrinking microtubules exert forces on cargoes such as for example kinetochores during cell division. The experiments are sophisticated and appear to be of high quality, conclusions are well supported by the data, and language is appropriate when conclusions are drawn from more indirect evidence. Given that the experimental setup differs from the previous optical trap assay (antibody plus tubulin attached to bead versus only antibody attached to bead), a control experiment could be useful with yeast microtubules using the same protocol used in the new variant of the assay, or at least a discussion regarding this issue. One open question may be whether the authors can be sure that measured forces are only due to single depolymerizing protofilaments instead of two or more protofilaments staying laterally attached for a while. How would this affect the interpretation of the data?<br /> This work will be of interest to cell biologists and biophysicists interested in spindle mechanics or generally in filament mechanics.

    1. Reviewer #1 (Public Review):

      In this work, Li & Meister provide an extensive description of functional cell types within the posterior-medial part of the mouse superior colliculus, corresponding to the upper lateral visual field. Presenting a battery of visual stimuli to head-fixed wild-type mouse lines, they use calcium imaging and subsequent clustering of functional responses to identify 24 functional cell types. Besides the comprehensive sampling of SC cell types, a major strength of the manuscript in my view is the direct comparison with the previously published in vitro RGC data. Overall, the manuscript and the associated data promise to be a valuable resource to experimentalists and computational neuroscientists comparing visual processing across the major processing stages of the mouse visual system. However, in the current form the manuscript still comes with some limitations. In my view, these are related to some parts, where statistical justifications for the conclusions are still missing, where the findings should be more strongly embedded into the current and past literature, and where more efforts should be made to relate the findings in the different mouse lines to those for the overall population.

    1. Reviewer #1 (Public Review):

      The authors have generated a set of seven nanobody tools against two of the largest Drosophila proteins, which are related to vertebrate titin and essential for muscle function. The study of such gigantic proteins is a challenge. They show that each of these nanobodies recognizes their epitope with high affinity (as expected from antibodies), fails to generate a signal after immune-fixation of a mutant for the cognate protein, do not cross-react with each other, and generates a signal in the muscle that makes sense with what one would anticipate for fly titin homologs. In addition, they show that these nanobodies have better penetration and labeling efficiency than conventional antibodies in thick tissues after classical paraformaldehyde fixation. Using these nanobodies, they could deduce the organization of the epitopes in different muscle types and propose a model for Sallimus and Projectin arrangement in muscles, including in larvae which are difficult to label with traditional antibodies due to their impermeable chitin skeleton. Finally, they could fuse the gene encoding one of the nanobodies to the open reading frame of NeonGreen and express the corresponding fusion protein in animals to use the probe in FRAP assays.

      The work is very well performed and convincing. However, given its significant redundancy in terms of biological conclusions with the companion study "Nanobodies combined with DNA-PAINT super-resolution reveal a staggered titin nano-architecture in flight muscles" by the same authors, and other published papers, I recommend the authors further prove the use of their nanobodies in live assays. In particular, the authors should test whether they can use the nanobodies to induce protein degradation either permanently or conditionally.

    1. Reviewer #1 (Public Review):

      The authors found that the IDR in Cdc15 gets phosphorylated by multiple kinases, Pom1/Shk1/Pck1/Kin1, and the phosphorylation on IDR inhibits the phase separation of the Cdc15 protein. The phosphorylation was demonstrated in the cell as well as in vitro. Moreover, the phosphorylation sites were identified by mass spectrometry. The phospho-regulation of Cdc15 LLPS was demonstrated by in vitro assay using recombinant proteins. The significance of the phosphorylation on contractile actomyosin ring (CAR) was demonstrated by using a cdc15 mutant carrying 31 Ala-substitutions at the phosphorylation sites (cdc15 31A). The CAR assembled comparable to cdc15+, but maturation and contraction of the ring were faster in the cdc15 31A mutant, suggesting the contribution of the phosphorylation for delaying cytokinesis. This could be one of the mechanisms to ensure the completion of chromosome segregation before the cytokinesis. In this paper, the authors showed over-accumulation of type-II myosin regulatory light chain Rlc1 on CAR in the cdc15 31A mutant during the CAR assembly and its contraction. In addition, the kinases for the Cdc15 IDR phosphorylation are identified as polarity kinases, which restrict the assembly of the CAR formation in the middle. Indeed, inhibition of the kinases increases the ratio of septa formation at the cell tip in the mid1 knockout mutant, which lacks a major positive polarity cue during the mitotic phase. However, in this manuscript, this phenotype is not solely explained by the phosphorylation of the cdc15 31A, because the authors did not show the tip septa formation using cdc15 31A.

      Overall, the data supports their conclusion, Cdc15 forms LLPS, and the process is inhibited by the phosphorylation of amino acid residues in the IDR in Cdc15 by polarity kinases. It is still unclear whether LLPS formation is a reversible process regulated by the protein kinases. In vitro experiments showed condensate formation by dephosphorylation of Cdc15 IDR but not diffusion of the LLPS by phosphorylation. I wonder if incubation of the kinases and the Cdc15 IDR condensates induces demolition of the LLPS.

      The transition of the Cdc15 IDR phosphorylation and LLPS formation through the cell cycle progression is unclear. In asynchronous cells (most of the cells may be in the G2 phase) and nda3 or cps1 mutants, Cdc15 was still highly phosphorylated. This indicates that the Cdc15 is phosphorylated and the LLPS formation is inhibited throughout the cell cycle. The transition of the phosphorylation status for individual residues could be the next challenge for this research. In addition, currently, there is no approach to monitor the LLPS in wild-type cells. Therefore, it is still unclear if LLPS formation is the physiological mechanism regulating cell division in wild-type cells.

    1. Reviewer #1 (Public Review):

      This paper tests whether people vary their reliance on episodic memory vs. incremental learning as a function of the uncertainty of the environment. The authors posit that higher uncertainty environments should lead to more reliance on episodic memory, and they find evidence for this effect across several kinds of analyses and across two independent samples.

      The paper is beautifully written and motivated, and the results and figures are clear and compelling. The replication in an independent sample is especially useful. I think this will be an important paper of interest to a broad group of learning, memory, and decision-making researchers. I have only two points of concern about the interpretation of the results:

      1. My main concern regards the indirect indicator of participants' use of episodic memory on a given trial. The authors assume that episodic memory is used if the value of the chosen object (as determined by its value the last time it was presented) does not match the current value of the deck it is presented in. They find that these mismatch choices happen more often in the high-volatility environment. But if participants simply choose in a more noisy/exploratory way in the high volatility environment, I believe that would also result in more mismatched judgments. What proportion of the trials labeled as episodic should we expect to be a result of noise or exploration? It seems conceivable that a judgment to explore could take longer, and result in the observed RT effects. Perhaps it could be useful to match up putative episodic trials with later recognition memory for those particular items. The across-subjects correlations are an indirect version of this, but could potentially be subject to a related concern if participants who explore more (and are then judged as more episodic) also simply have a better memory.

      2. The paper is framed as tapping into a trade-off between the use of episodic memory vs. incremental learning, but it is not clear why participants would not use episodic memory in this particular task setup whenever it is available to them. The authors mention that there is "computational expense" to episodic memory, but retrieval of an already-established strong episodic memory could be quite effortless and even automatic. Why not always use it, since it is guaranteed in this task to be a better source of information for the decision? If it is true that RT is higher when using episodic memory, that is helpful toward establishing the trade-off, so this links to the concern above about how confident we can be about the use of episodic memory in particular trials.

    1. Reviewer #1 (Public Review):

      Trudel and colleagues aimed to uncover the neural mechanisms of estimating the reliability of the information from social agents and non-social objects. By combining functional MRI with a behavioural experiment and computational modelling, they demonstrated that learning from social sources is more accurate and robust compared with that from non-social sources. Furthermore, dmPFC and pTPJ were found to track the estimated reliability of the social agents (as opposed to the non-social objects).

      The strength of this study is to devise a task consisting of the two experimental conditions that were matched in their statistical properties and only differed in their framing (social vs. non-social). The novel experimental task allows researchers to directly compare the learning from social and non-social sources, which is a prominent contribution of the present study to social decision neuroscience.

      One of the major weaknesses is the lack of a clear description about the conceptual novelty. Learning about the reliability/expertise of social and non-social agents has been of considerable concern in social neuroscience (e.g., Boorman et al., Neuron 2013; and Wittmann et al., Neuron 2016). The authors could do a better job in clarifying the novelty of the study beyond the previous literature.

      Another weakness is the lack of justifications of the behavioural data analyses. It is difficult for me to understand why 'performance matching' is suitable for an index of learning accuracy. I understand the optimal participant would adjust the interval size with respect to the estimated reliability of the advisor (i.e., angular error); however, I am wondering if the optimal strategy for participants is to exactly match the interval size with the angular error. Furthermore, the definitions of 'confidence adjustment across trials' and 'learning index' look arbitrary.

      As the authors assumed simple Bayesian learning for the estimation of reliability in this study, the degree/speed of the learning should be examined with reference to the distance between the posterior and prior belief in the optimal Bayesian inference.

    1. Reviewer #1 (Public Review):

      The Voeltz lab in previous work has established a physical connection between the endoplasmic reticulum and mitochondria as an organizing principle in mitochondrial fission and fusion. A key cytoplasmic protein, Drp1 and a mitochondrial outer membrane protein, Mfn1, are known to localize to nodes of interaction between the ER and mitochondria but until now, no ER membrane proteins required in this process have been described. Using a Turbo ID fused to Mfn1, the authors have identified a known ER membrane protein that interacts with functional Mfn. This ER membrane protein, which they call Aphyd1, contains putative acyl hydrolase and acyltransferase domains. Further, in compelling work combining high resolution fluorescence microscopy and gene function analysis they have described the role of this protein in the recruitment of Drp1 and Mnn1 to nodes of interaction between the ER and mitochondria and in the sequential processes of mitochondrial constriction, fission and fusion. The work is clear and nicely quantitative and adds a new molecular element to the important question of how the ER serves to organize the division and fusion of mitochondria.

    1. Reviewer #1 (Public Review):

      This manuscript clearly demonstrates that murine malaria infection with Plasmodium chabaudi impairs B cells' interaction with T cells, rather than DCs interaction with T cells. The authors elegantly showed that DCs were activated, capable of acquiring antigens and priming T cells during P. chabaudi infection. B cells are the main APC to capture particulate antigens such as infected RBC (iRBC), while DCs preferentially take up soluble antigens. This study is important to understand how ongoing infections such as malaria may negatively affect heterologous immunizations.

      Overall, the experimental designs are straightforward, and the manuscript is well-written. However, there were several limitations in this study.

      Specific comments:

      1. The mechanism of how the prior capture of iRBC by B cells lead to the impairment of B-T interaction was not understood. It is unclear whether the impairment of B-T cell interaction is due to direct BCR interaction with iRBC, or an indirect response to extrinsic factors induced by malaria infection.

      2. Would malaria infection in MD4 mouse that carries transgenic BCR that does not recognize malaria parasite impair subsequent B cell response to HEL immunization? This may clarify whether the impairment of subsequent B cell response is BCR-specific. If malaria impairs subsequent B cell response to HEL in MD4 mouse, it might suggest that other cell types and B cell-extrinsic factors might be involved in causing the impaired B cell responses, instead of malaria affecting B cells directly.

      3. MD4 mice were mentioned in the Methods in vitro RBC binding, although none of the figures described the usage of MD4 mice. This experiment data might be important to show whether RBC binding to B cells is mediated through BCR.

      4. Does P. chabaudi infection have any effects on B cell uptake of subsequent antigens, such as soluble antigen PE or particulate antigen CFSE-labeled P. yoelii iRBC?

      5. Is this phenomenon specific to malaria infection? Does malaria-irrelevant particulate immunization affect T-B interaction of subsequent heterologous immunization?

      6. Despite the impaired Tfh and GC 8 days after immunization following malaria infection, Fig. 5F showed GP-specific IgG eventually increased to the same level as the uninfected immunized mice on day 23. Did the authors check whether these mice had a delayed Tfh and GC response that eventually increase on day 23? Are these antibody responses derived from GC, or GC-independent response?

      7. Does recovery from malaria infection by antimalarial treatment rescue the B cell response to subsequent heterologous immunization?

      8. Fig. 1C shows more nRBC was taken up than iRBC in B cells, but Line 142 states that "B cells bound significantly more iRBC than nRBC. Is there a mistake in the figure arrangement? Why do B cells take up for naïve RBC than iRBC?

      9. Fig. S1 C and D are confusing. CD45.1+ CD45.2+ mouse did not receive labeled iRBC, but why iRBC was detected as much as 40% in the spleen of this naïve mouse?

    1. Reviewer #1 (Public Review):

      This paper details the creation and data behind the website http://pandemics.okstate.edu/covid19/. The authors attempt to explore if there is a cause and effect between the detection of unusually increased mutation activity in the genomic surveillance databases and subsequent near-term surges in SARS-CoV-2 case numbers.

      Overall the premise is interesting as other than following case numbers reported to health authorities and observing what is happening in another country, there is no reliable way to predict when a surge is going to occur. Unfortunately, the data demonstrate that there was no reliable metric that could be used to predict surge events. Interestingly, the website has issued a "surge alert" currently for the month of September. It will be interesting to observe whether their model indeed has predictive power or whether the current analysis is merely coincidental with the surges but not necessarily predictive of them.

    1. Reviewer #1 (Public Review):

      This interesting manuscript by Goto and Miyamichi analyses calcium dynamics in the kisspeptin neurons of the arcuate nucleus of the hypothalamus during the estrous cycle and during reproductive aging in female mice. In particular, the authors succeed in tracking arcuate kisspeptin calcium activity in the same mice over 10 months, which is quite impressive and brings highly valuable information. The authors demonstrate that the frequency and the amplitude and waveforms of individual synchronous episodes of arcuate kisspeptin neuronal activation vary across the estrous cycle. Unexpectedly, however, aging does not appear to alter markedly calcium dynamics in these neurons.

    1. Reviewer #1 (Public Review):

      Ferroportin (Fpn) is a Fe2+/H+ antiporter that extrudes Fe2+ from cells and is important for iron homeostasis. Using a combination of proteoliposome assays, mutagenesis and structural studies by cryo EM the authors are aiming to demonstrate that the Fpn-transporter is also capable of Ca2+ influx, indicating a novel route for Ca2+ entry into cells.

      Strengthens: The paper combines a number of different methods to robustly demonstrate the interaction of Ca2+ with the iron transporter and to show translocation of Ca2+ is not pH dependent.

      Weaknesses: Fpn uses proton-gradient to drive Fe2+ efflux. The proposal is that the antiporter can also passively uptake Ca2+. This means that after Ca2+ release on the inside, Fpn would need to spontaneously rest to the outside again, which it has not evolved to do in the absence of Fe2+. To provide further support for Ca2+ uptake it is important to show that there are mutiple turnovers of the transporter, i.e., more kinetic information is needed,

      The impact of this paper is the demonstration that transporters (exchangers) can also operate as facilitative transporters for other substrates. The study also implies that Ca2+ can enter cells by this pathway, but if so the physiological context of this entry route needs further investigation and/or justification.

    1. Reviewer #1 (Public Review):

      Here the authors set out to disentangle neural responses to acoustic and linguistic aspects of speech. Participants heard a short story, which could be in a language they understood or did not (French vs. Dutch stories, presented to Dutch listeners). Additional predictors included a combination of acoustic and linguistic factors: Acoustic, Phoneme Onsets, Phoneme Surprisal, Phoneme Entropy and, Word Frequency. Accuracy of reconstruction of the acoustic amplitude envelope was used as an outcome measure.

      The use of continuous speech and the use of comprehended vs. uncomprehended speech are both significant strengths of the approach. Overall the analyses are largely appropriate to answer the questions posed.

      The reconstruction accuracies (e.g., R^2 values Figure 1) seem lower perhaps than might be expected - some direct comparisons with prior literature would be welcome here. Specifically, the accuracies in Figure 1A are around .002-.003 whereas the range seen in some other papers is about an order of magnitude or more larger (e.g. Broderick et al. 2019 J Neurosci; Ding and Simon 2013 J Neurosci).

      One theoretical point relevant to this and similar studies concerns the use of acoustic envelope reconstruction accuracy as the dependent measure. On the one hand, reconstruction accuracy provides an objective measure of "success", and a satisfying link between stimulus and brain activity. On the other hand, as the authors point out, envelope reconstruction is probably not the primary goal of listeners in a conversation: comprehension is. Some discussion of the implications of envelope reconstruction accuracy might be useful in guiding interpretation of the current work, and importantly, helping the field as a whole grapple with this issue.

      Overall, the results support the authors' conclusions that acoustic edges and phoneme features are treated differently depending on whether a listener comprehends the language being spoken. In particular, phoneme features contribute to a greater degree when language is comprehended, whereas acoustic edges contribute similarly regardless of comprehension. These findings are important in part because of prior work suggesting that acoustic edges are critically important for "chunking" continuous speech into linguistic units; the current results re-center language units (phonemes) as critical to comprehension.

    1. Reviewer #1 (Public Review):

      In this genetic and imaging based analysis of stem-cell maintenance and organ initiation, two phases important for continued production of shoot organs in plants, the authors tested whether SHR and targets/partners (SCR, SCL23, JWD) provide the circuitry to maintain stem cell pool and contribute to the production of lateral organs. Finding that these factors are indeed expressed in and required for SAM activities, and furthermore, behaviors of SHR and SCR in the root are recapitulated in the meristem, including mobility of SHR (here to epidermis from internal layers), activation of SCR by SHR, and "trapping" of SHR movement by complexing with SCR. Strengths include high quality imaging of reporters and FRET-FLIM measurement to assess in vivo complex formation. The analysis is then extended to link SHR and SCR to shoot-specific factors and auxin, again by testing expression, genetic dependencies and physical interaction. This is repeated for a number of factors and individually, each is well done experiment. Conclusions about causal relationships are somewhat overstated (for example, the idea that SHR-SCR act through CYCD6 to alter cell division is based on expression patterns, not a functional analysis of cycd6).

      In general, there are many high-quality studies included in this paper, and the presentation of imaging data (both the images themselves and quantification of data) is excellent. There is also a lot of data, and while each section was presented in a logical way, connections between sections, and the overarching developmental questions were sparse. Because the authors found that many of the relationships defined in the root were recapitulated in the shoot, the present organization leaves one with somewhat of a sense that little new was learned, and yet, the shoot meristem IS different and there are shoot specific inputs into the core regulatory factors. Rewriting to highlight the different activities (and thus expectation about regulation) could make the finding of the same network more interesting and creating a summary figure that highlights the input of shoot specific signals would bring the unique analysis to the forefront.

    1. Reviewer #1 (Public Review):

      In this manuscript, the authors present a suite of statistical models that can identify patterns of somatic single base mutational signatures (SBS), insertions, deletions, and structural rearrangements predictive of DNA damage response (DDR) gene deficiency. A similar approach (HRDetect) has already proved successful in identifying BRCA1/BRCA2 deficiency in breast cancers and other tumor types. To generate their models, Sørensen and colleagues consider over 700 DDR gene deficiencies across more than 6,000 patients enrolled through the Hartwig Medical Foundation and PCAWG studies. The authors also consider the full set of COSMIC SBS reference signatures. The models recapitulate known associations between BRCA1/2,TP53, and CDK12 and mutational patterns but also characterize previously undescribed associations involving ATRX, PTEN, CDKN2A, and SMARCA4. Many of these novel models generalize across different tumour types and also primary and metastatic cancers. The authors also consider negative coefficient features in their models which is worthwhile and present hypotheses supporting how negative features might arise. One of the further strengths of the study is its innovative reuse of large-scale cancer genome data sets leading to predictive models with potential use for clinical intervention and demonstrating the potential of using WGS mutational signatures to guide cancer treatment. Many of the findings and observations presented in the paper have the collateral potential to enhance our understanding of the aetiology of SBS signatures. While I don't think the paper presents any major conceptual and technical advances in terms of methodology, the manuscript is important, interesting, and timely.

    1. Reviewer #1 (Public Review):

      This work by Olesen et al provides a clear and thorough examination of participation in organised colorectal cancer screening in Denmark over 2018-2021, with a particular focus on potential impacts of the COVID-19 pandemic. There is also an analysis by population subgroups that offers additional insight into how the pandemic may have affected participation.

      The key strength of this manuscript is access to the presumably complete data from Danish Colorectal Cancer Screening Database, with only a small proportion of individuals being excluded for sensible reasons. Combined with a standard statistical analysis, the results are clear and inarguable.

      A weakness is that the manuscript is wholly quantitative. Therefore some of the observations made, particularly for population subgroups, cannot be explained within the scope of this manuscript. The authors have provided hypotheses to explain these, but without further research no firm conclusion can be made.

      Another weakness is that, due to the nature of screening, no conclusions can be made on the health impact of COVID-related changes to screening. It is unclear whether small reductions in screening and colonoscopy follow-ups is likely to lead to additional cancers, or later-stage diagnoses.

      This manuscript, together with similar analyses in other settings worldwide, provides both an overview of how the COVID-19 pandemic has affected screening, but also potentially guidance for how future potential disruptions should be managed in the cancer screening space. By considering the potential downstream impact of changes to screening, and balancing these against potential harms and resource restrictions associated with (eg) attending health services during a pandemic, policymakers can make informed decisions to manage future shutdowns.

    1. Reviewer #1 (Public Review):

      Liu, et al. describe an essential role for prostaglandin signaling during neonephrogenesis in the zebrafish kidney following acute kidney injury. They identified that renal interstitial cells are the source of prostaglandin, and demonstrated which components of the prostaglandin biosynthesis pathway as well as which receptor is involved in the signaling. Further, they determined the mechanism by which PGE2 stimulates the proliferation of renal progenitor cells which make the new nephrons, namely to regulate B-catenin levels. This work is systematic, thorough, and well-controlled. The applications of these findings may have a profound impact on the formulation of regenerative medicine treatments for kidney disease.

    1. Reviewer #1 (Public Review):

      Tan and colleagues examine the role of additional genetic removal of Munc13 in murine cultured synapses deficient for RIM and ELKS. They utilize a comprehensive set of morphological, ultrastructural and functional experiments to conclude that Munc13 is a nonredundent factor in synaptic vesicle priming. In addition, the results contribute to the ongoing discussion whether synaptic vesicle docking represents synaptic vesicle priming.

      The main strength of the work is the use of a sophisticated genetic model, and the quality of the performed experiments. The results strongly support the conclusion of the nonredundant role of Munc13 in synaptic vesicle priming.

      The weakness of the paper is that the findings from these study has limited impact, as the genetic and functional interaction of Munc13 and RIM has been extensively analyzed on a qualitative and quantitative level (Kaeser 2021, Zarebidaki 2020). While this paper benefits from the additional deletion of ELKS, the specific contribution of ELKS in comparison to the older studies is not in the focus of the study.

      While the genetic removal of all 6 genes involved clearly require the use of conditional KO mice, the resulting outcome of the experimental design is a hypomorphic phenotype, as neurotransmitter release is still detected. This complicates the interpretation of the findings and weakens the strength of the conclusions.

    1. Reviewer #1 (Public Review):

      This manuscript addressed an important question regarding an obstacle to hair reprogramming in older mice that is not present in newborn mice. The conclusions were justified by experimental results. However, the scientific novelty is limited, and there is a lack of functional characterization of the newly formed hair cells.

      There are several strengths of this study: 1. It addressed a significant question as hearing loss is an important public health issue. 2. Well-designed genetic approaches. 3. Experiments were well designed and justified. 4. Experimental results are convincing. 5. Conclusions were well justified by experimental results. There are also several weaknesses:

      1. The scientific novelty is limited. It is known that overexpression of several transcription factors simultaneously can reprogram hair cells and non-hair cells with hair cell characteristics.

      2. Transcription factor Atoh1 and downstream GFI1and POU4F3 have been used to reprogram embryonic stem cells and chick otic epithelial cells in vitro to cells expressing several hair cell genes and displaying key hair cell features.

      3. There is no functional characterization of newly reprogramed hair cells in adult mice although FM 1-43 dye was used for characterizing reprogramed hair cells in neonatal mice.

      4. It is not understood why the changes in transduction channel protein expression were not highlighted in gene analysis.

      5. It will be nice if hair cell-like electrophysiological properties can be found in newly reprogramed hair cells.

    1. Reviewer #1 (Public Review):

      The authors investigate whether and how PFA fixation affects the structures formed by some proteins that undergo LLPS. They do that by over-expressing a number of constructs in cells and imaging them by live cell fluorescence microscopy, after which they fix the cells and image the same cell after fixation. Their results clearly show that, for different proteins and with different tags, there is a non-systematic alteration of the LLPS structures.

      In parallel to this experimental work, the authors also present and analyze a dynamic computational model in which they investigate how different fixation rates for those proteins inside and outside the condensates can lead to alterations in the overall condensate organization after fixation. Their model shows that if the fixation rate inside the condensate is different than outside the condensate, and if the dynamics of protein exchange in/out of the condensates are fast enough, fixation artifacts are to be expected.

      It remains to be seen whether the alterations in condensate structures after fixation (as seen experimentally) are caused by different fixation rates (as shown computationally).

      Overall, this manuscript puts forward an important observation, on how chemical fixation can alter cellular structures, such as those of membraneless organelles.

    1. Reviewer #1 (Public Review):

      There are five major claims. First is a replication of lower spatial frequency representation in V4. This is based on two examples shown in Fig. 3. The differences look clear but should be analyzed statistically.

      The second claim is that, on the large scale of the visual field representation in V2 and V4, spatial frequency is mapped from high to low going from fovea to periphery, here estimated as lateral to medial, as in V1. The analysis for this is to plot the geometric centroids of 6 different spatial frequency band responses, for orientation contrasts (Fig. 4A) and color contrasts (Fig. 4B), and show that they progress in position from lateral to medial for high to low frequencies. This seems like an unusual analysis that obscures most of the original data concerning the relationship of spatial frequency response profiles to the two-dimensional imaging area. And, the centroids do not show a continuous map, but rather a bunching of points except for the extremes. The additional data are 4 supplemental examples with three, different frequency ranges. These data are not analyzed statistically.

      The third and most important claim is that spatial frequency and orientation are mapped orthogonally (and recursively) in V2 and V4, as seen in Fig. 5 and the Fig. 5 supplement. Together these figures present two regions in V4 and two regions in V2. If these are the only analyzed regions, the authors need to specify more clearly how they were selected. Presumably, though, other regions were analyzed, and the authors should present results from all analyzable regions, and use statistical analyses to establish significance.

      The fourth claim is that color-sensitive regions in V4 are more associated with low spatial frequencies. The one significant example (the analysis and statistical tests need to be explained), shown in Fig. 6, shows a weak relationship to color for both spatial frequency bands, and the other examples presented in the supplementary are not significant and have even lower absolute relationships. These results, if presented, should be considered inconclusive.

      The fifth claim is for stripe-like periodicity of spatial frequency representation in V2, related to color tuning. This is supported by ostention to binary maps of spatial frequency tuning in Fig. 7 and supplement. Establishing this periodicity would require statistical analysis, and in any case, seems impossible since only a sliver of V2 is visible in these brain surface images, so stripes orthogonal to the V1/V2 boundary (i.e. CO stripes) cannot be distinguished from other patterns of spatial frequency tuning. In fact, Fig. 5E and S5I do not appear to have iso-frequency contours biased toward that orientation.

    1. Reviewer #1 (Public Review):

      Auwerx et al. have taken a new approach to mine large existing datasets of intermediary molecular data between GWAS and phenotype, with the aim of uncovering novel insight into the molecular mechanisms which lead a GWAS hit to have a phenotypic effect. The authors show that you can get additional insight by integrating multiple omics layers rather than analyzing only a single molecular type, including a handful of specific examples, e.g. that the effect of SNPs in ANKH on calcium are mediated by citrate. Such additional data is necessary because, as the authors' point out, while we have thousands of SNPs with significant impact on phenotypes of interest, we often don't know at all the mechanism, given that the majority of significant SNPs found through GWAS are in non-coding (and often intergenic) regions.

      This paper shows how one can mine large existing datasets to better estimate the cellular mechanism of significant, causal SNPs, and the authors have proven that by providing insight into the links between a couple of genes (e.g. FADS2, TMEM258) and metabolite QTLs and consequent phenotypes. There is definitely a need and utility for this, given how few significant SNPs (and even fewer recently-discovered ones) hit parts of the DNA where the causal mechanism is immediately obvious and easily testable through traditional molecular approaches.

      I find the paper interesting and it provides useful insight into a still relatively new approach. However, I would be interested in knowing how well this approach scales to the general genetics community: would this method work with a much smaller N (e.g. n = 500)? Being able to make new insights using cohorts of nearly 10,000 patients is great, but the vast majority of molecular studies are at least an order of magnitude smaller. While sequencing and mass spectrometry are becoming exponentially cheaper, the issue of sample size is likely to remain for the foreseeable future due to the challenges and expenses of the initial sample collection.

    1. Reviewer #1 (Public Review):

      The paper studied spatial-temporal characteristics of dominant T cell clones in juvenile idiopathic arthritis. The authors found that the composition and functional characteristics of immune infiltrates are strikingly similar between joints within one patient, and observed a strong overlap between dominant T cell clones, especially Treg. Moreover, in localized autoimmune disease there is auto-antigen driven expansion of both T effector and Treg clones, that are highly persistent and are (re)circulating.

    1. Reviewer #1 (Public Review):

      Tafenoquine is an important 8-aminoquinoline antimalarial, mostly aimed at the management of Plasmodium vivax malaria. Through the retrospective analysis of several previously performed efficacy trials, the authors aimed to better understand the drugs mechanism of action, while exploring the possibility of improved efficacy through dose increment.

      Strengths: robust analysis approaches unlocked three main messages with the potential of improving the clinical practice:<br /> i. P. vivax recurrency is positively associated with tafenoquine terminal half-life and D7 methemoglobin levels.<br /> ii. The methemoglobin levels support the current view that tafenoquine, acts through its metabolites, similar to what is believed for primaquine.<br /> ii. Most importantly, the therapeutic window of tafenoquine is wider than previously considered, allowing the suggestion of a significant increase in dosing, from 300 mg to 450 mg, leading to significantly increased efficacy.

      Weaknesses: being a retrospective analysis, the work is limited to the available data. In particular, and as referred by the authors, no drug levels are reported. Additionally, there are some aspects that in my view need more detailed analysis and discussion, in particular, what seems to be a lack of exploration as to the importance (or lack of it) of the patient CYP2D6 status in Tafenoquine T1/2, methemoglobin levels, and overall efficacy. These mild weaknesses do not change the overall conclusions of the study.

    1. Reviewer #1 (Public Review):

      This paper is a continuation of other research by this group and represents another step back in time for peptide preservation in eggshells. It is exciting to see Miocene age peptides and that they overlap so completely with both extant ostrich struthiocalcin as well as the previously described Pliocene peptides. The biggest weakness is the lack of tables showing both the de novo peptides as well as those detected by database searching.

    1. Reviewer #1 (Public Review):

      The manuscript by Heckman and Doe describes a nice set of experiments that extend previous studies of the plasticity in wiring and growth of a sensory axon terminal (Dbd) and its connection to a partner interneuron (A08a) in Drosophila embryonic/larval ventral nerve cord. The authors confirm and extend prior studies in the lab that showed misrouting of Dbd axons cause changes in its site of connection on medial versus lateral dendrites of A08a. The authors show using misrouting and ablation of Dbd that the site of axonal innervation plays a role in promoting dendrite outgrowth in that specific domain of the A08a dendritic field, suggesting a contact-dependent dendrite growth mechanism regulates early connections. The authors then describe a second mechanism where activity of the Dbd sensory neuron regulates a separate aspect of early connectivity, whereby reduced activity leads to increase A08a dendrite growth globally and increased activity suppresses overall A08a dendrite growth. This study fits with other work in the field on the role of activity in synaptic wiring while highlighting the opposing roles of contact versus activity in establishing early connection patterns. They also identify a brief developmental window where Dbd ablation causes A08a dendritic undergrowth, suggesting an early critical period for contact-dependent dendritic growth modulation, similar to that observed for activity-dependent plasticity. Overall, this is a nice study that provides important advances in our understanding of the plasticity of early neuronal wiring.

    1. Among the most famous of these victories was the Bolivian uprising against the Bechtel Corporation, the fifth largest privately-owned company in the US,[28] which had taken over the Cochabamba region’s water supply in 1999. The company raised rates by 300 percent,[29]cutting off service to people who could no longer afford water—and even prevented residents from collecting rainwater unless they obtained a legal permit
    1. Proponents of market environmentalism in the water sector argue that water is an increasingly scarce resource, which must be priced at full economic and environmental cost if it is to be allocated to its highest-value uses, and managed profitably by private companies whose accountability to customers and shareholders is more direct and effective than attenuated political accountability exercised by citizens via political representatives

      Water is seen as an economic resource and because of its scarcity is considered to be priced at full economic and environmental cost. Additionally, it is considered that it should be set aside for its highest valued users and managed by private companies for profit.

    2. over 20% the world's population was without access to sufficient supplies of potable water necessary for basic daily needs

      Claim 1: Water is no longer a human right or those without it would be able to appeal for access to water. Evidence for Claim 1

    1. Reviewer #1 (Public Review):

      This study examines how the COVID-19 pandemic impacted cervical cancer screening participation to invitations sent through the organized cervical cancer screening program of Denmark. I think the results are particularly enlightening in the context of pandemic recovery, as they show that while the short-term participation (90 days) dropped due to public health messaging emphasizing staying at home, the long-term participation (365 days) did not drop; this suggests that women did not completely miss the opportunity to screen during the pandemic, but simply postponed their screening to a later point in time. I think this has implications, especially for modeling the impact of the pandemic on cancer incidence, as many screening models have made the assumption that screenings missed during the pandemic would not be "caught up" later leading to higher cancer incidence in the long term; however, this study suggests that this is not the case and that there is a natural 'catch up' of screening that occurs over time. This is reassuring, as a short delay in cervical cancer screening would not be expected to lead to overly important long-term negative health outcomes.

      Particular strengths of this study include the population-based registry covering the whole target population, and the ability to link the data to socioeconomic variables of interest to examine whether there were particular groups of women which were more impacted than others. The models also accounted for seasonal and long-term trends in cancer screening participation, which bolsters the confidence that their results are not the result of trends in cervical screening participation over time and are most likely attributable to the COVID-19 pandemic. However, as the statistical methods do not include an interaction test for the overall effect of each socioeconomic variable, it is not clear whether the differences that are observed between women by age and socioeconomic status are significant.

    1. Reviewer #1 (Public Review):

      This study explores the mechanisms responsible for reduced steroidogenesis of adrenocortical cells in a mouse model of systemic inflammation induced by LPS administration. Working from RNA and protein profiling data sets in adrenocortical tissue from LPS-treated mice they report that LPS perturbs the TCA cycle at the level of succinate dehydrogenase B (SDHB) impairing oxidative phosphorylation. Additional studies indicate these events are coupled to increased IL-1β levels which inhibit SDHB expression through DNA methyltransferase-dependent DNA methylation of the SDHB promoter.

      In general, these are interesting studies with some novel implications. I do, however, have concerns with some of the author's rather broad conclusions given the limitations of their experimental approach. The paper could be improved by addressing the following points:

      1. The limitations of using LPS as the model for systemic inflammation need to be explicitly described.<br /> 2. The initial in vivo findings, which support the proposed metabolic perturbation, are based on descriptive profiling data obtained at one time point following a single dose of LPS. The author's conclusion that the ultimate transcriptional pathway identified hinges critically on knowledge of the time course of this effect following LPS, which is not adequately addressed in the paper. How was this time and dose of LPS established and are there data from different dose and time points?<br /> 3. Related to the point above, the authors data supporting a break in the TCA cycle would be strengthened direct biochemical assessment (metabolic flux analysis) of step kin the TCA cycle process impacted.<br /> 4. The proposed connection of DNMT and IL1 signaling to systemic inflammation and reduced steriodogenesis could be more firmly established by additional studies in adrenal cortical cells lacking these genes.

    1. Reviewer #1 (Public Review):

      Neverov and colleagues present a large-scale computational investigation of epistatic interactions between substitutions in the spike protein. The analysis is based on an improved version of their previous approach that has been applied to other organisms to the Influenza A virus. They find several sets of interacting sites that tend to change in concert.

      The approach is sensible and the work seems well executed. A systematic investigation of epistatic interactions is important to better understand the constraints and drivers of future SC2 evolution. This work is hence an important contribution to the field and a nice complement to experimental work by Jesse Bloom's group and others.

      The authors uncover several groups of residues that seem to change in concert. The identified groups make sense, but further validation and comparison with experimental or other computational approaches would strengthen the conclusions.

    1. Reviewer #1 (Public Review):

      Summary:

      It is widely known that lesioning the vHP produces anxiogenic effects, and cells in the vHP increase their firing rates in the anxiogenic location. This paper aims to investigate the neural dynamics of the vHP when a non-anxiogenic location changes to an anxiogenic one during spatial navigation. For testing, the authors removed half of the side walls of the elevated linear maze or track in the middle of the session. They reported that cells in the vHP remapped and overrepresented anxiogenic places as the walls were removed. Also, the authors claim that single-cell activities recorded before entering the open portion of the track could be used to predict how far the rat would explore along the open segment of the track.

      Strength and weakness:

      The experimental paradigm was well-designed to examine the main research question. It is novel in that the authors recorded single cells electrophysiologically in the vHP, as this has been done only in very few studies. However, in the current version of the manuscript, the main argument (tied to Figure 5) is not supported by detailed neural and behavioral data. Specifically, the authors did not provide the basic firing properties of the electrophysiological data to verify the quality of single-cell recording data. Also, they did not compare the velocity and position data before entering the open arm between the proximal and distal exploration. Thus, it is hard to reject the alternative hypothesis that the difference in neural activities between the exploration types stems from behavioral differences, not necessarily based on prediction signals.

      Significance of the work:

      This study should contribute to the single-cell-level understanding of the vHP with only very few experimental data available in the literature on the topic. Since some of the previous studies that claimed to record the ventral hippocampus actually targeted the intermediate portion of the hippocampus, this study would set a new standard for investigating the true ventral hippocampus.

    1. Reviewer #1 (Public Review):

      The authors set out to develop an in vitro model of multiple species representing diversity in the CF airway as a platform for a range of studies on why polymicrobial communities resist therapy. The rationale for their design is sound and the methods appear justifiable and reproducible. The major strength of this work is in producing a method for a range of future work, ideally for multiple groups in the field. The primary findings are interesting but not groundbreaking. One weakness in the method of reporting interspecies interactions and another in evaluating alternative causes of lasR advantages present opportunities for a stronger research contribution beyond this terrific method.

    1. Reviewer #1 (Public Review):

      The authors sought to explore the brain age paradigm in the early stages of Alzheimer's disease, focusing on the combination of different MRI modalities (brain structure derived from T1-weighted MRI and functional connectivity derived from resting state fMRI). Their goal was to understand how different unimodal brain ages and a combined multi-modal brain age related to risk factors related to Alzheimer's disease, namely hippocampal volume, cognitive performance, amyloid or tau positivity from PET scans or CSF data and neurofilaments. As part of this, they aimed to ascertain which brain age models performed more accurately.

      The major strength of the methods is the novel combination of different MRI modalities using Gaussian Processes and stacking to predict brain age. Another strength is the use of multiple data sources for both model training and testing, reducing the reliance on a single site and decreasing the likelihood of overfitting, which should improve generalisability. A weakness is the poor fit of the functional connectivity model to the data, whereby the vast majority of test participants were shown to have younger appearing brains, even those with cognitive impairment. This indicates that an alternative fMRI processing pipeline could have been beneficial, however, no experimentation on this important facet of the analysis was included. Another weakness is the relatively limited sample size compared too much of the brain age literature and the failure to report the R^2 metric, which is important for the comparison of this study with previously published reports. Potentially, more accurate models would have led to clearer results, as there are a number of borderline findings which hinder clear interpretation.

      In general, the study did meet its stated goals and was able to generate a multi-modality brain-age model and this model did show older appearing brains in people with cognitive impairment. This model also showed that people with older appearing brains had poorer cognition, lower hippocampal volume, and greater amyloid deposition. In people who met the criteria for being cognitively impaired, greater tau deposition on PET scans was associated with an older appearing brain. One claim of the study is that the multi-modality brain-age model was more accurate than the brain-volume model, however, it is unclear from the report whether appropriate statistics were used for this. The authors need to clarify exactly what procedure they undertook to compare the models, as they potentially employed an erroneous method (determining statistical significance based on the number of bootstraps instead of the number of observations) which may have led them to mistakenly claim better performance.

      Given the relatively poor or equivocal performance of the brain age models and the relatively small sample sizes available, it is not clear that the modelling or dataset will have a big impact on the field. More accurate modelling methods are openly available, as are larger datasets. Nevertheless, the study is well-motivated and scientifically rigorous, so the results themselves are informative regarding the interrelationships of key Alzheimer's biomarkers and risk factors.

    1. Reviewer #1 (Public Review):

      This is an important, well-written and easily comprehended quantitative imaging study that analyzes the motion of endo-lysosomal compartments within axons in vivo using simultaneous multiphoton imaging in the mammalian brain. The simultaneous dual two-photon imaging is well-executed and represents a substantive advance in a field that relies heavily on in vitro neuronal culture preparations. This work opens the door to neurons that have aged appropriately and done so in the context of normal synaptic and neuromodulatory input, without an excess of added factors that occurs with in vitro cell culture. The authors solve an issue of cell polarity, providing strong support for their ability to determine directional movement (anterograde versus retrograde). In principle, this could become a generalized approach, opening this type of experiment up to other investigators. Finally, interesting differences in motion are observed, including activity-dependent and calcium-dependent changes that differ from measurements made in vitro. This is a significant technical advance with interesting observations that substantively move the field forward.

    1. Reviewer #1 (Public Review):

      The authors develop and freely disseminate the THINGS-data collection, a large-scale dataset incorporating MRI, MEG, eye-tracking, and 4.7 million similarity ratings for 1,854 object concepts. Demonstrating the reliability of their data, the authors replicate nearly a dozen previous neuroimaging papers. This "big data" approach significantly advances our ability to link behavioral measures with neuroimaging at scale, with the potential to spark future insights into how the mind represents objects.

      I thought that the article was well-written, with a sound methodological approach, high-quality results, and well-supported conclusions. I am overall enthusiastic about this work, and I think THINGS will provide an important benchmark for future big data approaches in cognitive and computational neuroscience.

      However, I thought it was also important to articulate more directly the potential insights this dataset can offer to the field. Although the authors mentioned that they "provided five examples for potential research directions", it was not clear to me what these new research directions were, given that the authors entirely describe replications in the results.

    1. Reviewer #1 (Public Review):

      The authors of this paper have used emerging environmental DNA (eDNA) methods to profile depth-biodiversity in two deep ocean trenches.

      Strengths:<br /> Working in deep ocean habitats is challenging and this paper provides data from not one but two deep ocean trenches and provides new perspectives on biodiversity distributions in these habitats. The most interesting finding is that deep ocean habitats appear to contribute much more biodiversity, as measured using relatively novel eDNA techniques than previously thought. The comparison of these two trenches also illustrates the variable nature of these biodiversity patterns and suggests trench-specific features (e.g. unique habitats and/or productivity) influence deep ocean biodiversity.

      Weaknesses:<br /> While eDNA methods are becoming more established, there remains skepticism by many in the scientific community about the origins of the detected DNA (e.g. does it drift in from other areas or water layers?). If these concerns aren't addressed (i.e. by citing supporting literature on the fate of eDNA), the different biodiversity profiles between trenches could possibly be explained by differing oceanography. There is also some important methodological information that is missing from this manuscript. For example, sampling volumes will affect the amount of biodiversity detected, but it is not clear if sample volumes are consistent across depths and study areas. It was also not indicated whether field controls (blanks) were taken to assess the potential contamination of samples. Lastly, the literature in the eDNA field is progressing rapidly and there are some missing papers (e.g Thomsen et al. 2016, Canals et al. 2021, McClenaghan et al. 2020, Govindarajan et al. 2021, etc.) that are relevant to the technique used in this manuscript and the habitat studied.

    1. Reviewer #1 (Public Review):

      This group previously demonstrated that trisomy 21 causes an increase in PCNT levels, and this increase leads to pericentrosomal crowding and inhibition of ciliogenesis in fibroblasts. The authors here use trisomy and tetrasomy 21 retinal pigment epithelium cells generated by microcell-mediated chromosome transfer (MMCT) and previously generated mouse models of human trisomy 21. The well-quantified data and well-reasoned paper compellingly demonstrate that modestly increased PCNT levels can attenuate ciliogenesis and may result in trisomy 21-associated phenotypes such as cerebellar growth defects.

    1. Reviewer #1 (Public Review):

      The authors describe a feeding system for killifish that allows high precision control of feeding amount and schedule on a per-tank basis. The system permits automation of this task using open-source and affordable components and software. Due to this emphasis, the system appears amenable to manufacture by individual research groups and the approach appears very scalable (although more detailed build, programming and assembly instructions and videos might be useful for groups with little experience with microcontrollers and manufacturing). An exciting aspect of the system is the possibility to modify the system for different purposes. For example, it might be possible to reduce the minimum feeding amount, thereby allowing more fine grained exploration of effects related to feeding shedule. I am very enthusiastic about the open-source "maker" aspects of this work.

      The authors next explore two interesting applications of the system. First, they show that precise control of food allows automated investigation of lifespan extension under calorie restriction (CR) conditions. This is an important use case for a system of this type and showing that it is fit for this application is important.

      Secondly, the authors show an exciting modification of the system that involves only addition of a simple red light LED. This modification allows use of the system in a associative learning / conditioning paradigm.

      Finally, they show that there is an age-dependent decline in learning as evaluated by this conditioning paradigm. I am very enthusiastic about this additional function and, again, this example demonstrates the flexibly and open nature of the technology, suggesting that others can likely modify and expand the system to suite their own questions and applications. In summary, I am enthusiastic about the technology described and about the approach by which the system was developed.

      However, at the current stage, the biological applications are essentially validation experiments - e.g. showing that CR can be implemented and that the system can be used for learning and memory experiments. Neither of these aspects is pursued beyond the basic validation experiments (showing that lifespan extension can be achieved and that there is age-dependent decline in associative learning).

    1. Reviewer #1 (Public Review):

      Leukemic cells are known to remodel bone marrow niche to promote their expansion and to suppress normal hematopoiesis. However, molecular mechanisms remain largely unknown. In this manuscript, authors developed new experimental models in mice to address this issue, using mouse BCR-ABL-driven ALL cells marked with YFP, or DOX-inducible MLL-AF9 AML cells. After transplantation of either of these cells, authors discovered suppression of host hematopoiesis. Using these systems, authors tested their hypothesis on lymphotoxin receptor-mediated interaction of the leukemic cells and stroma cells.

      The main conclusions here are: 1) lymphotoxin signaling through its receptor mediates IL7 down regulation and alters gene expression related to inflammation etc. in stroma cells, 2) IL7 down regulation leads to reduction in B lymphoid cells but not myeloid cells, 3) lymphotoxin expression in leukemic cells is induced by DNA damage response, and 4) CXCR4, which is known to be induced in B cells in response to stroma cells, collaborates with DNA damage in induction of lymphotoxin in leukemic cells. Taken together, authors suggest that a positive feedback loop of leukemic cells and stroma cells for leukemic cell proliferation and normal hematopoietic suppression, involving lymphotoxin and CXCR4 in leukemic cells and lymphotoxin receptor in stroma cells. Generally, these conclusions and the model of the positive feedback regulation are supported, to a reasonable level, by the experimental results provided in the manuscript. However, some of the results show small effects of manipulations, leaving the pathological significance of the feedback model as a future issue.

    1. Reviewer #1 (Public Review):

      Polarization in cells and organs is often dictated by opposing polarity domains. In grass subsidiary cells, several proteins (including PAN1) were previously found to polarize in a discrete patch prior to asymmetric division. Zhang et al. identify POLAR via transcriptional profiling of Bdmute, a mutant that lacks subsidiary cells The authors effectively show that Bdpolar mutants have defective subsidiary cells. A distinctive and exciting localization pattern of POLAR is demonstrated, which is opposite to PAN1. This localization pattern is further contextualized by showing that PAN1 and MUTE are both required for POLAR's distinctive localization; however, PAN1 polarization is unaffected in both polar and mute. The integration of MUTE, POLAR, and PAN1 is particularly important as it integrates how polarity proteins and fate factors interact with each other.

      Bdpolar mutants have defects in subsidiary cells that lead to defects in stomatal function. The authors carefully and quantitatively compare the phenotypes of pan1 and polar and conclude distinct roles for the two proteins based on differences in phenotypes including nuclear polarization, division site specification, and repeated rounds of cell division. The discovery and localization of POLAR are very exciting, but the comparison between single alleles of pan1 and polar and the extrapolation requires scrutiny. In particular, the data on division site specification in pan1 seem inconsistent with the % defective subsidiary cells and nuclear migration defects. However, these are addressable and given the exciting nature of the localization and pathway determination, the paper's impact stands.

    1. Reviewer #1 (Public Review):

      The research investigates the genetic basis for resistance to high CO2 levels in the human pathogenic fungus Cryptococcus neoformans. Screening collections of over 5,000 gene deletion strains revealed 96 with impaired growth, including a set of genes all related to the same RAM signaling pathway. Further genetic dissection was able compellingly to place where this pathway lies relative to upstream inputs and through the isolation of suppressor mutants as potential downstream targets of the pathway. Given the high levels of CO2 encountered by fungi in the human host, this work may provide new directions for the control of disseminated fungal disease.

      The research presents both strengths and weaknesses.

      Strengths include:

      (1) One of the largest scale analyses of genes involved in growth under high CO2 concentrations in a fungus, revealing a set of just under 100 mutants with impaired growth.<br /> (2) Elegant genetic epistasis analysis to show where different components fit within a pathway of transmission of CO2 exposure. For example, over expression of one of the kinases, Cbk1, can overcome the CO2-sensitivity of mutations in the CDC24 or CNA1 genes (but not in the reciprocal overexpression direction).<br /> (3) Isolation of suppressor mutations in the cbk1 background, now able to grow at high CO2 levels, was able to lead to the identification of two genes. Follow up characterization, which included examining in vitro phenotypes, gene expression analysis, and impact during mouse infection was able to reveal that the two suppressors restore a subset of the phenotypes impacted by mutation of CBK1. Indeed, one conclusion from this careful work is that the reduced virulence of the cbk1 mutant is not due to its sensitivity to high levels of CO2, perhaps an unexpected finding given the original goals of the study towards linking CO2 sensitivity with decreased virulence.

      Weaknesses include:

      (1) What is the rationale for examining gene expression using the NanoString technology of 118 genes rather than a more genome-wide approach such as RNA-sequencing?<br /> (2) Without additional species examined, some of the conclusions about differences in impact between ascomycetes and basidiomycetes might instead reflect differences between species. For example, RAM mutants in other strains of C. neoformans do not exhibit so strong a temperature sensitive phenotype. Or to extend the comparison further, one might assume given the use of CO2 for Drosophila manipulations that the RAM pathway components in an insect would not be required for surviving high CO2.<br /> (3) Given the relative ease of generate progeny of this species, it would have been informative to explore if the suppressors of cbk1 also suppressed the loss of genes like CDC24, CNA1, etc, equivalent to the experiment performed of overexpression of CBK1 in those backgrounds.

    1. Reviewer #1 (Public Review):

      This paper makes an important contribution to the current debate on whether the diversity of a microbial community has a positive or negative effect on its own diversity at a later time point. In my view, the main contribution is linking the diversity-begets-diversity patterns, already observed by the same authors and others, to genomic signatures of gene loss that would be expected from the Black Queen Hypothesis, establishing an eco-evolutionary link. In addition, they test this hypothesis at a more fine-grained scale (strain-level variation and SNP) and do so in human microbiome data, which adds relevance from the biomedical standpoint. The paper is a well-written and rigorous analysis using state-of-the-art methods, and the results suggest multiple new experiments and testable hypotheses (see below), which is a very valuable contribution.

      That being said, I do have some concerns that I believe should be addressed. First of all, I am wondering whether gene loss could also occur because of environmental selection that is independent of other organisms or the diversity of the community. An alternative hypothesis to the Black Queen is that there might have been a migration of new species from outside and then loss of genes could have occurred because of the nature of the abiotic environment in the new host, without relationship to the community diversity. Telling the difference between these two hypotheses is hard and would require extensive additional experiments, which I don't think is necessary. But I do think the authors should acknowledge and discuss this alternative possibility and adjust the wording of their claims accordingly.

      Another issue is that gene loss is happening in some of the most abundant species in the gut. Under Black Queen though, we would expect these species to be most likely "donors" in cross-feeding interactions. Authors should also discuss the implications, limitations, and possible alternative hypotheses of this result, which I think also stimulates future work and experiments.

      Regarding Figure 5B, there is a couple of questions I believe the authors should clarify. First, How is it possible that many species have close to 0 pathways? Second, besides the overall negative correlation, the data shows some very conspicuous regularities, e.g. many different "lines" of points with identical linear negative slope but different intercept. My guess is that this is due to some constraints in the pathway detection methods, but I struggle to understand it. I think the authors should discuss these patterns more in detail.

      Finally, I also have some conceptual concerns regarding the genomic analysis. Namely, genes can be used for biosynthesis of e.g. building blocks, but also for consumption of nutrients. Under the Black Queen Hypothesis, we would expect the adaptive loss of biosynthetic genes, as those nutrients become provided by the community. However, for catabolic genes or pathways, I would expect the opposite pattern, i.e. the gain of catabolic genes that would allow taking advantage of a more rich environment resulting from a more diverse community (or at least, the absence of pathway loss). These two opposing forces for catabolic and biosynthetic genes/pathways might obscure the trends if all genes are pooled together for the analysis. I believe this can be easily checked with the data the authors already have, and could allow the authors to discuss more in detail the functional implications of the trends they see and possibly even make a stronger case for their claims.

    1. Reviewer #1 (Public Review):

      This is an interesting paper that presents a novel idea for the identification of risk factors amongst highly correlated traits in a Mendelian randomization paradigm - a previous investigation (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8438050/) has considered PCA, but not sparse PCA. There are clear conceptual reasons why sparse PCA may be an improvement, as detailed in this paper. Overall, the paper does a good job in terms of motivating this work and comparing the methods. A large chunk of the motivation for the method is conceptual (rather than empirical), and it's unlikely that any method would outperform others in all circumstances, but the authors do a good job of illustrating differences and giving a clear and qualified recommendation.

    1. Reviewer #1 (Public Review):

      There were two parts to this paper. The first was to build a network model with parameters carefully adjusted to match those seen in the turtle cortex. The second was to simulate the circuit, and show that it could produce reasonably repeatable patterns of activity in response to a single, externally added, spike.

      As a model of the turtle cortex, the paper was pretty convincing. And the explanation for the repeatable patterns of activity - a small number of very strong connections and a very low background firing rate - seemed eminently reasonable. This paper should serve as a very good starting point for understanding computing in the turtle cortex.

      However, average firing rates in the turtle are extremely low - 0.1 Hz, at least in these simulations. Their model is unlikely, therefore, to account for activity in the mammalian cortex, which exhibits a much higher background firing rate, and for which there's not a lot of evidence for the extremely strong connections seen in the turtle.

    1. Reviewer #1 (Public Review):

      This paper describes detailed experiments to characterize the morphology and deformability, of red blood cells (RBCs) from COVID patients as compared to healthy individuals. Deformability is characterized by the visualization of cell shapes during flow in a microfluidic channel at high strain rates. One important feature of the study is that it considers the changes in patient RBCs when placed in healthy plasma and vice versa. An important observation is that the changes to RBCs properties appear, from this report, to be reversible - diseased cells revert to normal morphology and deformability upon immersion in healthy plasma. It also reports metabolics and proteomics analyses to shed light on the connections between the biochemical environment and RBC properties. One important question with regard to the changes in COVID-RBC properties with respect to plasma composition is whether the effect is simply due to dilution - are the factors responsible for the pathological morphology just diluted away when the cells are immersed in plasma that does not contain them? The studies are performed at very low hematocrit, so the composition equilibrium established here will not correspond to physiological conditions. This issue needs further discussion.

    1. Reviewer #1 (Public Review):

      This paper estimates the selective effects of loss-of-function mutations in each gene, ultimately providing an estimate of the overall distribution of fitness effects, and point estimates for each gene. Unlike some measures of intolerance such as pLI, the parameter the authors estimate (effectively the compound parameter hs) is interpretable in terms of evolutionary fitness. The most comparable analysis is by Weghorn et al (2019) which estimates the same parameter, but on a smaller sample and using a different approach.

      The point estimates will be broadly useful for future analyses, and the overall distribution is an interesting result. The enrichment in various disease cohorts is unexpected but nice to demonstrate. Overall, I found the approach to be elegant and it has the nice property that it can be easily generalized to more complicated models. The data cleaning and filtering is quite extensive but all seems well done and appropriate. Qualitatively, the results clearly make a lot of sense (Figure 3 is an excellent figure) My only major questions are around how quantitatively robust this analysis is to the choice of parameters and hyperparameters including priors, mutation rates, and demography. I don't think that extensive work is required, but it would be helpful to see some quantification of this uncertainty.

    1. Reviewer #1 (Public Review):

      The authors note contradictory clinical data on the effects of functional FAAH mutations on body weight in clinical samples. They aim to resolve this issue via animal modes and genetic approaches combined with endocrine manipulations to vary "context". Major strengths are comprehensive evaluation of FAAH variant in several models of neuroendocrine changes in body weight (CORT, leptin, gherlin) and provide some mechanistic insight at the signal transduction level. Localization of FAAH modulation to AGRP neurons is a strength. Weaknesses include lack of cellular mechanisms, i.e. how AEA release from AGRP neurons affects ongoing cellular/synaptic activity to regulate behavioral/physiological phenotypes. The work is impactful as it potentially reconciles contradictory clinical data, is comprehensive and rigorous in many ways. These data will provide insight into how FAAH activity regulates body weight in the context of distinct hormonal signals and will likely have a major impact on the field.

    1. Reviewer #1 (Public Review):

      When we tilt our heads, we do not perceive objects to be tilted or rotated. In this study, the authors investigate the underlying neural underpinnings by characterizing how neurons in monkey IT respond to objects when the entire body is tilted. They performed two experiments. In the first experiment, the authors record single neuron responses to objects rotating in the image plane, under two conditions - when the animals were tilted +20{degree sign} or -20{degree sign} relative to the gravitational vertical. Their main finding is that neural tuning curves for object orientation were highly correlated under these conditions. This high correlation is interpreted by the authors as indicative of encoding of object orientations relative to an absolute gravitational reference frame. To control for the possibility that the whole-body tilt could have induced compensatory torsional rotations of the eyes, the authors estimated the eye torsional rotation between the {plus minus}20{degree sign} whole-body tilt to be only {plus minus}6{degree sign}. In the second experiment, the authors recorded neural responses to objects rotated in the image plane with no whole-body tilt but with a visual horizon that could be tilted by the same {plus minus}20{degree sign} relative to the gravitational vertical. Here too they find many neurons whose tuning curves were correlated between the two horizon tilt conditions. Based on these results, the authors argue that IT neurons represent objects relative to the gravitational or absolute vertical.

      The question of whether the visual system encodes objects relative to the gravitational vertical is an interesting and basic one, and I commend the authors for attempting this question through systematic testing of object selectivity under conditions of whole-body tilt. However, I found this manuscript extremely difficult to read, with important analyses and controls described in a very cursory fashion. I also have several major concerns about these results.

      First, the high tuning correlation in the {plus minus}20{degree sign} whole-body tilt conditions could also occur if IT neurons encoded object orientation relative to other fixed contextual cues in the surrounding, such as the frame of the computer monitor. The authors ideally should have some experiment or analysis to address this potential confound, or else acknowledge that their findings can also be interpreted as the encoding of object orientation relative to contextual cues, which would dilute their overall conclusions.

      Second, I do not fully understand torsional eye movements myself, but it is not clear to me whether this is a fixed or dynamic compensation. For instance, have the authors measured torsional eye rotations on every trial? Is it fixed always at {plus minus}6{degree sign} or does it change from trial to trial? If it changes, then could the high tuning correlation between the whole-body rotations be simply driven by trials in which the eyes compensated more? The authors must provide more data or analyses to address this important control.

      Third, I find that when the objects were presented against a visual horizon, different object features are occluded at each orientation. This could reduce the correlation between the neural response in the retinal reference frame, thereby biasing all results away from purely retinal encoding. The authors should address this either through additional analyses or acknowledge this issue appropriately throughout.

    1. Reviewer #1 (Public Review):

      This is a brief set of experiments that tells a nice story that is relevant to a very important area of biology, namely senescence. The authors identify a role for lncRNA H19 in senescence and delve into the upstream and downstream factors that could describe the phenomenon. They identify CTCF and p53 as upstream regulators of H19 in senescing cells and propose that sponging of let-7 could be a contributing factor to H19's effects via altered regulation of EZH2.

      The work is backed up by strong data in cell models. However, the work could benefit from additional mechanistic data to support the most important conclusions. For example, does H19 sponge let-7 in these cells? What are the relative levels of expression of H19 compared to let-7 in these cells? Is the let-7 binding site on H19 required for the effects of H19? And does let-7 directly regulate EZH2 in these cells? Can a direct role for H19 in affecting EZH2 be ruled out in these cells?

    1. Reviewer #1 (Public Review):

      In the work by Van Eyndhoven et al., the authors aim to determine if the cell state present in the cells that first produce Type I Interferon (IFN-I, an antiviral cytokine) is stochastically regulated or may be epigenetically inheritable. This work builds from previous studies demonstrating that IFN-I responses occur in two waves: a small proportion of early responding "precocious" cells which induce population-wide responses through autocrine and paracrine signaling. The authors contextualize their study well within the literature, and discuss the hypotheses of stochasticity or determinism driving early responding cell fate. Within this context, the authors set out to characterize and model the nature of these "first responder" cells during IFN-I antiviral signaling. Developing a quantitative imaging approach to measure IRF7 translocation, the authors measure the proportion of first responder cells as defined by higher ratios of nuclear/cytosolic IRF7 expression. Transfection of Poly(I:C) induces IFN-I signaling and leads to ~2% first responders, in line with previously published work. The authors then show that responder frequencies increase following treatment with a DNA methyltransferase inhibitor, suggesting a relationship between epigenetic regulation and responder potential. To test the hypothesis that the first responder cell state occurs stochastically, the authors adapted the Luria-Delbruck fluctuation test by evaluating responder frequency as a function of cell division or generation. First witnessing high variability of responder frequencies using limiting dilution clonal expansion followed by low stable frequencies after 100 divisions (similar to regular cultures), the authors suggest that the first responder state may be partially heritable and develop a mathematical model of transient heritability. Finally, to assess whether cell density and quorum sensing contribute to this transient heritability, cells plated at different densities were interrogated for responder frequencies after a fixed number of divisions; only low density seeding led to high and variable responder frequencies.

      The interrogation of IFN-I early responding cells by Van Eyndhoven et al. is well executed and supports the claim that first responder events are non-stochastic. However, the use of transgenic reporter cells in vitro may limit the findings reported in the manuscript to this system, and awaits further experimentation to assess the generalizability of these findings to overall cellular decision-making during inflammatory responses. Identifying the mechanisms responsible for transient heritability and the density-dependent regulation will be of high interest.

      1) Context and definitions for stochasticity and heritability: The authors provide well-referenced introductions and explanations throughout the manuscript. However, key understanding of concepts for their central hypothesis on transient heritability are not shared until well into the results sections (Lines 215-227), leaving the introduction somewhat unclear on the authors thinking and motivation. The manuscript would benefit by including clear definitions of "stochastic", "transiently heritable", and "heritable" and their relationships to "intrinsic" and "deterministic" in the introduction.

      2) Generalizability of findings to other cell types, systems, and triggers: The cell line and Poly(I:C) delivery method used by the authors lacks sufficient characterization to extend the conclusions derived from its use. Notably, the NIH3T3-IRF7-CFP cell line expresses IRF7 constitutively and thus may only be a good model for cells with similar expression levels; many primary cells only express IRF7 at low levels or not at all until stimulated (PMID: 2140621). The conclusions would be greatly strengthened by demonstrating similar first responder dynamics/heritability in other cell types. The experiments measuring the efficiency of Poly(I:C) delivery by transfection lack sufficient resolution to determine if the Poly(I:C) is intracellular or membrane bound. IFN-I response kinetics, and potentially quality, would likely be distinct between cytosolic and endosomal sensing and may impact the likelihood of becoming a first responder.

      3) Epigenetic regulation of transient heritability: To test the contribution of epigenetic regulation on first responder fate, the authors treat their cells with DNMTi. While treatment with this drug does increase the proportion of first responder cells, the authors don't provide evidence that the mechanism of action is mediated by inhibiting DNA methylation. This is further confounded by the reduced responder frequencies in DNMTi treated cells transduced with Poly(I:C) (Fig 4g). The authors offer an explanation for this observation, but their reported data (Fig 4h) doesn't measure whether DNMTi, leads to latent retrovirus activation, broader demethylation, or a combination of the two.

      4) Temporal experimental data to validate and extend transient heritability and quorum sensing: Developing a model for cellular-decision making during early IFN-I responses, the authors formalize and test the hypothesis of transient heritability. While the data largely fit the model proposed (Fig 6D-F), the reported data points lack sufficient temporal resolution to validate the model during the earlier and more variable generations. Given that by generation 9 variability in first responder frequency has almost stabilized, there is only one data point (generation 6) to evaluate the fit of the ODE described. More densely sampled data points below generation 10 are necessary to validate the model. Moreover, a discussion of Kon calculation/observation, meaning, and validation is missing. To partially test their claim that Kon is a function of density (i.e., quorum sensing), the authors plate cells at different densities and measure the responder frequency at generation 6. This analysis lacks contextualization of other autocrine and paracrine signals potentially impacting IFN-I response. Moreover, these signals will be diverse in different cell types and could impact Kon and/or the overall model.

    1. Reviewer #1 (Public Review):

      The study by Lehmann et al. reports novel structures of the human ferroportin (SLC40A1), which is responsible for iron transport in the body. Specifically, ferroportin controls the plasma concentration of iron by transporting Fe2+ out of the cell. To regulate plasma iron concentrations, the liver releases hepcidin, a peptide-based hormone that inhibits ferroportin activity. Specific inhibitors of ferroportin are being developed to treat thalassemia and sickle cell disease, which are diseases that result in reduced red blood cell function.

      The present study reports the structure of human ferroportin in complex with one such inhibitor, vamifeport, which is currently in clinical trials for sickle cell disease. The authors use their structures to suggest a mechanism for vamifeport binding to ferroportin and support the structural data with in vitro binding assays to study the specific interactions made in the binding site. In addition, one of the structures obtained was a novel protein conformation, an occluded state. This is the first occluded state observed for ferroportin, enabling the authors to discuss the implications for understanding the transport mechanism. However, this appears to have resulted in a slightly confusing analysis.

      Overall the study is well presented, although in several places appears overly wordy and might benefit from being edited to focus on the main points the authors wish to highlight. For example, the title focuses on the new insights gained from the vamifeport complex. Yet, the discussion section focuses almost entirely on the transport mechanism, with little additional analysis of the mechanism of vamifeport inhibition. In my view, the paper suffers from this disconnect, as the functional data support the vamifeport structure, not the transport mechanism. Yet, the discussion focuses heavily on the transport mechanism, with little reference to the results. Rather, the discussion relies on an in-depth understanding of secondary active transport literature (MFS, NRAMP, etc.).

      The data is high quality, and the conclusions drawn about the orientation of the drug in the binding site are sound. This study represents an important advance in understanding iron homeostasis in the human body and current methods to modulate iron transport to treat human disease.

    1. Reviewer #1 (Public Review):

      In this manuscript, Vandrey et al characterize axonal projections from fan cells in the lateral entorhinal cortex (LEC) to the medial entorhinal cortex (MEC). Their findings are important and the manuscript is well-written.

    1. Reviewer #1 (Public Review):

      Andreyeva et al. developed a novel purification/mass spec approach to identify SuUR-associated proteins. From this biochemical tour de force, they identify a complex consisting of the insulator-associated protein Mod(Mdg4) and SuUR that they term, SUMM4. They show that this complex (at least SuUR) has ATPase activity, which is an exciting result was no known biochemical activity associated with SuUR. Given SuUR's function in the under-replication of Drosophila salivary glands, the authors show that SuUR and Mod(Mdg4) at least partially localize on polytene chromosomes and that SuUR displays at least a partial dependence on Mod(Mdg4) for localization to IH, but not PH regions. Finally, using two independent genetic reporters, they show that SuUR itself has an insulator function, which is a new function for SuUR and exciting as it is likely a diploid cell-specific function for SuUR. The authors then attempt to show the Mod(Mdg4) functions in under-replication. Unfortunately, under-replication is minimally, if at all, changed in the Mod(Mdg4) mutant. While the authors bring up several possible scenarios of why this could be, it is still uncertain whether Mod(Mdg4) has a direct effect on under-replication.

      Strengths:<br /> The authors developed a very useful strategy to identify protein interactions through multiple purification steps using mass spectrometry. This approach can be applied to different systems and will be generally useful to the community. Through this approach, they provide very compelling data that SuUR and Mod(Mdg4) form a complex. Furthermore, the experiments all have been rigorously performed and the data is of high quality.

      Weaknesses:<br /> The way the paper is written, its main focus is on under-replication. What the authors were not able to conclusively demonstrate is whether Mod(Mdg4) functions in under-replication.

    1. Reviewer #1 (Public Review):

      This is a relatively straightforward manuscript describing an r package that attempts to address issues in color-blindness in the interpretation of multicolor overlapping plots. The demonstration of its usefulness is solid and the findings will be significant in that they should become one of the standards that the scientific community strives to achieve for greater inclusiveness.

    1. Reviewer #1 (Public Review):

      The layered costs and benefits of translational redundancy by Raval et al. aim to investigate the impact of gene copy number redundancy on E. coli fitness, using growth rate in different media as the primary fitness readout. Genes for most tRNAs and the three ribosomal RNAs are present in multiple copies on the E. coli chromosome. The authors ask how alterations in the gene copy number affect the growth rate of E. coli in growth media that support different rates of growth for the wild type.

      While it was shown before that mutants with reduced numbers of ribosomal RNA operons grow at reduced rates in rich medium (LB), this study extends these findings and reaches some important conclusions:

      1) In a poor medium (supporting slow growth rates), the mutants with fewer rRNA operons actually grow faster than the wild type, showing that redundancy comes at a cost.

      2) The same is true for mutants with reduced gene copy number of certain tRNAs and correlates with slower rates of protein synthesis in these mutants.

      3) That rRNA operon gene copy number is more decisive for growth rate than any tRNA gene copy number (>1).

      In addition, measurements of strains with deletions of genes encoding tRNA-modification enzymes that affect tRNA specificity are included. While interesting, no unifying conclusion could be reached on the impact of these mutations on growth rate.

      The well-known "growth law" relationships between growth rate and macromolecular composition (RNA/protein ratio, for example) specifically concern steady-state growth rates. It is concerning that all growth rates in this work were measured on cultures that were only back-diluted 1:100 from overnight LB precultures. That only allows 6-7 doubling times before the preculture OD is reached again. The exponential part of growth would end before that, allowing perhaps only 3-4 generations of growth in the new medium before the growth rate was measured. Thus, the cultures were not in balanced growth ("steady state") when the measurements were made, rather they were presumably in various states of adapting to altered nutrient availability.

      A second concern is the use of the term "tRNA expression levels" in the text in Figure 4. I believe the YAMAT-seq method reports on the fractional contribution of a given tRNA to the total tRNA pool. Thus, since the total tRNA pool is larger in fast-growing cells than in slow-growing cells, a given tRNA may be present at a higher absolute concentration in the fast than in the slow-growing cells but will be reported as "higher in poor" in figure 4, if the given tRNA constitutes a smaller fraction of the total tRNA pool in rich than in poor medium. For this reason, the conclusions regarding the effect of growth medium quality on tRNA levels are not justified.

    1. Reviewer #1 (Public Review):

      In this paper from Geisberg et al., the authors examined cleavage site usage in yeast and human cells that express Pol II mutants with faster or slower elongation rates. The authors focused on two types of alternative cleavage sites, one being multiple sites clustered within a short range (called within cluster sites) and the other being multiple sites that are distant from one another (called between cluster sites). The authors identified polarity site usage of within a cluster in cells expressing mutant Pol II. Slower Pol II leads to more proximal site usage whereas faster Pol II mutant to distal site usage. In contrast, these trends were not observed with sites between clusters. The authors made four conclusions based on these observations. Overall this is a very well-written paper revealing some fundamental features associated with cleavage site choice. Most conclusions are supported by their data. I do, however, have some concerns about their between-cluster analysis.

    1. Reviewer #1 (Public Review):

      Gao et al developed various genetic permutations of mouse models of kindlin-2 deficiency in the hepatocytes to explore its function. Hepatocyte-specific loss of kindlin-2 results in severe inflammatory liver injury, accelerated fibrosis/portal hypertension, and massive hepatocyte cell death by apoptosis. These effects are reversed by ablation of TNF signally or by caspase 8 deletion. AAV-mediated replacement of kindlin-2 protects the mice from chemically induced acute liver injury.

    1. Reviewer #1 (Public Review):

      Ruesseler and colleagues combine careful paradigm design, psychophysical and EEG analyses to determine whether information leakage during decision formation is strategically adjusted to meet changing task demands. Participants made motion direction judgments that required monitoring a continuous stream of dot motion for 'response periods' characterised by a sustained period of coherent motion in a leftward or rightward direction. Coherence was modulated on a frame-to-frame basis throughout the task furnishing a parametric regressor that could be used to interrogate the longevity of sensory samples in the decision process and their influence on corresponding EEG signals. Participants completed the task under varying conditions of response period length and frequency. Psychophysical kernel analyses suggest that sensory samples had a more short-lived impact on the participants' choices when response periods were rare, suggestive of greater information leakage. When the stimulus perturbations were regressed against the EEG data, it highlighted a centro-parietal component that showed increased responsiveness to large shifts in evidence when those shifts were more rare, suggestive of a role in representing surprise. An additional triphasic component was found to correlate with the time constant of integration as estimated from the kernel analyses.

      This is a very timely paper that addresses an important and difficult-to-address question in the decision-making field - the degree to which information leakage can be strategically adapted to optimise decisions in a task-dependent fashion. The authors apply a sophisticated suite of analyses that are appropriate and yield a range of very interesting observations. The paper centres on analyses of one possible model that hinges on certain assumptions about the nature of the decision process for this task which raises questions about whether leak adjustments are the only possible explanation for the current data. I think the conclusions would be greatly strengthened if they were supported by the application and/or simulation of alternative model structures.

      The behavioural trends when comparing blocks with frequent versus rare response periods seem difficult to tally with a change in the leak. The greater leak should result in a reduction in the rate of false alarms yet no significant differences were observed between these two conditions. Meanwhile, false alarms did vary as a function of short/long target durations which did not show any leak effect in the psychophysical kernel analyses. Are there other models that could reproduce such effects? For example, could a model in which the drift rate varies between Rare and Frequent trials do a similar or better job of explaining the data? This ties in to a related query about the nature of the task employed by the authors. Due to the very significant volatility of the stimulus, it seems likely that the participants are not solely making judgments about the presence/absence of coherent motion but also making judgments about its duration (because strong coherent motion frequently occurs in the inter-target intervals). If that is so, then could the Rare condition equate to less evidence because there is an increased probability that an extended period of coherent motion could be an outlier generated from the noise distribution? Note that a drift rate reduction would also be expected to result in fewer hits and slower reaction times, as observed.

      Some adjustment of the language used when discussing FAs seems merited. If I have understood correctly, the sensory samples encountered by the participants during the inter-response intervals can at times favour a particular alternative just as strongly (or more strongly) than that encountered during the response interval itself. In that sense, the responses are not necessarily real false alarms because the physical evidence itself does not distinguish the target from the non-target. I don't think this invalidates the authors' approach but I think it should be acknowledged and considered in light of the comment above regarding the nature of the decision process employed on this task.

      The authors report that preparatory motor activity over central electrodes reached a larger decision threshold for RARE vs. FREQUENT response periods. It is not clear what identifies this signal as reflecting motor preparation. Did the authors consider using other effector-selective EEG signatures of motor preparation such as beta-band activity which has been used elsewhere to make inferences about decision bounds? Assuming that this central ERP signal does reflect the decision bounds, the observation that it has a larger amplitude at the response on Rare trials appears to directly contradict the kernel analyses which suggest no difference in the cumulative evidence required to trigger commitment.

      P11, the "absolute sensory evidence" regressor elicited a triphasic potential over centroparietal electrodes. The first two phases of this component look to have an occipital focus. The third phase has a more centroparietal focus but appears markedly more posterior than the change in evidence component. This raises the question of whether it is safe to assume that they reflect the same process.

    1. Reviewer #1 (Public Review):

      The authors provide a comprehensive series of experiments to show that IF promotes rapid hepatocyte proliferation driven by the dual action of systemic FGF15 (intetinally-derived) and localized WNT signaling. Hepatocyte proliferation during periods of IF maintains a steady liver-to-body-mass ratio. This study provides the first example of the dietary influence on adult hepatocyte proliferation and is highly relevant to the putative beneficial effects of IF in multiple chronic diseases. Additionally, it challenges the view that liver tissue is quiescent except in patholgical injury.

    1. If you squint, open source could be seen as a very generous charitable donation to some of the largest and wealthiest corporations on the planet.
    1. Reviewer #1 (Public Review):

      This study elucidates a role of EHD2 as a tumor/metastasis promoting protein. Prior work has found varying results indicating that high expression of EHD2 is either associated with good or poor outcomes. In this work the authors find that EHD2 is expressed in both the nucleus and cytoplasm, and that high cytoplasmic to nuclear expression is associated with a poor prognosis. Using WT and either shRNA knockdown or CRISPR KO cells, they show that EHD2 promotes 3D growth, migration and invasion in vitro, and tumor growth and metastasis in vivo. Importantly, re-expression of EHD2 in KO cells rescues the loss of function phenotype. Mechanistically, the investigators show that the loss of EHD2 decreases the calveoli and that this decreases the Orai1/Stim induced calcium influx. Finally, they show that inhibitors of store operated calcium entry (SOCE) phenocopies the loss of EHD2. Together the data support a protumorigenic role for EHD2 via store-operated calcium entry and reinforce the utility of targeting calveoli and SOCE in tumors with high cytosolic EHD2. This study provides a rationale for using SOCE inhibitors in a subset of breast cancers, and a potential predictive biomarker for using SOCE inhibitors based on high expression of EHD2.

    1. Reviewer #1 (Public Review):

      The authors convincingly show directionally tuned signals in AD and RSC. RSC is found to have a lower proportion of HD cells than AD, and RSC HD cells are more sensitive to angular velocity than AD HD cells. Importantly, HD responses are shown to be tightly correlated between the two areas. Population decoding of head direction, performed on AD neuron ensembles or RSC ensembles, revealed similar shifts following visual cue rotation and also similar HD drift in darkness, indicating that the HD representation across both areas is coordinated. The study further finds that AD-to-RSC connections are relatively frequent, while RSC-to-AD connectivity is very sparse. This asymmetry in functional connectivity is matched by viral tracing results. Together, the results lead the authors to the conclusion that this corticothalamic connection is likely not driving visual landmark updating of the global head direction system.

      This is a welcome piece of work, providing the first assessment of the high degree of coherence between AD and RSC HD representations, using pairwise and population-level analysis methods, which had not been accessible before. It will be a valuable reference for researchers interested in inter-area interactions in the head direction system, leaving the question of how and where visual reference updates are fed into the HD circuit open for further investigations.

    1. Reviewer #1 (Public Review):

      This manuscript by the Karakas lab reports on new structures of the volume regulated LRRC8 anion channels. These ubiquitously expressed channels play key roles in cell volume regulation and in allowing efflux of organic osmolytes, neurotransmitters, and drugs. In addition to regulating cell volume LRRC8 channels might play roles in signal transduction, cell migration, apoptosis, tumor drug resistance, and stroke. Thus, elucidating their architecture and structure is of critical importance. LRRC8 channels are obligate multimers of variable stoichiometry, with the LRRC8A subunit being absolutely required for assembly of functional channels. Structures of homomeric LRRC8A and LRRC8D channels revealed a hexameric assembly with closed pores. However, the functional properties of these homomeric channels differ from those of recorded in cells, raising questions on the physiological relevance of these conformations. The authors here determine the structure of a LRRC8C-LRRC8A chimera (termed 8C-8A(IL125)) with functional properties that closely resemble those of native channels. Remarkably, the 8C-8A(IL125) chimera assembles as a heptamer with a large pore. Unexpectedly, in the structures the channel's pore is occupied by density that could correspond to lipids.

    1. Reviewer #1 (Public Review):

      In 2020, Sugisawa et al. reported that Piezo1ion channels can be activated by ssRNAs, both synthetic and derived from fecal matter, suggesting that these may be the first identified natural ligands to agonize Piezo channels. Nickolls et al., provide a careful and rigorous investigation of the effect of ssRNAs and fecal extracts on Piezo channel activity in three cell lines, using both calcium imaging and electrophysiology. They find that Piezo1 is not responsive to ssRNAs nor responsible for calcium flux in response to fecal extracts in HEK293 and RIN14b cells. Overall, this study addresses the question of ssRNAs as a Piezo ligand clearly and thoroughly, with rigorous, well-controlled experiments. Overall, I am excited about this study as a necessary clarification for the field of Piezo mechanosensation.

    1. Reviewer #1 (Public Review):

      This work identifies distinct contribution of direct (D1+) and indirect (Adora+, D2+) amygdalostriatal medium spiny cells in fear learning and plasticity. The authors combined freely moving calcium imaging with auditory fear learning assay to reveal tone, foot-shock and behavior (movement)-evoked activity of the two MSN population. While D1+ cells show plastic changes driven by fear learning and reaching their maximum tone responsiveness (PSTH) at fear retrieval, Adore+ cells activation remained constant. Furthermore, using optogenetic silencing they showed that the two MSN groups differently contribute to retrieval of fear memory. Both cells receive topographically organized insular cortical inputs which go through learning-induced long-term synaptic changes with opposite direction: postsynaptic LTP at D1 cells, while presynaptic LTD at Adora+ cells. These synaptic changes provide some level of explanation for distinct behavioral contribution of the two cell types in fear learning.

      This study focuses on a so far neglected member of the 'extended' amygdalar circuitry, the amygdalostratal transition zone. The data is well-presented, the experiments are in logical order, built on each other and the paper is easy to read and follow.

      However, some information regarding the connectivity (and function) of Astr have been presented in recent and earlier papers are missing from, or contradicting with, the present work. One reason to explain these is that the targeted striatal regions vary between experiments, and so, it is difficult to judge when the Astr and when the other part of the caudal (tail) striatum is examined. As these striatal regions are involved in different neuronal networks, their functional consequences could also be distinct. Without precisely clarifying and consistently targeting the aimed striatal region, it is difficult to interpret the findings of the present study (though those are relevant and important).

    1. Reviewer #1 (Public Review):

      In this manuscript, Zhang and colleagues created a transgenic mouse strain that expresses SYT-1-tdt in all neurons. They showed that the labelled SYT-1 colocalizes with multiple synaptic markers and label synapses in different regions. More importantly, they showed that the transgenic expression does not alter synaptic function using ephys assays. This is a straightforward paper that generated a useful reagent that will be used broadly.

    1. Reviewer #1 (Public Review):

      This is an interesting and timely paper investigating the impact on participation in cancer screening programs across Italy during the COVID-19 pandemic where there was massive disruptions to health services. What is of particular interest in this analysis was the investigation of social, educational and cultural factors that might have impacted access and participation to screening.

      - In the present study, the authors analyzed data collected by PASSI between 2017 and 2021, from interviews of more than 106,000 people, a representative sample of the Italian population aged 25-69 was selected but its not clear what was the representativeness by region, gender and age educational attainment? Also what is the total population (so I don't have to look it up). I am wondering if participation differed by characteristics and what approach to achieving the representative sample was made (e.g. replacement of individuals or oversampling certain strata where participation was lower).

      - For figures 5-8 what is the N for the different groups not just the %?

      - Table 2 to me is a key piece of information and very interesting can the authors formally test if there are signficant differences between the time periods?

    1. Reviewer #1 (Public Review):

      The authors introduce an online tool, CausalCell, to explore causal links in single-cell datasets. The authors investigate the process through examples based on existing data, offer comparisons of different algorithms, and suggest tips about the requirements and limitations of this approach. In my opinion, the main shortcoming is that the authors do not adequately justify whether the methods included in their tool are the most suitable methods for their intended analyses. The lack of a definite "ground truth" or "gold standard" also comes in the way clearly deciding which algorithms perform the best, especially when there are considerable differences between the results of different algorithms.

    1. Reviewer #1 (Public Review):

      The authors conducted a thorough analysis of the correlation between height and measures of cognitive abilities (what are essentially IQ test components) across four cohorts of children and adolescents in the UK measured between 1957 and 2018. The authors find the strength of the association between height and cognitive measures declined over this time frame--for example, among 10- and 11-year-olds born in 1958, height explained roughly 3% of the variation in verbal reasoning scores; this dropped to approximately 0.6% among those born in 2001. These associations were further attenuated after accounting for proxy measures of social class.

      The authors' analyses were performed carefully and their observations regarding declining height / cognitive measure associations are likely to be robust if we interpret their results with an important caveat: these results reflect measurements aimed at assessing cognition rather than cognition itself. The importance of this distinction is evidenced by the changing correlation structure of the cognitive measures over time. For example, age 11 verbal / math scores were correlated at >= 0.75 at the first two time points but dropped to 0.33 at the most recent time point. Similar patterns are present for the other cognitive measures and time points. The authors' conclude that such changes are unlikely to impact their primary findings, but I'm less certain. For example, one interpretation of this finding is that older cognitive measures were simply worse at indexing distinct cognitive domains and instead reflected a combination of cognitive ability together with non-specific factors relating to opportunity, health, class, etc. Further, height was historically a stronger proxy for class and economic status than it is today (e.g., by capturing adequate nutritional intake, risk for childhood disease, etc.). Together, then, previously high height / cognitive measure correlations might reflect the fact that both phenotypes previously indexed socio-economic factors to a greater extent than they might today (which is still non-negligible).

      Additionally, their findings add an interesting data point to a collection of recent results suggesting that the relationship between cognitive and anthropometric measures is complex and difficult to interpret. For example, studies using genetic markers to examine shared genetic bases have virtually all relied on methods assuming mating is random, which is not the case empirically. Howe et al. (doi.org/10.1038/s41588-022-01062-7) recently reported that the ostensible genetic correlation of -.32 between years of education and BMI attenuates to -.05 when using direct-effect estimates, which should theoretically be immune to the effects of non-random mating and other confounding variables. Likewise, Keller et al. (doi.org/10.1371/journal.pgen.1003451) and Border et al. (doi.org/10.1101/2022.03.21.485215) used very different approaches to arrive at the same conclusion that ~50% of the nominal genetic correlation between IQ and height could be attributed to bivariate assortative mating rather than shared causal biological factors. Given that assortative mating on both IQ measures and height involves many other traits (not just two as assumed in such bivariate models), the true extent to which height / IQ correlations reflect causal factors is plausibly even lower than these estimates suggest. For these reasons, I do not entirely agree with the authors' review of previous findings in the introduction, where they write "recent studies have suggested that links between higher cognition and taller height can be largely explained by genetic factors", though it is certainly true that this claim has been made.

    1. Reviewer #1 (Public Review):

      Li et al. have designed a study that examines specific mechanisms for how different DNA sequence variants in the common cancer gene p53 (also known as TP53) influence the sensitivity of tumors to a variety of common cancer treatments. Specifically, they examine a handful of p53 variants with respect to glioblastoma and its response to platinum-based chemotherapy and to radiation therapy. The authors begin by mentioning that looking at DNA variants in cancer is useful but also incomplete: methylation, PTMs, and non-DNA sequence variants can also be critical. They then mention that they have created a model showing that nearly all cancers with p53 mutations have loss-of-function variants and that many cancers with "normal" wildtype p53 in fact have variants causing LOF. These p53 LOF tumors lead to worse patient outcomes, but the authors here show that these tumors appear to be more susceptible to radiation and platinum-based chemotherapy, which they say they have validated in glioblastoma xenografts. This potentially opens up a new avenue for precision medicine for many different sources of cancer that share common p53 LOF variants.

      The authors have taken a modern approach towards cancer diagnosis and shown how this can improve targeted treatments across a large array of cancer types. They have provided a reasonably convincing proof of concept of this approach for n = 35 PDXs in one cancer type. By and large, the approach and results are reasonable, although many of the exact results concerning the genes and pathways identified that covary with the various treatments and p53 variants are unclear. For instance, the feature selection seems to be somewhat ad hoc, e.g. the method used to determine p53 LOF from p53 WT in the TCGA data was not the same method used for determining p53 LOF from p53 WT in the PDX data. The TCGA AUROCs were incredibly good - over 99% - versus more like 75% for the actual proof of concept. While any significant p-value is fine for basic research, it would be nice to know how this could be improved and bring the results in Figure 4 from ~75% to the >99% that would be necessary for use as a medical diagnostic or for treatment selection for precision medicine. However, there are significant questions regarding the specific findings uncovered: do the gene pathways identified through bioinformatic analysis fit in with the many highly-studied mechanistic roles of p53? Do the cohort selections - which vary by an order of magnitude in sample size, and come from different locations and different tissues - make statistical sense for cross-validation?

    1. Reviewer #1 (Public Review):

      NADPH oxidases are a family of membrane enzymes that produce reactive oxygen species (ROS). NOX2 is the most well-studied member of the NADPH oxidase family, and the proper function of NOX2 is critical for innate immunity against pathogens in mammals.

      The study by Dr. Chen and colleagues used antibodies to facilitate the structural determination of the high-resolution structure of the NOX2-p22 complex, which is otherwise challenging for single-particle analysis due to its flexibility and relatively small molecular weight. The work uncovered the high-resolution information between NOX2-p22 interaction and conformational flexibility between the DH domain and the transmembrane domain of NOX2. This structural study provides valuable information for a mechanistic understanding of NOX2 activation at the molecular level.

      The weakness of the paper is the lack of in-depth analyses regarding structural discoveries. In addition, a study by Noreng S et al on the structure of the NOX2-p22 complex is now available.

    1. Reviewer #1 (Public Review):

      Chondrosarcoma is a rare and aggressive cancer type with a poor prognosis and lacks effective treatment options. Developing an effective strategy for targeting chondrosarcoma is therefore considered an unmet clinical need. The goal of this study is to provide the molecular basis for chondrosarcoma progression and identify a potential strategy/agent for targeting chondrosarcoma. The study reveals that EZH2/hSULF1/c-Met axis is a critical signaling pathway for chondrosarcoma and provides proof of principle evidence that targeting c-MET by pharmacological approaches is an effective strategy to suppress tumor growth in chondrosarcoma mouse models. The aims to be explored for the study are novel and have been well accomplished. The conclusions from this current study are well supported by the compelling and robust datasets using diverse approaches. The study not only reveals a novel insight into how chondrosarcoma progression occurs but also offers the potential strategy for targeting chondrosarcoma, hence significantly advancing the field.

    1. Reviewer #1 (Public Review):

      It has been shown that selenium protects against the development of epilepsy, and behavioral comorbidities, as pointed out by the authors. This paper attempts to show it does if administered later after chronic seizures start. While clinically relevant, as noted by the authors, the paper seems not to be a major advance beyond the prior study. The antiseizure effect is also not very convincing because the effect size is so small and the variance so high. The data about behavior is more convincing but similar data were in the previous paper, so it is not very novel.

      The data showing changes in PP2A are interesting and while logical that it contributes to the effects of sel, one would like to see proof that this is the basis of sel effects. Same for hyperphosphorylated tau, telomere length, etc. The doubt is because these are indices that change after many types of experiments and they change many aspects of brain and peripheral physiology. Regarding molecular data, how these provide insight and comparison to other data sets of this kind would be valuable.

    1. Reviewer #1 (Public Review):

      Estimating the effects of mutations on the thermal stability of proteins is fundamentally important and also has practical importance, e.g, for engineering of stable proteins. Changes can be measured using calorimetric methods and values are reported as differences in free energy (dG) of the mutant compared to wt proteins, i.e., ddG. Values typically range between -1 kcal/mol through +7 kcal/mol. However, measurements are highly demanding. The manuscript introduces a novel deep learning approach to this end, which is similar in accuracy to ROSETTA-based estimates, but much faster, enabling proteome-wide studies. To demonstrate this the authors apply it to over 1000 human proteins.

      The main strength here is the novelty of the approach and the high speed of the computation. The main weakness is that the results are not compared to existing machine learning alternatives.

    1. Reviewer #1 (Public Review):

      This manuscript uses two OR molecues as a model to understand the mechanism behind their ligand specificity. It combines a series of targeted mutations and domain swapping followed by functional analysis in Xenopus oocyte expression system to analyse functional aspects of the modified ORs. It also models the various OR structures. The authors find that a single amino acid residue is critical for ligand specificity and that this is mediated by space constraints generated in the ligand docking region. The manuscript is generally well written and the data are clear and well represented.

    1. Reviewer #1 (Public Review):

      The authors investigate the relative importance of the bee host and bacterial microbiome in processing the nectar secondary metabolite amygdalin, with a focus on understanding the contributions of the different members of the microbiome, and the enzymatic basis for metabolic transformations. The manuscript clearly describes the experimental procedures, presents the results in graphically appealing figures and clear text, and puts the work into a broader context in the discussion. The conclusions are backed by sophisticated in vitro and in vivo experimental data. A particular strength of the manuscript is the combined use of genomic, gene expression, proteomic, and small metabolite analyses to pin down the mechanistic basis of the degradation of amygdalin. While at this stage the authors cannot infer the importance of their findings for bee health, their insights and methods should stimulate additional experiments into the role of microbial conversion of dietary metabolites for bee health.

    1. Reviewer #1 (Public Review):

      Building upon the previous evidence of activation of auditory cortex VIP interneurons in response to non-classical stimuli like reward and punishment, Szadai et al., extended the investigation to multiple cortical regions. Use of three-dimensional acousto-optical two-photon microscopy along with the 3D chessboard scanning method allowed high-speed signal acquisition from numerous VIP interneurons in a large brain volume. Additionally, activity of VIP interneurons in deep cortical regions was obtained using fiber photometry. With the help of these two imaging methods authors were able to extract and analyze the VIP cell signal from different cortical regions. Study of VIP interneuron activity during an auditory go-no-go task revealed that more than half of recorded cortical VIP interneurons were responding to both reward and punishment with high reliability. Fiber photometry data revealed similar observations; however, the temporal dynamics of reinforcement stimuli-related response in mPFC was slower than in the auditory cortex. The authors performed detailed analysis of individual cell activity dynamics, which revealed five categories of VIP cells based on their temporal profiles. Further, animals with higher performance on the discrimination task showed stronger VIP responses to 'go trials' possibly suggesting the role of VIP interneurons in discrimination learning. Authors found that reinforcement related response of VIP interneurons in visual cortex was not correlated with their sensory tuning, unveiling an interesting idea that VIP interneurons take part in both local as well as global processing. These observations bring attention to the possible involvement of VIP interneurons in reinforcement stimuli-associated global signaling that would regulate local connectivity and information processing leading to learning.

      The state-of-the-art imaging technique allowed authors to succeed in imaging VIP interneurons from several cortical regions. Advanced analyses revealed the nuances, similarities and differences in the VIP activity trend in various regions. The conclusions about reinforcement stimuli related activity of VIP interneurons made by the authors are well supported by the results obtained, however some claims and interpretations require more attention and clarification.

    1. Reviewer #1 (Public Review):

      In this work the authors study the effects of the accumulation of endogenously produced Advanced Glycation End-products (AGEs) on feeding behaviors in C. elegans. AGEs are produced during the metabolism of all organisms, and also, they are produced by the food industry through Mainard reactions. In this sense, the objectives of this study are not only to provide basic information relevant to phenomena that are likely to be conserved throughout the animal kingdom but also to provide information that could be important in human health for the understanding of disorders caused by the consumption of processed foods.

      The methodology includes as read out very robust and supercharacterized assays of food intake in C. elegans, such as pharyngeal pumping and food depletion.<br /> As a general evaluation of the manuscript, I think the authors could provide more detailed mechanistic information about how MGH-1 acts on the tyraminergic pathway to potentiate food intake. While they find important players, they do not quite find how these players interact with each other, nor which cells or neural circuits are governing the processes described.

      In summary, I consider the initial objective of the manuscript to be extremely significant, but I believe it falls short in the mechanistic explanation of the observations described.

    1. Reviewer #1 (Public Review):

      This report describes an exhaustive analysis of behavior in a complex associative learning paradigm that blends aversive Pavlovian and appetitive instrumental elements. The hand-scoring technique is rigorous and documented to a greater degree than what is typically reported in papers using human raters to quantify animal behavior. Near-complete ethograms offer a novel, high-resolution look at how aversive cues exert distinct effects on appetitive and aversive behavior.

      From the perspective of the rodent subject, there is quite a lot going on in the experimental chamber in this study. It's an environment in which appetitive instrumental action is set against multiple predictive cues signaling differing degrees of danger and safety. The test is fully on-baseline, occurring in the same place as training. The rich web of associations formed has a predictably complex influence on behavior. The authors contrast this complexity with much of the rest of the literature, in which freezing is reported to predominate when an aversive CS is presented. Indeed, most conventional studies of aversive associative learning train subjects on a single tone-shock association and test in a neutral context. The contrast between the common approach and the one taken by the authors suggests questions central to understanding the current report. Does being tested in an associatively complex context promote the pattern of behaviors that the authors observe? Or is it a question of learning history - would, following this kind of complex training, an off-baseline test in a neutral environment, produce the same suite of outcomes in response to the danger cue? Answers to these questions would go some distance toward nesting this paper in a wider body of knowledge about defensive reactions to aversive conditioned stimuli. Data speaking to these issues would also increase the work's impact by demonstrating the way in which a given response can be modulated by other learning.

    1. Reviewer #1 (Public Review):

      The paper, fundamentally, is a description of the accuracy of individual model and ensemble model short-term forecasts of COVID-19. This has been done before in both weather and infectious disease. So what are the contributions of this manuscript? I see the following:

      1. The authors show that ensemble prediction (a straight average) generally outperforms individual component models. This is not new and has been shown, as the authors cite, for weather, climate, and infectious disease.<br /> 2. Use of the median estimate across models, rather than the mean, buffers against outliers. This is a well-recognized workaround for right-skewed distributions, though the specific finding in this study is of some importance, as this hasn't always been the case (noted by the authors in their discussion).<br /> 3. Deaths are better forecasted than cases. This is not new, either, as the authors note, as deaths are a lagged function of cases/infections.<br /> 4. It presents the archive of European COVID-19 forecasts.

      Although I don't see a lot of novelty in these findings, this COVID-19 forecasting work is important and represents a considerable effort on part of the individual modelers. The paper is well written, but it doesn't show much that is novel methodologically. For instance, it doesn't propose and validate an approach for improving forecasting or projection accuracy. Are there new ways to handle or predict behavioral, vaccination uptake, or viral changes? Are there novel post-processing approaches, other than 'ensembling' that could improve forecast accuracy?

    1. Reviewer #1 (Public Review):

      Earlier this year Skolnick and colleagues managed to tweak AlphaFold to predict protein complexes (reference 23 in the current manuscript). They also added a score that allows the detection of true protein-protein interactions among arbitrary protein pairs. Thus, their methodology allows reliable prediction of homo- and hetero-meric protein-protein interactions, and predicting the structure of the corresponding protein complexes. Leveraging this methodology, the current manuscript describes a very interesting application to a set of about 1,500 E. coli proteins of the outer membrane, the periplasm and the inner membrane of this Gram negative bacteria. They explore protein-protein interactions among this protein set, which they refer to as 'envelome'. Their results reproduce known protein complexes, such as the translocon, and suggest many yet unknown interactions that make biological sense.

      A main strength here is the generation of ample hypotheses to be tested in experiment, i.e., all protein-protein interactions of high predicted accuracy. Another strength is that the methodology is readily applicable to other systems. However, a few outstanding issues need to be clarified.

      1. Even though the methodology was already introduced, it should be described in some detail. Most importantly, AlphAfold's measures of accuracy have been part of the loss function during training/testing. What about the measure of protein-protein interaction accuracy? Was it also in the loss function?<br /> 2. Figure 1a (upper panel, PpiD) includes quite a few promising hits but only the first, third, and 12th were considered. How were these chosen? For example, why not consider the second? The lower panel (YfgM) also shows many promising hits but only the first was chosen. Why not more?<br /> 3. Likewise, only two of the top hits in Figure 4 are considered. What about the rest? For example, why taking into account the second best hit while skipping the first?<br /> 4. Authors argue that the unstructured part of OmpA, which wraps around SurA, is to be trusted, which may be the case. But a more likely explanation is that it is an artefact, in agreement with the very low confidence assigned by AlphaFold.<br /> 5. Figure 5. How is this predicted structure compare with the known structure of the complex? In particular, how similar are the predicted and known structures of the individual subunits, and how similar are the predicted docking poses to the known ones?<br /> 6. Authors should make the results easily accessible to all. Maybe as Cytoscape and CyToStruct sessions for easy visualization.<br /> 7. Finally, AlphaFold was trained and tested mostly with water-soluble protein. Thus, application to outer membrane proteins is a bit risky. Maybe authors can comment on this.

    1. Reviewer #1 (Public Review):

      The authors present a study of figure-ground segregation in different species. Figure-ground segregation is an important mechanism for the establishment of an accurate 3D model of the environment. The authors examine whether figure-ground segregation occurs in mice in a similar manner to that reported in primates and compare results to two other species (Tree shrews and mouse lemurs). They use both behavioral measures and electrophysiology/two-photon imaging to show that mice and tree shrews do not use opponent motion signals to segregate the visual scene into objects and background whereas mouse lemurs and macaque monkeys do. This information is of great importance for understanding to what extent the rodent visual system is a good model for primate vision and the use of multiple species is highly revealing for understanding the development of figure-ground segregation through evolution.

      The behavioral data is of high quality. I would add one caveat: it seems unfair to report that the tree shrews could not generalize the opponent motion stimulus as it seems they struggled to learn it in the first place. Their performance was below 60% on the training data and they weren't trained for many sessions in comparison to the mice. Perhaps with more training the tree-shrews might have attained higher performance on the textures and this would allow a more sensitive test of generalization. The authors should qualify their statements about the tree-shrews to reflect this issue.

    1. Reviewer #1 (Public Review):

      This study used a multidimensional stimulus-response mapping task to determine how monkeys learn and update complex rules. The subjects had to use either the color or shape of a compound stimulus as the discriminative dimension that instructed them to select a target in different spatial locations on the task screen. Learning occurred across cued block shifts when an old mapping became irrelevant and a new rule had to be discovered. Because potential target locations associated with each rule were grouped into two sets that alternated, and only a subset of possible mapping between stimulus dimensions and response sets were used, the monkeys could discover information about the task structure to guide their block-by-block learning. By comparing behavioral models that assume incremental learning, quantified by Q-learning, Bayesian inference, or a combination, the authors show evidence for a hybrid strategy in which animals use inference to change among response sets (axes), and incremental learning to acquire new mappings within these sets.

      Overall, I think the study is thorough and compelling. The task is cleverly designed, the modeling is rigorous, and the manuscript is clear and well-written. Importantly there are large enough distinctions in the behavior generated by different models to make the authors' conclusions convincing. They make a strong case that animals can adopt mixed inference/updating strategies to solve a rule-based task. My only minor question is about the degree to which this result generalizes beyond the particulars of this task.

    1. Reviewer #1 (Public Review):

      In the submitted manuscript, the authors observed that Glycine treatment could phenocopy deficiency of NINJ1, a recently discovered cell surface molecule critical for plasma membrane rupture, and also inhibit the aggregation of NINJ1. However, whether Glycine directly inhibits NINJ1 was not examined, and thus, the manuscript falls short of having a significant impact in the field.

      Strengths of the manuscript:

      1. Timely. There is great interest in understanding the mechanism of plasma membrane rupture.<br /> 2. The data provided using several mouse and human cell culture systems overall support the conclusion that Glycine targets NINJ1-mediated plasma membrane rupture (as the title says).

      However, most of the presented data is predictable from previous publications. Direct evidence of the mechanism by which NINJ1 is inhibited by Glycine, or in other words, NINJ1 as the direct target of Glycine, was not provided in this manuscript. It is therefore still possible that Glycine acts indirectly upstream of NINJ1. This possible indirect mechanism can be inferred from previous reports where other amino acids such as Serine also could inhibit cell lysis (reviewed in PMID: 27066896).

    1. Reviewer #1 (Public Review):

      In order to study odor response dynamics in the olfactory peripheral organ, Kim et al. employs extracellular sensillum recording from the locust antenna to a set of 4 odors at different concentrations. Using spike sorting to assign odor responses to single olfactory sensory neurons (OSNs), the authors demonstrate that OSNs exhibit four distinct response motifs comprising two types of excitation, namely fast and delayed excitatory responses, as well as inhibitory responses in form of offset responses and inhibition. Notably, OSNs can switch between these four motifs depending on the odor applied. This finding is highly interesting and facilitates odor classification as demonstrated by computational modeling in this study. Furthermore, the authors demonstrate that each response motifs follows different adaptation profiles which further results in an increased coding space. The authors conclude and provide evidence with their model that the experimentally observed response dynamics also facilitate determining the distance to the odor source. The obtained results are novel and demonstrate a new dimension of odor response properties at the peripheral level. However, given that the authors used a very limited set of chemically similar odors and considering that the broad tuning and wiring of OSNs in the locust is special and follows different rules compared to the olfactory circuitry of OSNs in other insects (i.e. locust OSNs do not converge onto a single glomerulus but target multiple glomeruli), I wonder whether the observed distinct response motifs are a general phenomenon or a rather special case. I therefore recommend that the authors discuss their findings in the light of these key issues before general conclusions with regard to odor coding rules is being drawn. Do these response motifs also occur for highly ecologically relevant odors, such as PAN, where a rather specialized olfactory circuit would be assumed? Hence, the MS would benefit if those questions would be addressed as well. In addition, the computational modeling approach is written in specialized terms and is therefore difficult to grasp for readers lacking modeling expertise.

    1. Reviewer #1 (Public Review):

      The current manuscript by Schwager and colleagues describes a mechanism by which poorly migratory MDA-MB-231 cells can be metastatic. This study follows a recent paper from the same group (published in January) demonstrating that these poorly migratory cells are more metastatic than their highly migratory counterparts, and that this is due at least in part to E-Cadherin expression and the ability to form circulating tumour cell (CTC) clusters. In the current study, the authors show that the low migratory cells secrete unique EVs that can activate fibroblasts, concomitant with metastatic progression, and that this function is dependent on the presence of Tg-2. The novelty of this work is in the phenotypic heterogeneity of tumour cells, even within cell lines, and the importance the microenvironment in mediating metastasis associated with this diversity. While interesting, this work uses only one model, which was very recently published. The study, I think, would require repetition within additional models, as well as the inclusion of mechanistic studies designed to determine why the EV cargo differs between the highly and poorly migratory subclones.

    1. Reviewer #1 (Public Review):

      It has previously been shown that deletion of the GluA3 subunit in mice leads to alterations in auditory behavior in adult mice that are older than a couple of months of age. The GluA3 subunit is expressed at several synapses along the auditory pathway (cochlea and brainstem), and in ko mice changes in brainstem synapses have been observed. These previously documented changes may account for some of the deficits in hearing in adult ko mice.

      In the current study, the authors investigate an earlier stage of development (at 5 wks) when the auditory brainstem responses (ABRs) are normal, and they ask how transmission persists at inner hair cell (ihc) ribbon synapses in GluA3 ko mice. They discovered that deletion of GluR3A significantly changed 1) the relative expression of Glu A2 (dramatically downregulated) and A4 subunits at SGN afferents, and 2) caused morphological changes in ihc ribbons (modiolar side) and synaptic vesicle size (pillar).

      The changes documented in the 5 wk old GluA3ko mice were not necessarily predicted because in general the mechanisms involved in shuffling GluA receptors at this synapse (or other sensory synapses) are not completely understood; furthermore, much less is known about the role of differentiation of ihc-sgn synapses along a modiolar-pillar axis. With that said, the only shortcoming of the study is a lack of explanation for the observed changes in the synaptic structure; but this is not specific to this study.

      Given the quality of the data and the clarity of presentation of results, this is a very valuable study that will aid and motivate researchers to further explore how auditory circuitry develops, and becomes differentiated, at the level of ihc-sgn synapses.

    1. Reviewer #1 (Public Review):

      In this study, Lefebvre et al. investigate the interplay between tissue geometry and the expression patterns of Runt and Tartan in establishing anisotropic myosin localization during germband extension in the Drosophila embryo. Using live and fixed light sheet imaging, computational analysis, and modeling, the authors establish a global time-resolved map of Runt expression and myosin localization during germband extension. They show that a posterior Runt stripe increasingly deviates from the dorsoventral (DV) axis during elongation, while myosin anisotropy in this region transiently deviates from the DV axis and then realigns with this axis after a delay. The authors attribute this delay to the timescale of myosin turnover and the realignment to an unidentified geometric cue. The authors develop a model that can largely account for myosin localization in wild-type, eve mutant, and twist mutant embryos using a myosin lifetime parameter representing myosin turnover. These results provide evidence for a static signal that aligns myosin anisotropy with the DV axis during elongation.

      The strengths of this paper are the combination of modeling and quantitative measurements. Powerful in toto measurements show that myosin anisotropy becomes increasingly misaligned with Runt, an essential regulator of myosin planar polarity, at later stages of elongation in posterior regions of the embryo. In addition, the authors present a simple model in which changes in one parameter representing the myosin lifetime can recapitulate the relationship between myosin and edge orientation in wild-type, eve mutant, and twist mutant embryos.

      The main weakness of the paper is that the authors do not directly test if their model correctly predicts the myosin lifetime in eve mutants, twist mutants, or in Fat2-RNAi embryos with altered geometry. As myosin turnover is the key parameter in their model, measuring myosin dynamics in these backgrounds would provide an important first test of their model. In addition, the authors should attempt to relate their measurements of myosin dynamics in wild-type embryos to the myosin lifetime value predicted by their model, and they should consider alternative explanations that could account for their observations in wild-type and mutant embryos.

    1. Reviewer #1 (Public Review):

      In this manuscript, Winter and colleagues define the sensitivity of cancer cells lacking the mitochondrial AAA+ ATAD1 to proteasome inhibition. They show that ATAD1 is often co-deleted with PTEN¬ in many different types of cancer. Using two complementary CRISPR screens in two distinct cell models, they identified the mitochondrial E3 ubiquitin ligase MARCH5 as a gene whose deletion is synthetically lethal with ATAD1. Since MARCH5 was previously reported to function to attenuate apoptotic signaling through mechanisms including promoting degradation of pro-apoptotic factors including BIM1, they sought to define the specific role of ATAD1 in regulating pro-apoptotic factor. They present evidence that ATAD1 extracts the pro-apoptotic protein BIMEL from mitochondria to facilitate its inactivation by mechanisms including degradation and inhibitory phosphorylation - a mechanism that appears enhanced during proteasome inhibition. This suggested that ATAD1-deficient cells could be preferentially sensitive to proteasome inhibitors. Consistent with this, expression of ATAD1 in ATAD1-deficient cells decreases sensitivity to proteasome inhibition. Similarly, depletion of ATAD1 in PC3 cells increased sensitivity to proteasome inhibition in xenografts, although somewhat curiously a corresponding increase in BIM was not readily observed (NOXA levels did increase). Finally, the authors show that prostate cancer patients with combined PTEN1/ATAD1 deletion show improved survival as compared to tumors where PTEN1 was deleted alone. Ultimately, these results support a model whereby ATAD1 promotes tumor cell survival and highlights that ATAD1 deletion may represent a vulnerability that can be exploited to treat tumors through the use of proteasome inhibitors.

      Overall, this is an interesting and generally well-performed study that defines the mechanistic and functional implications of a genetic 'hitchhiker' in the context of cancer cell survival. The synthetic lethality for ATAD1 and MARCH5 observed using two different genetic approaches (deletion/overexpression) in two different cell models underscores a strong link between these two genes. Further, the data showing an important role for ATAD1 in regulating BIM mitochondrial localization/cytosolic phosphorylation are interesting. The evidence demonstrating relationships between ATAD1 and proteasome sensitivity is also convincing. However, there are some weaknesses. For example, the direct relationship between ATAD1-dependent prosurvival activities and BIM is not clearly defined. This is evident as BIM1 depletion did not influence ATAD1-deficient PC3 cells' sensitivity to bortezomib and BIM was not significantly impacted in the xenograft models. BIM deletion did partially rescue synthetic lethality in Jurkat cells deficient in both MARCH5 and ATAD1, indicating a potential role in those cells. While the authors do address this, these results do create a disconnect within the studies that complicates the overall interpretation, as the specific importance of BIM regulation by ATAD1 in different models is not consistent or always clear. Regardless, this study does reveal new insights into the genetic relationship between ATAD1 deficiency and proteasome inhibition that could have direct therapeutic potential to improve the treatment of patients. Further, considering that the anti-apoptotic roles for ATAD1 appear to extend beyond BIM regulation, this will open new avenues for investigation of the underlying molecular mechanisms whereby ATAD1 contributes to regulating apoptotic signaling in cancer and other models. With that being said, tempering the writing to better highlight that BIM regulation does not explain the ATAD1 protection observed across cancer cell models (it is the case in some, but not all) would be helpful. While there is value in the new mechanistic insight provided into the potential mechanism of ATAD1-dependent apoptotic regulation, more focus on the specific relationship between ATAD1 deficiency and proteasome inhibitor sensitivity would better suit the current work.

    1. Reviewer #1 (Public Review):

      Pathogen effectors promote parasitism either in the apoplast or cytoplasm. Unexpectedly, the work described here suggests that FolSpv1 first interacts with SlPR1 in the apoplast and then translocates SlPR1 into the nucleus of tomato plant cells. The authors suggested that the FolSpv1-mediated translocation of SlPR1 into the nucleus prevented the generation of CAPE1, leading to compromised immunity in tomato plants. The study additionally showed that acetylation of FolSpv1 K167 protects the protein from ubiquitination and proteasome-mediated degradation in both the fungal cell and plant cell. Overexpression of SlPR1 or exogenous application of CAPE1 enhanced resistance to F. oxysporum, indicating that CAPE1 contributes to disease resistance to the pathogen in tomato plants. This is consistent with prior reports that CAPE1 positively regulates plant immunity. Y2H screen followed by BiFC and co-IP supported SlPR1 as a target of FolSpv1. Most importantly, incubation of the SlPR1 recombinant protein with FolSvp1 led to uptake of both FolSvp1 and SlPR1 by tomato root protoplasts and nuclear localization of both proteins. Consistent with their model, NLS sequence is required for FolSpv1 virulence function and re-localization of SlPR1 in the nucleus. Furthermore, disease resistance conferred by SlPR1 overexpression in tomato plants could be reversed by overexpression of FolSpv1 in the fungus. Overall, the work represents a potentially significant advance in effector biology of phytopathogens. However, it is too early to exclude the possibility that the nucleus-dependent virulence function of FolSpv1 is independent of CAPE1. It is a bit strange why nuclear localization of SlPR1 is required for preventing CAPE1 generation. The following concerns need to be addressed.

      1. Fig 6E shows that CAPE1 is released only upon Fol infection. This appears to contradict with the notion that FolSpv1 prevents CAPE1 release. However, Fol strain overexpressing FolSpv1 prevented the release of CAPE1. It is necessary to compare WT and the mutant strain in which the FolSvp1 gene is deleted. One would expect that the mutant strain induces significantly more CAPE1 release. Similarly, mutant strain complemented with the nls1 construct needs to be tested to see whether nuclear localization is required for preventing CAPE1 release.<br /> 2. SlPR1 is localized in the apoplast in a manner dependent on the signal peptide (Fig 5-figure supplement 1). Overexpression of SlPR1 with added NLS but lacking the signal peptide failed to enhance disease resistance to Fol infection (Fig 7G). What about overexpression of SlPR1 lacking the signal peptide without the added NLS? Does retention of SlPR1 in the cytoplasm sufficient to abolish its function? It is not even discussed why SlPR1 has to be in the nucleus to prevent CAPE1 release.<br /> 3. FolSvp1 carrying the PR1 signal peptide interacted with SlPR1 in the apoplast (Fig 6D and Fig 6-figure supplement 2). Why weren't these proteins translocated into the nucleus? These seem to contradict the in vitro uptake data. It seems that either no or only a very small proportion of SlPR1 transiently expressed in tobacco cells is located in the nucleus. Fig 7C shows that infection of the WT strain, but not the nls1 mutant strain, allowed detection of SlPR1 in the nucleus of tomato cells. However, it is not clear how much of SlPR1 remain in the apoplast or cytoplasm. Is the FolSpv1 protein secreted by Fol sufficient to translocate a significant portion of SlPR1 into the nucleus? The authors are suggested to examine apoplastic and cytoplasmic protein fractions for the relative amounts of SlPR1 after Fol infection.<br /> 4. Fig 7J and 7K, a better experiment would be to pretreat WT tomato plants with CAPE1 prior to inoculation with WT and FolSpv1 OE strains. The pretreatment should eliminate the virulence function of FolSpv1 OE if the virulence is solely dependent on the prevention of CAPE1 release.

    1. Reviewer #1 (Public Review):

      This report describes evidence that the main driving force for stimulation of glycolysis in DGC neurons by electrical activity comes from influx of Na+ including Na+ exchanging into the cell for Ca2+. The findings are presented very clearly and the authors' interpretations seem reasonable. This is important and impactful because it identifies the major energy demand in excited neurons that stimulates glycolysis to supply more ATP.

      Strengths are the highly rigorous use of fluorescent probes to directly monitor the concentrations of NADH/NAD, Ca2+ and Na+. The strategies directly test the roles of Na+ and Ca2+.

    1. Reviewer #1 (Public Review):

      The 'ForensOMICS' approach is an exciting new area that clearly needs further attention. Despite the current paper being a proof-of-concept, the authors have taken due care and diligence to present the findings of the work in a transparent manner, being careful not to draw hard conclusions based on preliminary experimentation.

      Despite being one of the most critical aspects of forensic investigations involving human remains, the estimation of PMI still presents significant challenges. This issue forms the premise of the current work, and this is clearly addressed in both the results and the thorough discussion. The selection of bone tissue as the target matrix is also quite unique and valuable, particularly in scenarios where other more common matrices (like soft tissues) are depleted, as is explained in the work. It is clear that, given further studies and validation, this approach could have a profound impact on the operational world of forensics.

    1. Reviewer #1 (Public Review):

      The authors of this manuscript report that human DUX4 and mouse Dux4 interact with STAT1 and inhibit interferon-stimulated gene transcription (ISG). The different functional domains of DUX4 were investigated to evaluate which ones are necessary for ISG. DUX4 transcriptional activity was found not to be necessary for ISG, rather the DUX4 C-terminal domain (CTD) was necessary and sufficient to suppress ISG. Employing liquid chromatography-mass spectroscopy (LC-MS), the DUX4 CTD was found to interact with several polypeptides present in human myoblasts. Two key regulators of innate immune signaling, STAT1, and DDX3X, ranked at the top of the list of candidate DUX4-CTD interactors. Immunoprecipitation confirmed DUX4-CTD interaction with STAT1, DDX3X, and several other polypeptides identified by LC-MS. Two regions of DUX4 were found to mediate interaction with STAT1. Amino acids 271-372 were necessary for co-IP of STAT1, and amino acids 372-424, containing (L)LxxL(L) motifs, could enhance binding to phosphorylated STAT1. IFN-gamma treatment enhanced DUX4-CTD binding to wild-type STAT1 and of the STAT1-S727A mutant. In contrast, IFN-gamma did not enhance the binding of DUX4 to the STAT1-Y701A mutant, indicating that DUX4-CTD and STAT1 interaction is promoted by STAT1 -Y701 phosphorylation. A mechanistic investigation of DUX4-STAT1 interaction was conducted by chromatin immunoprecipitation which revealed reduced IFN-gamma-induced STAT1 binding and Pol-II recruitment at promoters of several ISGs. Treatment with IFN-gamma of myoblasts derived from patients affected by facioscapulohumeral dystrophy (FSHD) showed that myoblasts expressing endogenous DUX4 failed to express the IDO1 gene which was, on the other hand, expressed in FSHD myoblasts not expressing DUX4. The majority of Ewing fusion-negative small blue round cell sarcomas have a genetic rearrangement between the CIC and DUX4 genes creating a fusion protein containing the C-terminal (L)LxxL(L) motif of DUX4. The Kitra-SRS sarcoma cell line expresses CIC-DUX4. IFN-gamma treatment of the Kitra-SRS cells showed very low induction of ISGs. Knock-down of the CIC-DUX4 fusion RNA resulted in a substantially increased IFN-gamma induction of ISGs whereas a corresponding knock-down in human myoblasts, which do not express CIC-DUX4, did not alter ISG induction.

      This is an important and compelling study that sheds light on a molecular mechanism by which DUX4 inhibits IFN-mediated immune response with potential translational relevance for the treatment of DUX4-expressing cancers. The experiments are rigorously executed and controlled for, and the conclusions are well supported by the presented data.

    1. Reviewer #1 (Public Review):

      The authors sought to identify the relationship between social touch experiences and the endogenous release of oxytocin and cortisol. Female participants who received a touch from their romantic partner before a stranger exhibited a blunted hormonal response compared to when the stranger was the first toucher, suggesting that social touch history and context influence subsequent touch experiences. Concurrent fMRI recordings identified key brain networks whose activity corresponded to hormonal changes and self-report.

      The strengths of the manuscript are in the power achieved by collecting multi-faceted metrics: plasma hormones across time, BOLD signal, and self-report. The experiment was cleverly designed and nicely counterbalanced. Data analysis was thorough and statistically sophisticated, making the findings and conclusions convincing.

      This work sheds new light on potential mechanisms underlying how humans place social experiences in context, demonstrating how oxytocin and cortisol might interact to modulate higher-level processing and contextualizing of familiar vs. stranger encounters.

    1. Reviewer #1 (Public Review):

      Overview:

      In this work, the authors set to study the effects of topographic connectivity in a hierarchical model of neural networks. They hypothesize that the topographic connectivity, often observed in cortical networks, is essential for signal propagation and allows faithful transmission of signals.

      To study the effects of topographic connectivity on the dynamics, the authors consider a network composed of several layers. Each layer is a recurrent neural network with excitatory and inhibitory subpopulations. The excitatory neurons in each layer enervate a subpopulation of the following layer. The receiving excitatory subpopulation targets a specific group in the next layer and so on. This procedure leads to separate channels that carry the inputs through the network. The authors study how the degree of specificity in each targeted projection, called 'modularity,' affects signal propagation through the network.

      The authors find that the network reduces noise above a critical level of network modularity: the deep layers show a clear separation of an active channel and inactive channels, despite the noisy input signal. They study how different dynamical and structural properties affect the signal propagation through the network layers and suggest that the dynamics can implement a winner-takes-all computation.

      Strengths and novelty:

      - Topographic projections, in which subpopulations of neurons target specific cells in efferent populations, are common in the central nervous system. The dynamic and computation benefits of this organization are not fully understood. With their simple model, the authors were able to quantify the amount of topographic structure and selectivity in the network and study its impact on the network's steady-state. In particular, a bifurcation point suggests a qualitative difference between networks with and without sufficient topographic modularity.<br /> - The theoretical analysis in the paper is rigorous, and the mean-field study shows good agreement with computer simulations of the model.<br /> - The authors describe simulation results of networks with different dynamical properties, including rate-based networks, integrate-and-fire neurons, and more realistic conductance-based spiking neurons. All simulations exhibit similar qualitative behavior, supporting the conclusion that the behavior due to structural modularity will carry to more complex and biologically relevant neural dynamics.<br /> - Overall, the authors convince that the topographic structure of the network can lead to noise reduction, given that the input to the network is provided as distinct channels.

      Weaknesses:

      The authors support their hypothesis and show a relation between topographic connection and noise reduction in their model. However, I find the study limited and struggle to see the impact it will have on the field. The paper is purely theoretical; it does not provide any physiological evidence that supports the conclusion. On the other hand, and this is the key issue, I do not find real theoretical insights in this work. In the following, I elaborate on why I hold this opinion.

      - The hypothesis is that topographic projections in cortical areas allow faithful signal propagation. However, as the authors point out, reliable transmission can be achieved in other ways, such as by direct routing of information (lines 17-19). Furthermore, denoising can be accomplished by a simple feedforward network (e.g., ref 38) without E/I balance and with plasticity rules that do not require topographic connectivity. Thus, I find the computational model not well motivated.<br /> - The task studied here is a simple classification of static inputs: the efferent readout needs to identify the active channel. Again, this could be achieved by a single layer of simple binary neurons [Babadi and Sompolinsky 2014]. The recurrent connectivity and E/I balance suggest that dynamics should play an essential part in the model. However, the task is not well suited for understanding the role of dynamics.<br /> - The authors perform a mean-field study to explain how modularity affects signal propagation. At the heart of their argument is that the E/I network exhibit bistability. However, bistability can be achieved by an excitatory population with a threshold [Renart et al., 2013]. The role of the inhibitory population does not seem crucial for the task and questions the motivations for this analysis.<br /> - Active and inactive channels are decided by the two stable states of the network: the high and the low activity regimes. However, noise fluctuations and their propagation through the network may have a prominent role in the overall dynamics. I find that noise fluctuation analysis is bluntly missing in this work.<br /> - The main finding is a critical level of modularity, m=~0.83, above which the network shows denoising properties of silencing inactive channels and increasing the mean activity of active ones. However, the critical modularity is numerically demonstrated and is not derived theoretically. For a theoretical insight into this transition between denoising and mixing properties of the network, I would have liked to see a more rigorous discussion on the critical value. What does the critical point depend on? The authors show that the single-neuron dynamics do not affect the critical value, but what about other structural elements such as the relative efficacies of the E/I and the feedforward connectivity matrices? Do the authors suggest that m=0.83 is a universal number? I expect a more detailed analysis and discussion of this core issue in a theoretical paper.

      To conclude my main criticism, I believe that a theoretical paper should offer a more in-depth analysis and discussion of the core ideas presented and not rely mainly on simulations. For example, to provide theoretical insight, the authors should address central questions such as the origin of the critical modularity, the role of the recurrent balance connectivity, and how the network can facilitate computations other than winner-takes-all among channels. Alternatively, if the authors aim to describe a neural dynamics model without deep theoretical insights, I would expect to see physiological evidence supporting the suggested dynamics.

      Conclusions:

      The model studied by the authors is novel and provides a valuable way of exploring the effects of modularity and topographic connectivity on signal propagation through hierarchical recurrent neural networks. However, the study lacks theoretical insights into cortical circuit functions in its current version. I believe that for this work to impact the field, it needs to show further analysis and not rely on a numerical study of the model with limited theoretical derivations.

    1. Reviewer #1 (Public Review):

      This paper tests the hypothesis that 1/f exponent of LFP power spectrum reflects E-I balance in a rodent model and Parkinson's patients. The authors suggest that their findings fit with this hypothesis, but there are concerns about confirmation bias (elaborated on below) and potential methodological issues, despite the strength of incorporating data from both animal model and neurological patients.

      First, the frequency band used to fit the 1/f exponent varies between experiments and analyses, inviting concerns about potentially cherry-picking the data to fit with the prior hypothesis. The frequency band used for fitting the exponent was 30-100 Hz in Experiment 1 (rodent model), 40-90 Hz in Experiment 2 (PD, levodopa), and 10-50 Hz in Experiment 3 (PD, DBS). Ad-hoc reasons were given to justify these choices, such as " to avoid a spectral plateau starting > 50 Hz" in Experiment 3. However, at least in Experiment 3 (Fig. 3), if the frequency range was shifted to 1-10 Hz, the authors would have uncovered the opposite effect, where the exponent is smaller for DBS-on condition.

      Second, there are important, fine-grained features in the spectra that are ignored in the analyses, which confounds the interpretation.

      One salient example of this is Fig. 2, where based on the plots in B, one would expect that the power of beta-band oscillations to be higher in the Med-On condition, as the oscillatory peaks rise higher above the 1/f floor and reach the same amplitude level as the Med-OFF condition (in other words, similar total power is subtracted by a smaller 1/f power in the Med-ON condition). But this impression is opposite to the model-fitting results in C, where beta power is lower in the Med-ON condition.

      Another example is Fig. 1C, where the spectra for high and low STN spiking epochs are identical between 10 and 20 Hz, and the difference in higher frequency range could be well-explained by an overall increase of broadband gamma power (e.g. as observed in Manning et al., J Neurosci 2012, Ray & Maunsell PLoS Biol 2011). This increase of broadband gamma power is trivially expected, as broadband gamma power is tightly coupled with population spiking rate, which was used to define the two conditions.

      The above consideration also speaks to a major weakness of the general approach of considering the 1/f spectrum a monolithic spectrum that can be captured by a single exponent. As the authors' Fig. 1C shows, there are distinct frequency regions within the 1/f spectrum that have different slopes. Indeed, this tripartite shape of the 1/f spectrum, including a "knee" feature around 40-70 Hz which is well visible here, was described in multiple previous papers (Miller et al., PLoS Comput Biol 2009; He et al., Neuron 2010), and have been successfully modeled with a neural network model using biologically plausible mechanisms (Chaudhuri et al., Cereb Cortex, 2017). The neglect of these fine-grained features confounds the authors' model fitting, because an overall increase in the broadband gamma power - which can be explained straightforwardly by the change in population firing rates - can result in the exponent, fit over a larger spectral frequency region, to decrease. However, this is not due to the exponent actually changing, but the overall increase of power in a specific sub-frequency-region of the broadband 1/f activity.

    1. Reviewer #1 (Public Review):

      The manuscript by Vitet et al. reveals the role of the motor adaptor protein Huntingtin in regulating the pool of synaptic vesicles via its phosphorylation and binding to Kinesin-3 motor protein on one end and synaptic vesicle precursors on the other. The authors use both genetic models of mice harboring mutations in the HTT gene that either mimic constitutive phosphorylation of Huntingtin protein or a phospho-dead version of it. Despite previous reports suggesting no functional outcome for these mutations, using modified motor tests, the authors identified that constitutive phosphorylation of huntingtin impairs the motor skill learning of mice. Next, in a set of elegant and multidisciplinary methods, including electrophysiological recordings in acute slices, TEM imaging, knock-out rescue assay, and biochemical and in-vitro approaches, the authors suggest the mechanism for this dysfunction is through the accumulation of synaptic vesicles in the constitutive phosphorylation mode of huntingtin which increases the release probability and the corticostriatal network. The authors show that this accumulation is mediated by enhanced interaction between vesicular and phosphorylated huntingtin with Kinesin-3 motor proteins which drives the anterograde transport of synaptic vesicle precursors towards the axons and synaptic terminals.

      Altogether, this reviewer finds this manuscript well written, well performed, comprehensive and convincing. The new findings in this work are a fundamental addition to the understanding of both basic mechanisms of neuronal function, as well as their dysfunction in neurodegenerative diseases, in this case, Huntington's disease.

    1. Reviewer #1 (Public Review):

      In the current manuscript, scRNA data of the early "ventral nerve cord" and optic system of the adult brain are compared. The authors generated scRNAseq data for the embryo and integrated existing data sets from other labs and extracted repo-positive glial sets to present a description of the transcriptional landscape of glial cells. The main message of the paper is that morphological diversity among glial cells in a given class is not a strong predictor of transcriptional identity.

      However, the data on embryonic "ventral nerve cord" glia are generated from whole embryos, and even provided that the ventral nerve cord harbors 75% of all glia and thus the majority is ventral nerve cord, the data should not be called vnc-specific. The vnc-specific data set (adult CNS) that is already published (Allen et al., 2020) is strangely not even mentioned in the current manuscript. The idea of having a comprehensive description of glial transcriptional profiles is great - but I was missing the integration of the midline glial cells, which can be considered as ensheathing glial cells that - as the cortex glia - also express wrapper (Stork et al., 2009).

      Unfortunately, I found most of what is reported in this work not to be entirely new. The classification of glial diversity in the adult brain was presented by the Meinerzhagen and Gaul labs (Edwards and Meinertzhagen, 2010; Edwards et al., 2012; Kremer et al., 2017). The description of two astrocyte-like cell types is a reduction of data that defined three morphologically distinct astrocyte-like cells (Peco et al., 2016), which is not discussed. Some other aspects were ignored, too. Two other morphological distinct types of ensheathing glia exist, ensheathing glia and ensheathing/wrapping or track-associated glia were described but this is not discussed (Kremer et al., 2017; Peco et al., 2016).

    1. Reviewer #1 (Public Review):

      The authors show that metformin reduced the elevated intraocular pressure in mice with steroid-induced ocular hypertension and attenuated damage to the cytoskeleton of the ocular trabecular meshwork. In human trabecular meshwork cells, the authors showed that the protective effects of metformin against oxidative injury were exerted by regulating cytoskeleton remodeling through integrin/ROCK signals.

      Strengths of the paper include the rigorous methodology and support of the data for the conclusions. The work has the potential to advance glaucoma research but also the use of metformin for reversing other states of oxidative injury, such as fundamental aging mechanisms, in multiple tissues.

    1. Reviewer #1 (Public Review):

      Iyer et al. address the problem of how cells exposed to a graded but noisy morphogen concentration are able to infer their position reliably, in other words how the positional information of a realistic morphogen gradient is decoded through cell-autonomous ligand processing. The authors introduce a model of a ligand processing network involving multiple "branches" (receptor types) and "tiers" (compartments where ligand-bound receptors can be located). Receptor levels are allowed to vary with distance from the source independently of the morphogen concentration. All rates, except for the ligand binding and unbinding rates, are potentially under feedback control. The authors assume that the cells can infer their position from the output of the signalling network in an optimal way. The resulting parameter space is then explored to identify optimal "network architectures" and parameters, i.e. those that maximise the fidelity of the positional inference. The analysis shows how the presence of both specific and non-specific receptors, graded receptor expression and feedback loops can contribute to improving positional inference. These results are compared with known features of the Wnt signalling system in Drosophila wing imaginal disc.

      The authors are doing an interesting study of how feedback control of the signalling network reading a morphogen gradient can influence the precision of the read-out. The main strength of this work is the attention to the development of the mathematical framework. While the family of network architectures introduced here is not completely generic, there is enough flexibility to explore various features of realistic signalling systems. It is exciting to find that some network topologies are particularly efficient at reducing the noise in the morphogen gradient. The comparison with the Wnt system in Drosophila is also promising.

      Major comments:

      - The authors assume that the cell estimates its position through the maximum a posteriori estimate, Eq.(5), which is a well-defined mathematical object; it seems to us however that whether the cell is actually capable of performing this measurement is uncertain (it is an optimal measurement in some sense, but there is no guarantee that the cell is optimal in that respect). Notably, this entails evaluating p(theta), which is a probability distribution over the entire tissue, so this estimate can not be done with purely local measurements. Can the authors comment on this and how the conclusions would change if a different position measurement was performed?

      - One of the features of the signalling networks studied in the manuscript is the ability of the system to form a complex (termed a conjugated state, Q) made of two ligands L, one receptor and one non-signalling receptor. While there are clear examples of a single ligand binding to two signalling receptors (e.g. Bmps), are there also known situations where such a complex with two ligands, one receptor, and one non-signalling receptor can form? In the Wnt example (Fig. 10a), it is not clear what this complex would be? In general, it would be great to have a more extended discussion of how the model hypothesis for the signalling networks could relate to real systems.

      - The authors consider feedback on reaction rates - it would seem natural to also consider feedback on the total number of receptors; notably, since there are known examples of receptors transcriptionally down-regulated by their ligands (e.g. Dpp/Tkv)? Also it is not clear in insets such as in Fig. 7b, if the concentration plotted corresponds to the concentration of receptors bound to ligands?

      - The authors are clear about the fact that they consider the morphogen gradient to be fixed independently of the reaction network; however, that seems like a very strong assumption; in the Dpp morphogen gradient for instance over expression of the Tkv receptor leads to gradient shortening. Can the authors comment on this?

      - Fig. 10f is showing an exciting result on the change in endocytic gradient CV in the WT and in DN mutant of Garz. Can the authors check that the Wg morphogen gradient is not changing in these two conditions? And can they also show the original gradient, and not only its CV?

  2. Oct 2022
    1. Reviewer #1 (Public Review):

      Hyperactivation of WNT/b-catenin signaling has been implicated in cancer. How b-catenin enters the nucleus is not completely understood. Using a heterologous model system of budding yeast, authors find that nuclear translocation of b-catenin is mediated by Kap104, the orthologue of TPO1/2. Authors further showed that a PY like motif in the C-terminus of b-catenin binds TPO1 and serves as a nuclear localization signal (NLS). Mutation of the PY like motif or inhibition of TPO1/2 inhibits b-catenin mediated transcription. Overall, this is an interesting study. The evidence that the PY like motif can serve as a NLS in yeast is convincing. However, how much this motif contributes to nuclear localization of full-length b-catenin in mammalian cells is not clear. Authors have relied on transcription readout of b-catenin, which has many caveats. Direct measurement of the level of b-catenin in the nucleus is important.

    1. Reviewer #1 (Public Review):

      This manuscript reports the function of FIO1, a mammalian METTL16 homolog, in Arabidopsis. The authors found FIO1 affects early flower phenotype through regulating splicing via U6 m6A modification. This paper confirmed FIO1-mediated m6A methylation on U6 RNA, consistent with two recently published reports. The manuscript contains quite a thorough splicing analysis on how splicing is affected in the fio1 mutant where U6 m6A is absent, and a detailed explanation of how m6A could affect base pairing and secondary structure involving U6 at different temperatures.

      1. FLC mRNA can be m6A methylated. The authors appear to suggest the effect is secondary. More analysis and explanation are required. For instance the authors could measure m6A level on FLC in fio1 mutant, mta mutant, and compare it with that of wt.

      2. The authors used nanopore m6A sequencing to map m6A in mRNA from wt and fio1 mutant strains. I would suggest either RIP-seq or mass spectrometry measurement to confirm the loss of fio1 leads to limited mRNA m6A changes.

    1. Reviewer #1 (Public Review):

      In the article "Neuroendocrinology of the lung revealed by single cell RNA sequencing", Kuo et. al. described various aspects of pulmonary neuroendocrine cells (PNECs) including the scRNA-seq profile of one human lung carcinoid sample. Overall, although this manuscript does not have any specific storyline, it is informative and would be an asset for researchers exploring various new roles of PNECs.

      Major comments:<br /> The major concern about the work is most results are preliminary, and at a descriptive level, conclusions or sub-conclusions are derived from scRNA-seq analysis only, lacking in-depth functional analysis and validation in other methods or systems. There are many open-end results that have been predicted by the authors based on their scRNA-seq data analysis without functional validation. In order to give them a constructive roadmap, it would be better to investigate literature and put them in a potential or probable hypothesis by citing the available literature. This should be done in each section of the result part.<br /> The paper lacks a main theme or specific biology question to address. In addition, the description about the human lung carcinoid by scRNA-seq is somehow disconnected from the main study line. Also, these results are derived from the study on only one single patient, lacking statistical power.

    1. Reviewer #1 (Public Review):

      In this manuscript, Dhurandhar, Cecchi and Meyer present a model that aims to predict the discrimination performance of human subjects in an odor mixture discrimination task using low-dimensional features, which include intensity, pleasantness and a set of 19 semantic descriptors. Specifically, the authors aim to find a metric of odor mixture similarity in feature space that accurately captures similarity (or discriminability) as judged by human subjects. The semantic descriptors are obtained from a chemoinformatic model previously developed by the authors. A mixture's feature vector is defined as the average of the features of the individual components. A Mahalanobis distance is defined between two mixtures, whose parameters are fit using experimental data from Bushdid et al, Science, 2016 and applied to three other independent datasets. They show that the RMSE in prediction outperforms a previously published model in two of the datasets.

      Strengths:

      The idea to relate the embedding vector of individual odor components to the embedding of a mixture so as to predict mixture discrimination performance is novel and interesting.

      Weaknesses:

      1) The authors claims are not supported by the data presented in the Figures. A trivial model which predicts a constant can potentially achieve better predictive performance:

      It is difficult to gauge the performance of the model solely from the RMSE as the data and predictions are not plotted (except in a pooled format in Figure 4b, which is however masked by the density plot). The RMSE should at the minimum be compared to the standard deviation of the dataset and plotted as the fraction of variance unexplained. Without knowledge of the standard deviation of the experimental data, it is not possible to judge the quality of the prediction.

      An examination of the inset in Figure 2a and Figures 4 shows that the data spans from ~0.54 to ~0.75. Since this was quite comparable to the RMSE of ~0.17 obtained by the author's prediction, I examined the data from the four datasets provided as a supplement by the authors. It turns out that the standard deviations of the discrimination performance (the output variable) are: Bushdid 0.176, Ravia 0.144, Snitz1 0.124, Snitz2 0.119. As these numbers indicate, simply using the constant mean as a prediction will lead to an RMSE of 0.176 for the Bushdid dataset.

      This appears to contradict the Middle inset in Figure 2a, which seemingly looks like a good fit. Closer examination of the two plots shows that the experimental data in the two are not the same (note for example the two datapoints with y < 0.45 in the left plot which are absent in the right). Since the authors have not clarified in the caption whether this is an illustration or if it is actual data, it is unclear how to interpret this plot.

      2) The data transformations performed to obtain the mixture embedding vector seem arbitrary. For a mixture of 30 components (or even 10), this involves taking an average of 30 feature vectors, which will very likely average out. The authors should explain the rationale for taking the average and not for instance the most common descriptors that appears in the mixture components.

      3) Other comments - i) the authors use linear regression to model a classification task. The justification for this choice is not explained. ii) Although this is not primary data from the authors, the authors should perhaps comment on why the minimal performance is not chance level (33%) but instead around 50 percent, even when the percent overlap between the mixtures is close to 100%. Iii) The authors do not define the Direct model. How is the RMSE of the Direct model on the Ravia dataset (0.45) much larger than the standard deviation of the dataset (0.144)?

    1. Reviewer #1 (Public Review):

      The sequencing of a genome is the first step in identifying the functional regions of that genome. The identification of the regions that encode sequences that will become proteins (protein coding genes) is made complicated by the transcription of the DNA into multiple versions of RNA (isoforms) from the same genome locus. Often these RNA isoforms have different start and stop positions in the genome and also have different sequences (exons) that are used for the protein coding process. Taking advantage of considerable improvements in a recently developed computer algorithm that predicts the most stable three-dimensional (3D) folding of protein sequences (AlphaFold2) Sommer, et al describe a strategy to use this information to evaluate among the multiple isoforms generated by each gene. This approach provides additional information along with sequence conservation, synteny and other genes that are co-regulated that can potentially rank order among isoforms to aid in annotating the protein coding human transcriptome. This capability is needed in determining the boundaries, exon sequences, evolutionary relationships of genes to their ancestral homologues, gene function and the structural regions responsible for disease.

      A troubling issue of using this approach is pointed out by the authors themselves, namely, the fact that many functional genes express isoforms that make proteins with poor Local Distance Difference Test (pLDDT) scores. Thus, the 3D structures of a proteins arising from two different isoforms cannot be the only criteria used to identify the gene structure encoded in a locus. However, an isoform encoding a protein with a high pLDDT (estimated to be >80/100) is likely to help define at least a conservative set of boundaries and structures for the annotation for a gene. It would have been useful to have some overall estimate as to the false positive and negative rates of using this strategy. Without this information this approach while useful, could be considered an incremental improvement in the annotation process.

    1. Reviewer #1 (Public Review):

      The majority of polygenic scores have been developed in individuals of European descent and the analysis of the generalisability and applicability of these PRSes in diverse populations has hitherto been limited. In this study, the authors make an important contribution to addressing this gap by evaluating utility of common PRS, curated in the Polygenic Score (PGS) Catalog, in predicting the risk of the commonly diagnosed cancers with high genetic predisposition (breast, prostate, colorectal, and lung) in a prospective cohort comprising 21,694 participants of East Asian descent in Singapore.

      Two major strengths in this paper are that this is one of the largest prospective Asian cohorts with long term follow up data, and the authors have completed the evaluation of a large number of PRSes (although it should be pointed out that not all of which are independent of each other).

      However, the authors have only described the results of the best performing PRS and attempted to describe PRSes across 4 major common cancers as a group. In so doing, there is a missed opportunity to describe what lessons we might learn in the applicability of PRSes discovered in one population in another diverse population. In addition, it is not clear what benefits may be gleaned from the analysis of the PRSes as a group, rather than individually.

    1. Reviewer #1 (Public Review):

      This paper has significant strengths in taking a rich, quantitative, neurally-grounded approach to the development of human walking. It provides a rich empirical dataset of EMG and kinematic data at this challenging age, as well as sophisticated analyses of these data in terms of motor primitives, which are a concept that has recently been usefully applied to understanding human walking and its development.

      STRENGTHS

      It builds on emerging literature in this field and adds data at the key age of infancy-toddlerhood.

      It takes a longitudinal approach, sampling children at the ages of newborn, 3 months, and newly walking. This is still reasonably rare in developmental research and allows for a powerful, robust interpretation of data: the authors should be commended for taking this approach.

      WEAKNESSES

      Some aspects of the work could have been more clearly introduced. This includes neural aspects: the location of the CNS control centres at the spinal level, and which higher centres control them (e.g. brainstem); the justification for understanding primitives as modular (no cross-talk or feedback). It also includes developmental aspects: introducing the stepping reflex, and behavioural aspects of infant motor variability (e.g. Adolph, Hoch & Cole, TICS, 2018).

      The patterns relate to walking in a stereotypical manner, yet children's walking is full of skips, jumps, and climbs - both in relation to external obstacles and on even ground. Indeed, it is a challenge to get children to 'walk normally' in a lab. Thus, variability is in fact greater than is discussed here and this should be acknowledged.

      The analyses are based on a limited sample of the data. (1) I am not clear on what basis the coders selected cycles, and why 5 cycles were selected. (2) It is not clear why certain movement parameters (cycle duration and flexion/extension proportions) and not others (e.g. step length, double support time) were selected. In particular, it is not clear why the authors focus on temporal, rather than spatial, variability. (3) Some data are based on stepping, and some on kicking. Because it's not clear that these are really equivalent, and because there are small samples of each (n<10), it's not clear that there is enough data to allow us to come to strong conclusions. The sample size should be justified - on the basis of power analyses and/or previous work in this area (e.g. Dominici, Science, n=40). From the results, where p values often hover around p=0.06, the paper seems underpowered to detect a decrease in variability with age for stepping kinematics and primitives.

      There are some points of interpretation that could have been clearer, for example highlighting how one might distinguish between variability as incidental (motor noise) or purposeful (for exploration); and how studying the time around walking onset can contribute to the broader literature on this topic.

    1. Reviewer #1 (Public Review):

      The study focuses on the role of SLC38A5, a neutral amino acid transporter, in retinal angiogenesis. The authors show that Slc38a5 transporter is highly enriched in normal retinal vascular ECs, and upregulated in the ECs in pathogenic neoangiogenesis (the OIR model). Additionally, the authors show that Slc38a5 transcription is regulated by Wnt/β-catenin signaling and deletion of Slc38a5 in mice substantially delays retinal vascular development and suppresses pathological neovascularization in the OIR model by suppressing glutamine uptake and reducing VEGFR2 expression. The authors claim that SLC38A5 is a new metabolic regulator of retinal angiogenesis.

      The study is performed carefully and demonstrates clearly an important role for the transporter in retina angiogenesis. However, there are some concerns that need to be addressed as follows:

      1) The authors show that Slc38a5 is downregulated in the Lrp5-/- and Ndpy/- retinas (Fig 1A, B); however, there is a discrepancy in Slc38a5 expression levels in the control retinas. The expression of Slc38a5 in the WT retina goes down from P8-P12 and then plateaus through P17 (Fig. 1A). In contrast, in Fig.1B, the expression of Slc38a5 in the Ndpy/+ retina plateaus from P8-P12 and then goes up through P17. The authors need to establish better the temporal expression of the transporter in control (WT) retinas.

      2) While it's clear that Slc38a5 mRNA and protein expression is enriched in LCM-isolated retinal vessels, it's unclear whether that expression is exclusively in ECs or also in vessel associated mural cells (Fig.1C, Fig.S1). Although Fig.S1 shows the mining of mouse retinal scRNA-seq database to demonstrate exclusive Slc38a5 expression in ECs, it's necessary to validate that in the tissue using either RNA in situ hybridization or IHC for in combination with an endothelial cell or mural cell marker.

      3) Fig.3: The image qualities are poor. The authors need to enhance image qualities to show the vessels clearly in such low magnification.

      4) Fig.3F: The images in this panel show more than 50% decrease in the vascular area in the deep plexus between WT and Slc38a5-/- retinas. However, the graph shows a far lower (10-15% at best) decrease in the vascular coverage. The authors need to select representative images to match the graph.

      5) The authors show the presence of vessels in the adult Slc38a5-/- retina to claim that vascular abnormalities seen in early development are gone in the adult (Fig. S2). However, the presence of vessels does not mean that there are no vascular abnormalities. The authors should compare established vascular parameters such as branching-density, vascular pruning between adult WT and Slc38a5-/- retinas to justify the claim.

      6) While the authors show that there is a decrease in pathological neovascularization in the Slc38a5-/- retina at P17 in the OIR model (Fig4), they do not mention what happens to the Slc38a5-/- retina at P12 immediately after the hyperoxia phase. Is the vaso-obliteration altered in the Slc38a5-/- retina at that time compared to the WT?

      7) What happens to the neurovascular unit (pericyte, astrocyte, Müller glia etc) in the Slc38a5-/- retina? How do they respond to altered angiogenesis?

      8) Overall, the Discussion needs to emphasize the role of endothelial cell metabolisms in vascular development and maturation and how Slc38a5 may influence these processes.

    1. Reviewer #1 (Public Review):

      The core question addressed by this study is whether right IFC damage disrupts stop-signal task performance because it plays a key role in response inhibition per se, or because it is crucial for attending to the need to engage response inhibition. A relatively large sample of patients with damage including right IFC, as well as lesioned and healthy control groups, were assessed on the stop-signal task accompanied by scalp EEG. The behavioral data were analyzed using hierarchical Bayesian modeling. Right IFC damage was associated with more trials where 'stopping' was not initiated, while an EEG hallmark of inhibitory control was present in trials where stopping initiation did occur, arguing that rIFG damage disrupts attention to the stop signal, rather than the inhibition that follows.

      This is an interesting study testing a well-defined hypothesis relevant to competing views of the brain basis of inhibitory control. The experimental design is sophisticated and the analysis was preregistered. The acquisition of both behavioral and EEG data in lesion patients provides converging evidence and supports causal inference.

      Interpretation of the results hinges on accepting that a hierarchical Bayesian model is appropriate for discriminating trials where stopping was 'triggered' from trials where there was no trigger. Likewise, we need to accept the EEG frontal beta burst pattern is an indicator of response inhibition. Both of these methodological elements have support from existing literature, although I don't think either of these has been applied in chronic focal lesion patients, so there may be technical issues to consider in their interpretation. Finally, as with most human lesion studies, caution should be applied in interpreting the critical lesion location: in this sample, the effects might relate to insula damage, or to white matter disruption within the ventrolateral/lateral frontal lobe or between those regions and subcortical regions. However, these provisos do not detract from the key finding that damage somewhere in these areas affected initiation/attentional processes rather than response control per se.

      The results are more consistent with an attentional account of right IFG (or more broadly, right ventral frontal lobe) contributions to stop-signal task performance; this is provocative in light of current views of prefrontal contributions to inhibitory control, although in line with a wider literature implicating right frontoparietal circuitry in selective attention. As the authors suggest, a sharp distinction between attention and inhibition may be somewhat artificial: these processes may be closely interrelated in speeded tasks requiring response interruption. However, the present study cleverly tackles the challenge of disentangling them, applying recent modeling and EEG distinctions with interesting results.

      The findings are helpful in further sharpening ideas regarding the neural basis of response control. They also have potential theoretical implications and perhaps direct experimental application in clinical-applied research on disorders of inhibitory control.

    1. Reviewer #1 (Public Review):

      The authors report data consistent with a new and unanticipated phenomenon: that Cre or its mRNA may be transmitted between tissues in the mouse. The epididymis appears to be the most common beneficiary of such transport from neural, and some other, tissues. The authors show this in two ways. First, they infect brains with AAV expressing Cre. They see expression of TdTomato in epididymis, from a construct that cannot express unless a loxP-flanked STOP cassette is recombined out. Second, because viral spread is a possible confounding artifact of AAV delivery, the authors also show that transgenes that drive Cre expression in the nervous system or elsewhere can cause TdTomato expression in the epididymis. They rule out that TdTomato is itself transmitted to the epididymis by showing that recombination occurred in the epididymis of the TdTomato-expressing mice.

      I believe that the authors saw what they report. The data are beautiful and convincing, the experimental design was excellent in every sense, including the use of multiple alternative Cre lines, viruses, or methods. The expression of TdTomato in the epididymis and sometimes elsewhere was unambiguous, and using PCRs to validate editing in TdTomato expressing cells clinched the case.

      What I am less sure of is the interpretation. The creative idea that Cre or its RNA can move between tissues in mouse would be extremely important for future technical exploitation and for demonstrating a previously un-considered complication to interpreting mouse reverse-genetic results. But as the authors note, both experiments to show this have potential caveats: AAV could escape into the circulation and go to other tissues, and promoter-Cre fusions can have leaky expression outside their expected expression zone. The authors argue, appropriately, that these most likely artifacts in the two experiment types differ, so one would have to posit that both types of artifacts occur. But this is not impossible.

      I was thus excited for the parabiosis experiment, as it was the perfect way to settle the issue. The choice of strains to link in this way was ideal. Unfortunately, the sample size was small and the results were mixed: 1 of 3 cases showed a result consistent with the authors' hypothesis. Further experiments involving injection of exosomes or serum were similarly suggestive but not conclusive.

      The clear and convincing data are a warning to mouse researchers about an unexpected complication of Cre-mediated gene manipulation. The data presented are consistent with the most interesting model, that Cre or its RNA can be transmitted between tissues, but additional data would make this conclusion unassailable.

    1. Reviewer #1 (Public Review):

      Jeong and coauthors demonstrate that eukaryotic type II topoisomerases undergo liquid-liquid phase separation (LLPS) under physiological conditions, and that the outcome of type II topoisomerase activity on supercoiled plasmid DNA is altered within condensates. The authors used budding yeast (Saccharomyces cerevisiae) topoisomerase II (scTopoII) to demonstrate LLPS and explore the dependence of LLPS on protein concentration, DNA concentration, and both the presence and phosphorylation sate of the unstructured C-terminal domains (CTDs) of scTopoII. Crucially, the authors verify the fluid-like behavior of the condensates, confirming coalescence of drops directly, and establishing exchange between condensed droplets and the aqueous phase via FRAP experiments. The condensates form under nominally physiological conditions, but the critical concentration decreases significantly when DNA exceeding 100 base pairs is included. As expected, the condensates can be solubilized with increasing salt or DNA concentrations. Based on established phase condensation prediction algorithms, the authors identify the CTDs of the yeast and two human isoforms of topo II as the most likely protein elements driving LLPS. They expand on this prediction by performing a useful alignment of several representative eukaryotic topo II enzymes, which reveals low homology but conservation of disorder and high frequencies of charged amino acids, both of which contribute to LLPS. The authors confirm the importance of the CTDs in LLPS by demonstrating that isolated CTDs can form condensates under a more limited set of conditions than the WT protein, whereas removing the CTDs from scTopoII inhibited LLPS altogether. In contrast, phosphorylation of the CTDs altered the biophysical properties of the condensates (fluidity for example) but not affect the propensity to form condensates. By employing a 2.9 kb negatively supercoiled DNA as the condensation scaffold and adding ATP to the condensates, the authors could measure the effects of LLPS on topo II activity. They demonstrate convincingly that topo II activity is driven towards catenation of circular DNA in condensates with full length topo II and interestingly towards the formation of knotted substrates when comparable concentrations of scTopoII lacking the CTDs was used. The authors round our this elegant work by comparing the results obtained with scTopoII with the two human isoforms hsTopoIIα and hsTopoIIβ. Together these results indicate that eukaryotic topo II enzymes can phase separate with DNA under physiological conditions and that this process can change the outcome of the strand passage reaction catalyzed by the type II enzymes. These findings help explain previous results demonstrating linking and knotting of closed circular DNA by high concentrations of type II topoisomerases in vitro, and may help unravel the roles of these enzymes in both promoting and resolving chromosome entanglements in vivo.

      The main thing that others may criticize is the lack of the demonstration of LLPS and its role in vivo, but I think their findings, especially the different activities under LLPS permissive and inhibitory conditions, stand on their own.

      The experiments are clear and compelling and the results support the conclusions of the study. The finding of different morphological states with plasmid DNA under some conditions is interesting and should be more fully investigated to understand the nature of this different structure that may be more relevant in vivo than the more conventional condensates observed with short DNA substrates.

    1. Reviewer #1 (Public Review):

      This study performs an interesting analysis of evolutionary variation and integration in forelimb/hand bone shapes in relation to functional and developmental variation along the proximo-distal axis. They found expected patterns of evolutionary shape variation along the proximo-distal axis but less expected patterns of shape integration. This study provides a strong follow-up to previous studies on mammal forelimb variation, adding and testing interesting hypotheses with an impressive dataset. However, this study could better highlight the relevance of this work beyond mammalian forelimbs. The study primarily cites and discusses mammalian limb studies, despite the relevance of the suggested findings beyond mammals and forelimbs. Furthermore, relevant work exists in other tetrapod clades and structures related to later-developing traits and proximo-distal variation. Finally, variations in bone size and shape along the proximo-distal axis could be affecting evolutionary patterns found here and it would be great to make sure they are not influencing the analysis/results.

    1. Reviewer #1 (Public Review):

      Gu et al. examine how activity in the substantia nigra pars reticulata (SNr) contributes to proactive inhibition - the suppression of upcoming actions - by recording SNr activity in rats performing a task requiring them to be prepared to cancel a planned movement. This task was developed in a previous study by the same authors in which they examined how globus pallidus pars externa (GPe) activity depends on proactive inhibition (Gu et al., 2020), which motivated the present focus on SNr. The task is rich and the complementary analyses of how the neural activity relates to the behavior, at the level of individual neurons and populations, are appropriate and illuminating. Overall, this study is well done and has the potential to be a nice contribution to our understanding of how the SNr, and therefore the basal ganglia, mediate behavioral inhibition. Addressing a few questions, however, would improve the paper.

      - It is not obvious why the presence or absence of proactive inhibition should be determined on a session-by-session basis. It seems quite possible that proactive inhibition is not an all-or-none phenomenon, and also that it might be exhibited to a greater or lesser extent across a session (e.g., due to changes in motivational drive). It would therefore strengthen the paper to better explain the rationale for comparing neural activity across entire sessions "with" and "without" proactive inhibition. Within-session variation in proactive inhibition could be quite advantageous, allowing for within-neuron comparisons. It is even possible that the differences in neural activity that the authors report here using session-by-session analysis are an underestimate of the true effect of proactive inhibition.

      - It is difficult to rule out alternative explanations for the observed differences in SNr activity. While the authors acknowledge this point in the 3rd paragraph of the discussion, they only discuss one potential alternative - reward expectation. Another difference between maybe-stop and no-stop trials is the likelihood that a particular target should be selected, which has also been shown to modulate SNr activity (Basso & Wurtz, 2002). As is often the case with complex behavioral tasks, there may be many other differences between trial types that may contribute to differences in neural activity. It would be helpful for the authors to more fully explain how their results relate to contextual modulation of SNr activity, and why the dependence of SNr activity on proactive inhibition may be a novel finding.

      - A natural question arising from this study, as with most studies of neural recordings during behavior, is the causal nature of the neural activity. It would be non-trivial and beyond the scope of the current study to perform the sort of perturbations that could determine whether population variability causally relates to preparation to suppress actions. But it would be useful to discuss future experiments that might be able to test causality.

    1. Reviewer #1 (Public Review):

      Einarsson et al have produced CAGE data from EBV-immortalised lymphoblastoid cells from more than a hundred individuals from two genetically diverse African populations (YRI and LWK), and used it to study how sequence variation affects the activity of promoters at the level of expression variability and at the level of transcription start site usage within promoters across individuals.

      The dataset is very exciting, and the analyses were performed carefully and described well. The results show that promoters in the genome vary a lot with respect to their expression variability across individuals and that their level of variability is closely associated with their biological function and their sequence and architectural features. These results are often confirmatory - it is well established that promoters have different architectures associated with different sequence elements, different types of gene regulation and even differences across individual cells. In general, the multifarious observations boil down to one key distinction:

      - Regulated genes have promoters that look and act differently from those of housekeeping genes.

      While this is unsurprising, the authors then proceed to analyse other underlying differences between low variability (mostly housekeeping) and high variability (overwhelmingly regulated) promoters. Several observations have alternative and sometimes more elegant explanations if some of the previously worked out properties of housekeeping vs regulated promoters are taken into consideration:

      - The authors are keen to interpret the architectural features of ubiquitously expressed (housekeeping) promoters as selected for robustness against mutations in ensuring stable and steady expression levels. However, there are some known facts about both housekeeping and regulated promoters that make alternative interpretations plausible.

      - When discussing broad promoters, the authors disregard the well known fact that the most commonly used transcription start positions are those with YR sequence at (-1,+1) position. Any mutation within the span of broad promoter cluster that removes an existing YR or introduces a new one has the capacity to change both the TSS distribution pattern and overall level of expression of that promoter - but only slightly. This way, broad promoters can be viewed as adaptation not for robustness but for ability to take many mutations with small effect size that will drive any _positive_ selection smoothly across a changing fitness landscape.<br /> - Indeed, the main property of low variability promoters is that there isn't a single nucleotide change (either substitution or indel) that can substantially change their activity. (In that they are clearly different from e.g. TATA-dependent promoters, where one change can abolish TBP binding or deprive the promoter of a YR dinucleotide at a suitable distance from the TATA box.) This is achieved by their dependence on broad and weak sequence signatures such as GC composition and nucleosome positioning signal. However, most such genes are not known to have a strict requirement for dosage control. On the contrary, dosage seems to be much more critical for the functional classes that in the authors' analysis show variable expression.<br /> - Whether it is a removal of YR dinucleotide, introduction of a new one, or the change of nucleosome positioning, it seems that the transcription level from housekeeping, low variability promoters is unaffected, or at least affected mildly enough that it is not within the statistical power of the CAGE data across different individuals to detect the difference. Rather than robustness, it can be interpreted as competition - the architecture recruits preinitiation complex at a fairly constant rate, and it is the different YR positions that "compete" for serving as transcription initiation position, with the CAGE signal reflecting the relative effectiveness of each position in that competition. If one of the YR dinucleotides is removed, often the other, neighbouring ones will be used instead. The same might happen for potential multiple nucleosome positioning signals - if one becomes less efficient at stopping a nucleosome, another will be used more often.<br /> - The fact that decomposed parts of housekeeping promoters add up to approximately the same expression level across individuals even when they are uncorrelated point that they might actually be anticorrelated - indeed, the UFSP2 plot in Figure 4E looks like the two decomposed promoters are anticorrelated. That would argue against the independence of the decomposed promoters - indeed it may again point to "competition" where the decrease in use of one will simply shift most initiation events to the other.<br /> - In general, not everything is a result of direct evolutionary selection, and that is what should have clear landmarks of purifying selection. On the contrary, promoters, especially housekeeping promoters, have vastly different nucleotide and dinucleotide compositions across Metazoa, both at large and at relatively short distances, which means they can undergo concerted evolution as a group, which means they should be "robust" to mutations in a way that allows them to change much more and more rapidly than some other promoter architectures - especially TATA-dependent architectures whose key elements and spacing between them haven't substantially changed for more than a billion years, and possibly longer.

      - While housekeeping promoters are broad but mostly not among the broadest, regulated promoters can be either broad or narrow. This is also known - while narrow promoters are overrepresented for tissue-specific and non-CGI promoters, promoters of Polycomb-bound developmental genes are often broad and have large CpG islands; the latter may account for some of the broadest CAGE clusters observed in the data. It would be an interesting finding if both TATA-dependent and developmental promoters were found to be variable across individuals in a non-trivial way (the trivial way being the variability due to larger dynamic range of their expression - e.g. the expression of SIX3 in many cell types is basically zero, while the dynamic range of RPL26L1 is very limited) - this should be checked by analysing them separately.

      - While broad promoters can be decomposed into subclusters with differential expression across individuals, the authors do not seem to allow for the decomposition of intertwined TSS positions within the cluster, but rather postulate hard boundaries between subclusters. This is different from e.g. overlapping maternal and zygotic promoter use (Haberle et al Nature 2014), where the distribution of the used TSS positions is different but the clusters can overlap.

      - Both Dreos et al (PLOS Comp Biol 2016) and Haberle et al. (2014) show that one stable element of a broad promoter is the positioning signal of its first downstream nucleosome. As seen very convincingly in both Drosophila and zebrafish, the dominant TSS position of the broad promoter is highly predictive of the position of first downstream nucleosome and its underlying positioning sequence, and the most plausible interpretation is that there is an "optimal" distance from nucleosome for transcriptional initiation, resulting in the dominant (i.e. most often used) TSS position. In mammals, broad promoters are even broader than in those two species and might have multiple nucleosome positioning signals they can use. In such cases, mutations in one of the nucleosome positioning signals, or indels changing the spacing between the nucleosome and the part of sequence that contains TSS, might lead to differential use of one nucleosome signal vs other. This would be compatible with the authors' observations in low variability promoters that decomposed promoters are used to different extends in different individuals.

      - If we were to look for sources of difference other than the actual sequence architecture, some differences between regulated and unregulated promoters can be explained by the key difference: the regulation of regulated genes comes from outside the core promoter; the regulation of housekeeping genes is largely dependent on the intrinsic activity of the core promoter itself. This way, for example, in the absence of a causative variant in the promoter itself, the observed variability in the SIX3 promoter might not be encoded in the promoter itself - instead, enhancer responsiveness might be encoded in the promoter, and the variability itself could be due an enhancer that can be hundreds of kilobases away. Such a scenario combined with broad promoter would likely result in decomposed promoters that are highly correlated across individuals - because they are both externally controlled by the same regulatory inputs.

    1. Reviewer #1 (Public Review):

      This work characterizes at the mechanistic level the relationship between ER stress and the lack of glycosylation of two seipin mutants observed in seipinopathy, N152S and S154L (nomenclature of the long form of seipin). In short, the authors find that lack of glycosylation (ngSeipin) decreases ER calcium levels, and that it does so in an aggregation-dependent way, with no effect at low protein expression (or when oligomerization is impeded) and a significant effect (also leading to apoptosis) when high amounts of non-glycosylated seipin are expressed in the cell. The authors show that this causes ER stress, using BiP, XBP1 and CHOP as markers, and that this is attenuated when SERCA2b is overexpressed. They also identify the C-terminus of seipin as the region directly interacting with SERCA2b.

      The work is carefully described, with extensive controls, and the conclusions are supported by the data presented. In addition, the results have important consequences in several fields. First, they clarify the relationship between ER stress and nerurodegenerative diseases in general, and seipinopathy in particular. Second, by identifying the mechanism through which seipin and SERCA2b interact, they raise interesting mechanistic considerations about the relationship between lipid accumulation and calcium homeostasis; third, they hint at potential therapeutic approaches for ER-stress associated neurodegenerative diseases.

      Weaknesses

      The major weakness of this work is that it lacks an assessment of the relevance of the findings in vivo. This originates from two issues. First, the phenotype observed depends on the amount of non-glycosylated protein, and the investigation of the amount of protein in different cell types (especially neurons) is beyond the scope of this work. Also, the use of a double mutant (N152S, S154L) rather than of two single mutants (that are clinically relevant) makes a direct comparison with the pathological scenario quite difficult.

      In addition, the authors describe that in glycosylated seipin, deletion of the N-terminus and modification of the TM helices has a very large effect on ER calcium levels (Figure 6C), but no mechanistic explanation for this observation is provided.

    1. Reviewer #1 (Public Review):

      Dingus J et al investigated an important technical issue with the use of single domain antibodies (nanobodies) as intracellularly expressed proteins to probe cellular biology. Over the past decade, the relative simplicity and stability of nanobodies compared to conventional antibodies has led to many interesting uses of these molecules as either sensors or means to perturb intracellular protein function. Many have generally assumed that the increased stability of nanobodies enables them to be expressed in a functional form within the reducing environment of the cytoplasm. With an observation that many nanobodies are actually not stable within the cytoplasm, the authors aimed to determine the sequence determinants of what drives stability/instability, and then devised strategies to rescue folding of unstable nanobodies in the cytosol. They first looked at 75 nanobodies and use a fluorescence based metric to determine which nanobodies are stable and unstable. This revealed a set of residues that are enriched in either category. With a further strategy to determine consensus changes for stability, the authors rescued the stability of a large fraction of unstable nanobodies. Further analysis allowed the authors to whittle down to a few mutations that are important for stability, with some structural considerations in mind. In further important experiments, the authors show that these rescuing mutations generally do not destroy antigen binding. Importantly, they clearly highlight a few examples where the stability rescue strategy impairs antigen binding. Finally, experiments in retinal cells and bacteria support the success of this strategy.

      The overall manuscript is well presented with clear data and appropriate caveats included throughout the work.

    1. Reviewer #1 (Public Review):

      This paper describes the structure of an N-terminus OB-fold of the 70kD subunit of human replication protein A (RPA70N) bound to a peptide from five different proteins; HELB, ATRIP, BLM (two peptides), RMI1, and WRN, which are involved in various DNA transactions. This study of X-ray crystallography revealed a structural basis of RPA70N OB-fold for weak interactions with Kd of 10-18 uM. Importantly, distinct binding modes of RPA70N to different substrates indicate the flexible nature of this domain in the recognition of binding partners. In addition, the authors characterized the role of a critical hydrophobic residue in the peptides on the interactions to RPA70N by Isothermal titration calorimetry (ITC). The structural analysis of RPA70N with 6 different binding peptides is impressive and the results described in the paper support the main conclusion. Understanding the structural flexibility of the RPA70N domain is important to know the molecular mechanisms of how RPA regulates distinct DNA transaction pathways. On the other hand, the authors need some in vivo functional assays to support their conclusion.

    1. Reviewer #1 (Public Review):

      Kohler and Murray present high-throughput image-based measurements of how low-copy F plasmids move (segregate) inside E. coli cell. This active segregation ensures that each daughter cell inherit equal share of the plasmids. Previous work by different labs has shown that faithful F-plasmid segregation (as well as segregation of many other low-copy plasmids, segregation of chromosomes in many bacterial species and segregation of come supramolecular complexes) require ParA and ParB proteins (or proteins similar to them) and is achieved by an active transport mechanism. ParB is known to bind to the cargo (plasmid) and ParA forms a dimer upon ATP binding that binds to DNA (chromosome) non-specifically and also can bind to ParB (associated with cargo). After ATP hydrolysis (stimulated by the interaction with ParB), ParA dimer dissociates to monomers and from ParB and the chromosome. While different mechanisms of the ParA-dependent active transport had been proposed, recently two mechanisms become most popular - one based on the elastic dynamics of the chromatin (Lim et al. eLife 2014, Surovtsev PNAS 2016, Hu et al Biophys.J 2017, Schumaher Dev.Cell 2017) and the other based on a theoretically-derived "chemophoretic" force (Sugawara & Kaneko Biophysics 2011, Walter et al. Phys.Rev.Lett. 2017).

      The authors start by following motion of F plasmid with one or two plasmids per cell and by analyzing plasmid spatial distribution, plasmid displacement (referred to as velocity) as a function of their relative position, and autocorrelations of the position and the displacement. They concluded that these metrics are consistent with 'true positioning' (i.e. average displacement is biased toward the target position - center for one plasmid and 1/4 and 3/4 positions for two plasmids ) but not with 'approximate positioning' (i.e. when plasmid moves around target position, for example, in near-oscillatory fashion). This 'true positioning' can be described as a particle moving on the over-dampened spring. They reproduce this behavior by expanding the previous model for 'DNA-relay' mechanism (Lim et al. eLife 2014, Surovtsev PNAS 2016), in which plasmid is actively moved by the elastic force from the chromosome and ParA serves to transmit this force from the chromosome to the plasmid. Now, the authors explicitly consider in the model that the chromosome-bound ParA can diffuse (which the authors refer as 'hopping') and this allows the model to achieve 'true plasmid positioning' for some combination of model parameters in addition to oscillatory dynamics reported in the original paper (Surovtsev PNAS 2016).

      Based on their computational model, the authors proposed that two parameters, diffusion scale of ParA = 2(2Dh/kd)1/2/L (typical length diffused by ParA before dissociation) and ratio of ParB-dependent and independent hydrolysis rates = kh/kd are key control parameters defining what qualitative behavior is observed - random diffusion, near-oscillatory behavior, or overdamped spring ('true positioning'). They vary this two parameters ~30- fold and ~200-fold range by changing Dh and kh respectively, to illustrate how dynamics of the system changes between these 3 modes of motion. While these parameters clearly play important role, the drawback is that the authors did not put either theoretical reasoning why these parameters are truly governing or showed it by varying other model parameters (kh, number of ParA NParA, spring constant of chromosome k, diffusion coefficient of the plasmid Dp) to show that only these combinations define the type of the system behavior. The authors qualitative analysis on importance of relies on the steady state solution for the diffusion equation for ParA. It is really unfortunate that no ParA distribution was measured simultaneously with the plasmid motion, as this would allow to compare experimental ParA profiles to expected quasi-steady-state solutions.

      The authors also show by simulations that overdamped spring dynamics can transition into oscillatory behavior when decreases, for example by cell growth. Indeed, they observed more oscillatory behavior when they compared single-plasmid dynamics in the longer cells compared to the shorter cells. This was not the case in double-plasmid cells, in eprfect agreement with their analysis. They also calculated ATP consumption in the model and concluded that the system operates close but below (perhaps, "above" should be used as it refers to bigger) the threshold to oscillatory regime which minimize ATP consumption. While ATP consumption analysis is very intriguing, this statement (Abstract Ln24-25) seems at odds with the authors own analysis that another ParA-dependent plasmid system, pB171, operates mostly in oscillatory regime, and it is actually for this regime the authors' analysis suggest minimal ATP-consumption (Fig. 8).

      I think the real strength of the paper is that it can potentially to show that if one considers that the intracellular cargo can be moved by the fluctuating chromosome via ParA-mediated attachments, then various dynamics can be achieved depending on combinations of several control parameters (plasmid diffusion coefficient, ParA diffusion coefficient, rate of hydrolysis and so on) including previously reported 'oscillations' (Surovtsev PNAS 2016), 'local excursions' (Hu et al Biophys.J 2017) and 'true positioning' (Schumaher Dev.Cell 2017). The main drawback (in this reviewer opinion) that this is obscured by the current presentation and discussion of this work and previous modelling work on ParA-dependent systems. For example, instead of using "unifying" potential of the presented model, yet another name 'relay and hopping' is used in addition to previously used 'DNA-relay', 'Brownian ratchet', 'Flux-based positioning', and it appears that the presented model is an alternative to these previously published work. And only in model description (in Methods section) one can find that the "... model is an extension of the previous DNA-relay model (Surovtsev et al., 2016a) that incorporates hopping and basal hydrolysis of ParA and uses analytic expressions for the fluctuations rather than a second order approximation"(p.17, ln15-17). While it is of course the authors right to decide how to name their model, it should be explicitly clear to the reader what is a real conceptual difference between presented and previous models from the abstract, introduction and discussion section of the paper, not from the "fine-print" details in the supplementary materials. This would allow to avoid unnecessary confusion (especially for the readers not directly involved into the modelling of ParA/B system) and clarify that all these models rely on the elastic behavior of fluctuating chromosome to drive active transport of the cargo. This reviewer believes that more explicit discussion on the models (one from the authors and previously published) differences and similarities will help with our understanding of how ParA-dependent system operate. This discussion should also include works on PomXYZ system, in which it was shown that similar dynamic system can lead to specific positioning within the cell (Schumaher Dev.Cell 2017, Kober et al. Biophys.J 2019). This will may it explicit that the models results have direct impact beyond the ParA-dependent plasmid segregation.

      I think that expanded parameter analysis, and explicit model comparison/discussion will make the contribution of this work to the field more clear and with the potential to advance our general understanding of how the same underlying mechanism can lead to various modes of intracellular dynamics and patterning depending on parameters combination.

    1. Reviewer #1 (Public Review):

      In this manuscript by Ramaprasad et al., the authors report on the functional characterization of the P. falciparum glycerophosphodiesterase to assess its role in phospholipid biosynthesis and development of asexual stages of the parasite. The authors utilized loxP strategy to conditionally knock-out the target gene, they also carried out complementation assays to show recovery of the knock-out parasites. They further show that Choline supplementation is also able to rescue the knock-out phenotype. Quantitative lipidomic analyses show effect on majority of membrane phospholipids. In vitro activity assays and metabolic labelling assays shows role of GDPD in metabolism of exogenous lysoPC for PC synthesis. The manuscript deciphers the functional role of an important component of lipid metabolism and phospholipid synthesis in the parasite, which are crucial metabolic pathways required for replication of the parasite in the host cell.

    1. Reviewer #1 (Public Review):

      This work sheds light on the adverse effects of Bacillus thuringiensis, a strong pathogenic bacteria used as a microbial pesticide to kill lepidopteran larvae that threaten crops, on gut homeostasis of non-susceptible organisms. By using the Drosophila melanogaster as a non-susceptible organism model, this paper reveals the mechanisms by which the bacteria disrupt gut homeostasis. Authors combined the use of different genetic tools and Western blot experiments to successfully demonstrate that bacterial protoxins are released and activated throughout the fly gut after ingestion and influence intestinal stem cell proliferation and intestinal cell differentiation. This phenomenon relies on the interaction of activated protoxins with specific components of adherens junctions within the intestinal epithelium. Due to conserved mechanisms governing intestinal cell differentiation, this work could be the starting point for further studies in mammals.

      The conclusions proposed by the authors are in general well supported by the data. However, some improvements in data representation, as well as additional key control experiments, would be needed to further reinforce some key points of the paper.

      1) Figure 1 and others: Several graphs in the manuscript show the number of cells/20000µm2.<br /> How is the shape of the gut in the different conditions studied in this manuscript?<br /> The gut shape (shrunk gut versus normal gut for example) could influence the number of cells seen in a small area. For example, the number of total cells quantified in a small area (here 20000µm2) of a shrunk gut can be increased while their size decrease. As a result, the quantification of a specific cell type in a small region (here 20000µm2) can be biased and not represent the real number of cells present in the whole posterior part of the R4 region. Would it make sense to calculate a ratio "number of X cells/number of DAPI positive cells per 20000µm2"?

      2) Figure 4: Is it possible that Arm staining is less intense between ISC and progenitors after ingestion of the bacteria due to the fact there is a high rate of stem cell proliferation? Could it be an indirect effect of stem cell proliferation rather than the binding of the toxins to Cadherins?<br /> Could the authors use the ReDDM system to distinguish between "old" and newly formed cells? This could be a good control to make sure that the signal is quantified in similar cells between the control and the different conditions.

      Figure 4E' and 4G': Arm staining seems more intense when looking at the whole membrane levels of cells compared to control. Is it possible that the measured ratio contact intensity/membrane intensity presented in Figure 4I could be impacted and not reflect the real contact intensity between ISC and progenitor cells?<br /> What is the hypothesis of the authors about the decrease of Arm or DE-Cad seen after bacterial/crystal ingestion? Does the interaction between the toxins and DE-Cad induce a relocation of DE-Cad?

      The authors should add more details about the way to quantify in the Material and methods section. How many cells have been quantified per intestine? How did they choose the cells where they quantified the contact intensity?..etc

      Figure 4B, D, F and H: How did the authors recognize the ISCs? Could the authors do quantifications of DE-Cad signal? Like Arm staining, the staining seems stronger at the whole membrane level in F and H compared to the control.

      3) Figure 5: How is the stem cell proliferation upon overexpression of DE-Cad in control or upon bacteria/crystals ingestion? Do the authors think that the decrease of Pros+RFP+ new cells upon overexpression of DE-Cad could result from a decrease of stem cell proliferation?<br /> Did the authors quantify the % of new ECs in the context of overexpression of DE-Cad?<br /> Figure 5F: As asked before, did the authors distinguish the signal between newly born cells and the signal between older cells?

      The same experiments (stem cell proliferation + quantification of the % of new ECs) could be also done when authors overexpress of the Connectin, supplemental figure 5. This would be another control to conclude that the effects on cell differentiation are specific due to the interaction between DE-Cad and the toxins.

      In the "crystals" condition, the overexpression of Connection seems to partially rescue the increase % of new Pros+RFP+ new cells observed in Figure 3F (Figure S5I compared to Figure 3F).

    1. Reviewer #1 (Public Review):

      Modular E3 ligase complexes play important roles in controlling cell proliferation and differentiation. As had been illustrated by Cullin-RING-ligase complexes that are associated at specific stages of neuronal differentiation, regulated formation of E3 ligase complexes can strongly impact cell fate specification, but only very few examples of such regulation have been reported. Whether E3 ligase composition impacts the global proteome is not known. Providing additional examples of E3 ligase complexes, whose composition is regulated during differentiation processes, would be an important contribution to our understanding of how the ubiquitin system controls cell fate.

      In this manuscript, Sherpa and coworkers used quantitative proteomics in in vitro models of erythrocyte differentiation to discover changes in the composition of the CTLH E3 ligase. Rather than finding altered association of substrate adaptors, including GID4, the authors noted the exchange of the scaffold subunits RanBP9 and RanBP10. Structural analyses suggested that this exchange does not have major impacts on CTHL conformation, but may lead to a reduction in E3 ligase activity towards a model substrate. The authors also deleted the enzymatic CTLH subunit MAEA and the E2 UBE2H from cell lines that served as in vitro models of erythrocyte differentiation. They found that loss of MAEA caused a strong decrease in UBE2H, which interestingly required the catalytic activity of CTLH. This observation suggested that CTLH complex composition is actively regulated. The loss of CTLH activity led to an increase protein abundance of hemoglobin subunits and accelerated erythrocyte differentiation, suggesting that CTLH might restrict cell fate specification until proper signals have been received by precursor cells.

      While the observation of altered CTLH composition during differentiation is interesting, this study does not establish whether it is functionally important. The authors should assess whether deletion of RanBP9 or RanBP10 has functional consequences onto erythrocyte differentiation, which would indicate that the observations made here are significant in the context of this differentiation program. Furthermore, how MAEA loss causes a depletion in UBE2H has not been addressed beyond a simple rescue experiment using a single MAEA mutant, and the specificity and importance of this regulatory circuit therefore remains somewhat unclear. I do believe that especially the first issue needs to be addressed by the authors in order to establish the importance of the findings reported in this manuscript.

    1. Reviewer #1 (Public Review):

      Shade et al. describe the endocast and semicircular canal of multiple individuals and ontogenetic stages belonging to the taxon Europasaurus. Investigation of these traits lead the authors to suggest that this dwarfed sauropod was precocial and potentially capable to communicate with other individuals of the same species.

      Overall, I enjoyed the manuscript, because of the importance of the taxon and the gap in our knowledge that this study fills. The anatomical descriptions of the endocast and semicircular canal are well done and detailed. That being said, the manuscript can be improved in terms of comparative framework: in the current version, the manuscript only covers anatomical comparisons in the discussion. I would suggest the authors include a final figure showing multiple endocasts of other sauropodomorphs to better show the evolutionary morphological transitions affecting the endocast and semicircular canal in this clade. It would also be useful to have tables with measurements comparing hearing frequencies among non-avian dinosaurs with Europasaurus: is this taxon peculiar in this? Or is it in the range of other taxa? Finally, the fact that vocalization was possible in this taxon does not imply gregarious behavior: this should be specified better in the manuscript.

    1. Reviewer #1 (Public Review):

      The authors use the nanobody tools generated in the companion manuscript and have combined them with DNA-Paint oligonucleotide labeling to generate super-resolution images of indirect flight muscles. Using this approach, they could map the precise organization of the different domains from the two giant titin-like fly homologs called Sallimus and Projectin against which the nanobodies had been raised with a precision ranging from 1 nm to 4 nm, depending on the distance between them. They show that in indirect flight muscles the N-ter of Sallimus is located within 50 nm of the Z-disc, and that its C-ter reaches the A-band roughly 100 nm away from the Z-disc. Likewise, they show that the N-ter of Projectin colocalizes with the C-ter of Sallimus at the edge of the A-band, whereas its C-ter is located about 250 nm away in the A-band and 350 nm from the Z-disc. It overall suggests a staggered and linear organization of both proteins with a potential area of overlap spanning 10-12 nm, that Sallimus could bridge the Z-disc to the A-band acting as a ruler, while Projectin should only overlap with 15% of the A-band and possibly a 10 nm of the I-band.

      The value of this work comes from its use of advanced technologies (DNA-Paint + super-resolution). The biological conclusions confirm and refine earlier and recent papers, especially EM papers and the impressive and very comprehensive JCB paper by Szikora et al in 2020, although the conclusions of the present work differ somewhat from those of Szikora who had predicted that Sallimus does not reach the A-band. That aspect could have been better discussed.

    1. Reviewer #1 (Public Review):

      Hepatitis C virus (HCV) infection continues to be an enormous global public health problem with over 70 million infected. The advent of all-oral direct-acting antivirals (DAAs) has transformed the landscape of HCV therapy and paved the path to the ambitious World Health Organization (WHO) goal of viral hepatitis elimination by 2030. Research to establish an algorithm to shorten DAA therapy duration while maintaining high cure rates would impact both treatment access and achieving HCV elimination. The current clinical study aimed to examine a response-guided therapy (RGT) algorithm to shorten the standard 12-week sofosbuvir and daclatasvir therapy based on measuring hepatitis C viral load level at day 2 of treatment. The authors managed to complete this study despite severe COVID-19-related restrictions. While the RGT algorithm failed to reach acceptable cure rates under the 4-week treatment arm, the study provides valuable kinetic data to test other RGT approaches. Also, this paper is novel since data on HCV RNA genotype 6 kinetics is lacking.

    1. Reviewer #1 (Public Review):

      Using multiple mouse models with varying levels of H19 and Igf2 expression, the authors dissect the role of H19 and Igf2 in cardiac and placental development. Severe cardiac defects and placental anomalies were found to be correlated with the extent of H19/Igf2 dysregulation. Transcriptomic analysis revealed that H19/Igf2 dysregulation disrupts pathways related to extracellular matrix (ECM) and proliferation of endothelial cells. This work links the heart and placenta through regulation by H19 and Igf2, demonstrating that an accurate dosage of both H19 and Igf2 is critical for normal embryonic development, especially related to the cardiac-placental axis. The topic is of significance and the data are of high quality.

    1. Reviewer #1 (Public Review):

      The work is largely based on metabolic flux assays of cultured cells, using a combination of metabolite concentration assessments, stable isotope-labeled substrates coupled with mass spectrometry, mathematical modeling, and cell proliferation analysis. The work finds a significant and unexpected phenotype in lung fibroblasts and smooth muscle cells of decreased lactate production in hypoxia which is important in the field of pulmonary hypertension. The evidence is strong and could be assisted with further orthogonal studies.

    1. Reviewer #1 (Public Review):

      This excellent manuscript challenged the premise that NF-kappaB and its upstream kinase IKKbeta play a role in muscle atrophy following tenotomy. Two animal models were used - one leading to enhanced muscle-specific NF-kappaB activation and the other a muscle-specific deletion. In both models, there was no significant relationship to observed muscle changes following tenotomy. Overall this work is significant in that it challenges the existing dogma that NF-kappaB plays a crucial role in muscle atrophy.

      Surprisingly the authors noted that there were basal differences observed in the phenotypes of their models that were sex-dependent. They note that male mice lose more muscle mass after tenotomy and specifically type 2b fiber loss.

      Overall this is an outstanding study that challenges the notion that NF-kappaB inhibitors are likely to improve muscle outcomes following injuries such as rotator cuff tears. Its main weakness is that there were no pharmacological arms of investigation; this fails to definitively exclude the hypothesis that inhibition may exert some effect in healing, perhaps in surrounding non-muscle matrix tissue that in turn may assist in healing.

    1. Reviewer #1 (Public Review):

      This paper makes two major contributions. First, the authors provide a large synthetic dataset of human arm trajectories tracing the alphabet in 3D space. They also model the musculoskeletal system and the muscle spindles during tracing. This dataset would be very valuable for later studies. I thank the authors for making the effort.

      Second, the authors train various neural networks on two tasks, a character trajectory-decoding task and an action recognition task, from spindle outputs and find that artificial neural network representations from the action-recognition task better explain what is known about the proprioceptive system. This is potentially an important finding, because, the authors claim that trajectory decoding is the canonical hypothesis for proprioception's role.

      The authors are very systematic in the methodology with which they did their machine learning and representational analysis. I don't have any major comments on that.

      I have concerns about the main finding though. While it is true that state estimation is thought to be a major function of proprioception, this state estimation is part of a control loop. If the goal is to refute the canonical hypothesis for proprioception, the authors should actually simulate/train a full control loop. This is likely to change their conclusions because authors interpret state prediction as the prediction of end effector coordinates at each time step. However, to run a control system one may need to predict other state variables - like effector velocities and accelerations, muscle configurations, etc. - as well, and these may change the intermediate level representations.

    1. Reviewer #1 (Public Review):

      In this well-written manuscript, Afshar et al demonstrated the significant transcriptional and proteomic differences between cultured human umbilical vein endothelial cells (HUVECs) and those freshly isolated from the cords. They showed that TGFbeta and BMP signaling target genes were enriched in cord cells compared to those in culture. Extracellular matrix (ECM) and cell cycle-related genes were also different between the two conditions. Because master regulators of EC shear stress response genes, KLF2 and KLF4, were downregulated in culture, the authors sought to restore the in vivo transcriptional profile with the application of shear stress in an orbital shaker and dextran-containing media for various time periods. They showed that after 48 hours of shear stress the transcriptional profile of sheared cells correlated with in vivo transcriptional profile more significantly than static cultures. They also showed, using single cell RNAseq, that EC-smooth muscle cell cocultures resulted in changes in TGFbeta and NOTCH signaling pathways and rescued 9% of the in vivo transcriptional signatures.

      This is an important study that was elegantly executed. The authors should also be commended for making their data public; thereby, creating a valuable resource for vascular biologists.

    1. Reviewer #1 (Public Review):

      The authors seek to quantify SARS-CoV-2 viral kinetics and address the question of whether this varies with variant, vaccination status, previous exposure, symptom status or age. The results are supported by two independent analyses. A first analysis based on a logistic regression that models the probability of having a cycle threshold (Ct) value <= 30 on each day post-detection. A second analysis that uses a semi-mechanistic model that describes viral proliferation and clearance (using Ct value as a proxy) with a 2-piece linear function.

      The authors find small, but clear differences in SARS-CoV-2 clearance times related to several factors. They show that for Omicron infections, boosted individuals have longer clearance times than non-boosted individuals. When further stratifying by pre-booster antibody titer, they found that boosted individuals with low antibody titers had a slowest clearance, and non-boosted individuals with high antibody titers had a quickest clearance. These results are slightly confounded by age, given that boosted individuals were generally older than non-boosted ones, and younger Omicron-infected individuals had higher antibody titers than older Omicron-infected individuals, but the trends were consistent in the sensitivity and subgroup analysis. Overall, the conclusions are supported by the data analysis.

      Given the changing epidemiology of SARS-CoV-2, it is important to continue to estimate viral kinetics and clearance times to adapt isolation policies accordingly. I agree with the claim of the authors that these results may support a change from time-based policies of isolation to test-based ones.

      The strengths of the manuscript are the quality of the data, with a high sampling frequency, the choice of the statistical models, and the sensitivity analysis conducted. An inevitable weakness is that the population is not representative of the whole population (acknowledged in the manuscript). In this regard, a bit more information about the population of the study in the introduction would be appreciated.

      I very much liked the results for the viral kinetics model. The viral kinetics model allows to differentiate the duration of the two phases (proliferation and clearance) as well as the peak viral RNA, thus giving a more precise picture of the attributes of the viral trajectory that vary as a function of different factors. I found the procedure and the results for this model easier to interpret than the results from the logistic regression.

    1. Reviewer #1 (Public Review):

      The authors studied the dynamics of dynamic multicellular response and the cell-cell interaction networks after PNS injury. This is the first longitudinal study that has been carried out in such detail. It also includes a comparative analysis between circulating immune cells in peripheral blood, and in the injured nerve. They performed a follow-up using flow cytometry, ELISA, in situ hybridization, and immunofluorescence labeling of nerve sections. In addition, they compared the role of Wallerian degeneration in this process by using the Sarm1-/- mutant mice. The authors show how immune cells get metabolically reprogrammed after nerve injury, how the distal and proximal compartments react differentially, and how the cell interactions change during injury and resolution. The authors show great biological knowledge in the analyses of their data. This is a great resource for scientists working on the PNS or regeneration in general. To facilitate excess to their data the authors provided a web tool.

    1. Reviewer #1 (Public Review):

      In this paper, the authors first examined how the spontaneous bursts of activity in the optic tectum of zebrafish arise from the excitatory and inhibitory connectivity patterns between tectal neurons. Toward this goal, they recorded spontaneous activity patterns of tectal neurons using large-scale calcium imaging and fitted a simple model to the data to estimate parameters of hypothetical connectivities. They claim that a uniform distribution of fast, short-range excitatory connections and slow, long-range inhibitory connections across tectal populations are sufficient to replicate several aspects of spontaneous burst dynamics.

      Based on this finding, the authors further examined the role of model-estimated network states in sensory perceptions and eye convergence behavior for prey capture. Their series of experiments show that the proposed slow, long-range inhibitory connections may underlie sensory habituations for spatially specific visual stimuli and resulting eye convergence behavior for prey capture. Their experiments also show that spontaneous dynamics drive spontaneous eye convergence behavior. Based on these results, the authors propose underlying mechanisms of spontaneous activity bursts in the optic tectum and their behavioral significance.

      The major strength of the paper is that it found a critical role of inhibitory connectivities between tectal neurons in sensory adaptation and its behavioral consequences based on both statistical modeling and experiments. The model-driven estimation of neural connectivity is rigorous and will likely set the standard for future works in optic tectum research. The major weakness of the paper is its organization of messages in the abstract and the discussion. It would be challenging for readers to understand what is the main take-home message. There are also claims in the discussion that went beyond what their results can support and may result in unnecessary drawbacks from peers in the field. I advise the authors to revise these sections so that the reader can better understand the significance of the paper and how it contributes to the progress in the research field.

      The authors' experiments and analyses convincingly support their main claims. Their findings will likely contribute to a better understanding of how excitatory and inhibitory connectivities develop in the optic tectum of zebrafish and how such connectivities play critical roles in sensory perception and behaviors.

      This work sits on insights from the recent studies that described the emergence of spontaneous neural assemblies in the optic tectum and the visual habituation behavior of zebrafish. The optic tectum is one of the most studied regions in the zebrafish brain and is an excellent model for understanding these universal neural phenomena observed across animal taxa. I am convinced that the insights from this paper will further stimulate community efforts.

    1. Reviewer #1 (Public Review):

      This manuscript by McCafferty et al. presents the integrative computational structural modelling of the IFT-A complex, which is important to proper cilium organelle formation in eukaryotic cells. Recent advances in protein structure prediction (AlphaFold) allowed the authors to model the structures of the 6 individual subunits of the IFT-A complex. Interactions between IFT-A proteins were experimentally investigated by purifying Tetrahymena cilia, isolating IFT complexes, and utilizing chemical crosslinking and mass spectrometry (MS). In addition, the authors present a somewhat improved 23Å cryo-electron tomography (cryo-ET) map of the IFT-A complex (previously determined cryo-ET structures of IFT trains have resolutions of 24-40Å). Integrative modelling using the predicted structures of the 6 IFT-A proteins and the experimental data as restraints allows the authors to present a structural model for the entire IFT-A complex. This model is analysed in the context of the polymeric IFT train structure, interactions with the IFT-B complex, and the structural position of ciliopathy disease variants.

      This is in principle a timely and interesting study that attempts to push the limits of structural modelling of large protein complexes using structure prediction in combination with experimental data. Unfortunately, the study has several shortcomings and the data providing restraints for the integrative modelling are not optimal.

      1) Chemical crosslinking and MS were used to obtain both intra-molecular crosslinks used to validate the structural models of the individual IFT-A proteins as well as inter-molecular crosslinks used as restraints in the structural modelling of the hexameric IFT-A complex. It is mentioned on p. 4, line 9, that IFT-A complexes were enriched from the flagellar lysate M+M fractions using SEC and that fractions from SEC containing IFT-A complexes were crosslinked for MS analysis. However, the authors do not show the data for this sample, neither SEC profiles, SDS-PAGE nor data of the cross-linked samples. On p. 7 the authors write that their SEC profile corresponds to monomeric IFT-A, but this is not shown anywhere in the manuscript. The reason this is so important is that the IFT-A complex assembles into linear polymeric structures together with the IFT-B complex as so-called IFT trains in cilia. Data obtained from isolated IFT trains would thus have additional crosslinks between subunits in neighbouring IFT-A complexes that, if used to restrain the position of subunits within a hexameric IFT-A complex, would likely result in a wrong architecture. The fact that the authors also observe crosslinks between IFT-A and IFT-B proteins strongly suggests that they indeed carried out the crosslinking experiment on polymeric rather than monomeric IFT complexes.

      2) Given that the crosslink/MS data are unlikely to provide sufficient restraints for IFT-A structure assembly (and may even be misleading), the cryo-ET data become increasingly important. Unfortunately, the 23Å cryo-ET map does not provide sufficient detail to unambiguously fit domains of the IFT-A subunits as several of these have similar architectures consisting of WD-repeats followed by TPRs.

      3) Two preprints of the IFT-A structure appeared over the last few weeks. Hesketh et al., (https://www.biorxiv.org/content/10.1101/2022.08.09.503213v1) have obtained a single particle cryo-EM structure of the human IFT-A complex at 3.5Å resolution for the IFT121/122/139 part of the complex providing amino acids side-chain information. In addition, Lacey et al. (https://www.biorxiv.org/content/10.1101/2022.08.01.502329v1) provide a 10-18Å resolution cryo-ET structure of the Chlamydomonas IFT trains containing both IFT-A and IFT-B. It is noteworthy that the model outlined in the current manuscript is very different from the IFT-A models of Hesketh et al., and Lacey et al. (the Lacey et al. manuscript by the way shares an author with the McCafferty et al., manuscript). In both Hesketh et al., and Lacey et al. the IFT121 and IFT122 subunits interact via the N-terminal WD-repeats and the C-terminal TPRs with the beta-propellers (WD-repeats) positioned parallel and in close contact. In the model proposed by McCafferty, the beta-propellers of IFT121 and IFT122 are positioned far away from each other (>50Å) and are perpendicular to each other. Several other large discrepancies are found in the relative positions of IFT-A subunits. This suggests serious problems with the structural model of IFT-A proposed by McCafferty and needs to be addressed with great care.

      4) The authors observe crosslinks between the IFT-A proteins (IFT122 and IFT140) and IFT-B proteins (IFT70, IFT88, and IFT172) as discussed on pg. 6 and shown in figure 5A. To accommodate these crosslinks into the structural model of the IFT train shown in Figure 5A, the authors place the IFT-B subunits IFT70 and IFT88 far apart in the IFT-B complex. However, these subunits are known to interact directly (Taschner et al. JCB 2014) and indeed sit in proximity to the IFT train structure as observed by Lacey et al. While the crosslinking data may well be correct, the incorrect structural model of IFT-A likely forces an incorrect positioning of IFT-B proteins to fulfill the crosslinking data.

    1. Reviewer #1 (Public Review):

      It is a very interesting study that provides a clear and sophisticated description of the dynamic changes that take place at a calvaria defect site in terms of blood vessels, osteoblastic cells, and gradient of O2. It uses cutting-edge techniques. It is likely to become a critical reference for the scientific community.

      It is a descriptive paper, but the data are solid.

    1. Reviewer #1 (Public Review):

      In this paper by Moller et al. the authors investigate the basic cell biological processes by which microglia phagocytose apoptotic neurons. This is an important concept to investigate because it is well known that neural debris is produced and that microglia clear it, but little is known about how molecular mechanisms of how microglia phagocytose that debris. These authors utilize the strength of the zebrafish system to identify the microtubule dynamics are critical during a specific type of microglia phagocytosis. Then, the paper describes the molecular components that contribute to this microtubule-mediated process. The paper is excellent, with exceptional imaging and molecular manipulations that support an overall mechanistic pathway. It will be an important contribution to the microglia field and cited in future studies that investigate microglia efferocytosis.

    1. Reviewer #1 (Public Review):

      The manuscript by Himmel et al is an interesting study representing a topic of substantial interest to the somatosensory neurobiology community. Here, the authors use CIII peripheral neurons to investigate polymodality of sensory neurons. From vertebrates to invertebrates, this is a long-standing question in the field: how is it that the same class of sensory neurons that express receptors for myriad sensory modalities encode different behavioral responses. This system in Drosophila seems to be an intriguing system to study this question, making use of the genetic toolkit in the fly and ease of behavioral assays. In this study, the authors identify a number of channels that are important for cold nociception, and they showed that some of these do not appear to also encode mechanosensation. Despite my initial enthusiasm for this paper, halfway through, it felt as if I were reading two different papers that were loosely tied together. This lack of cohesion significantly reduced my enthusiasm for this work. Below are some of my criticisms:

      1. The first half of the paper is about a role for Anoctamins in cold nociception, but the second half switched somewhat abruptly to ncc69 and kcc. I assumed the authors would connect these genes in a genetic pathway, performing some kind of epistatic genetic interaction studies or even biochemical assays, and that this was the reason to switch the focus of the paper midway through. But this was not the case. Moreover, they performed a different constellation of experiments for the genes in the first half vs the second half of the paper (eg. Showed a role in cold nociception vs mechanosensation or showing phenotype from overexpression). This lack of cohesion made it difficult to follow the work.

      2. In Fig1B,C how does one confirm a CIII neuron is being analyzed. It might help the reader if there were at least some zoomed out photos where all the cell types are labeled and potentially compared to a schematic. Moreover, is there a CIII specific marker to use to co-stain for confirmation of neuron type?

      3. As this paper is predicated on detecting differences by behavioral phenotype, the scoring analysis is not as robust as it could be, especially considering the wealth of tools in Drosophila for mapping behaviors. The "CT" phenotype is begging for a richer behavioral quantification. This critique becomes relevant here when considering the optogenetic induced CT behavior in Fig5. If the authors were to use unbiased quantitative metrics to measure behavior, they could show how similar the opto behavior is to the natural cold evoked behavior. Perhaps the two are not the same, although loosely fitting under the umbrella of "CT".

      4. Following on from the last comment, the touch assays in Fig3 have a different measurement system from the other figures. Perhaps touch deficits would be identified with richer behavioral quantification. Moreover, do these RNAi larvae show any responses to noxious mechanical stimulation?

    1. Reviewer #1 (Public Review):

      This study characterizes interesting behavioral differences between the pest Drosophila Suzuki, and the well-studied fruit fly Drosophila melanogaster. D. Suzuki display a weaker preference for sugar-rich foods, and also prefer harder food substrates. The manuscript then investigates changes in electrophysiological responses to sugars, finding that some but not all sweet-sensing sensilla are lost. The authors also show reduced expression of several sweet-sensing gustatory receptors and increased expression of several mechanoreceptors in D. Suzuki. Additional studies are needed to determine whether physiological and molecular changes account for observed behavioral changes.

    1. Reviewer #1 (Public Review):

      The goal of this study was to investigate the mechanisms that lead to the release of photosynthetically fixed carbon from symbiotic dinoflagellate alga to their coral host. The experimental approach involved culturing free-living Brevolium sp dinoflagellates under "Normal" and "Low pH" conditions (respective target pH of 7.8 and 5.50) and measuring the following parameters: (Fig.1) cell growth rate over ~28 days, photosynthetic activity, glucose and galactose secretion at day 1; (Fig. 2) Cell clustering, external morphology (using SEM), and internal morphology (using TEM) after 3 weeks; (Fig. 3) Transcriptomic analyses at days 0 and 1; and (Fig. 4) glucose and galactose concentration in Normal culturing medium after 24h incubation with a putative cellulase inhibitor (PSG).

      The paper reports decreased growth at Low pH coupled with decreased photosynthetic rates and increased glucose and galactose release in 1-day Breviolum sp. cultures. At this same time point, genes related to cellulase were upregulated, and after 3 weeks morphological changes on the cell wall were reported. The addition of the cellulase inhibitor PSG to cells in pH 7.8 media decreased the release of glucose and galactose.

      The paper concludes that acidic conditions mimicking those reported for the coral symbiosome -the intracellular organelle that hosts the symbiotic algae- upregulate algal cellulases, which in turn degrade the algal cell wall releasing glucose and galactose that can be used as a source of food by the coral host. However, there are some methodological issues that hamper the interpretation of results and conclusions.

    1. Reviewer #1 (Public Review):

      Oberin, Petautschnig et. al investigated the developmental phenotypes that resulted from oocyte-specific loss of the EED (Embryonic Ectoderm Development) gene - a core component of the Polycomb repressive complex 2 (PRC2), which possess histone methyltransferase activity and catalyses trimethylation of histone H3 at lysine 27 (H3K27). The PRC2 complex plays essential roles in regulating chromatin structure, being an important regulator of cellular differentiation and development during embryogenesis. As novel findings, the authors find that PRC2-dependent programming in the oocyte, via loss of the core component EE2, causes placental hyperplasia and propose that the increase of placental transplacental flux of nutrients leads to fetal and postnatal overgrowth. At the mechanistic level, they show altered expression of genes previously implicated in placental hyperplasia phenotypes. They also establish interesting parallelism with the placental hyperplasia phenotype that is frequently observed in cloned mice.

      Strengths:

      The mouse breeding experiments are very well designed and are powerful to exclude potential confounding genetic effects on the developmental phenotypes that resulted from the loss of EED in oocytes. Another major strength is the developmental profiling across gestation, from pre-implantation to late gestation.

      Weaknesses:

      The evidence for 'oocyte' programming is restricted to phenotypic and gene expression analysis, without measurements of epigenetic dysregulation. It would be an added value if the authors could show evidence for altered H3K27me3 or DNA methylation in the placenta, for example.

      The claim that placental hyperplasia drives offspring catch-up growth is not supported by current experimental data. The authors do not address if transplacental flux is increased in the hyperplastic placentae, measure amino acids and glucose in fetal/maternal plasma, or perform tetraploid rescue experiments to ascertain the contribution of the placenta to growth phenotypes. Furthermore, it is unclear, from the current data, if the surface area for nutrient transport is actually increased in the hyperplastic placenta and the extent to which other cell populations (i.e. spongiotrophoblasts) are affected in addition to glycogen cells. In addition, one of the supporting conclusions that the placenta is a key contributor to fetal overgrowth is based on a very crude measurement - placenta efficiency - which the authors claim is increased in the homozygous mutants compared to controls. After analysing the data carefully, I find evidence for decreased placental efficiency instead. I believe that the authors mistakenly present the data as placenta to fetal weight ratios, which led to the misinterpretation of the 'efficiency' concept.

      The authors do not mention alternative explanations for the observed fetal catch-up and postnatal overgrowth. Why would oocyte epigenetic programming effects be restricted to the placenta, and not include fetal organs?

    1. Reviewer #1 (Public Review):

      This work addresses the mechanisms of transmembrane proteins TMEM87A and TMEM87B, which are thought to play a role in protein transport, but have been implicated in other processes as well, such as signaling and acting as mechanosensitive ion channels.

      The authors have determined a cryo-EM structure of human TMEM87A, finding that the protein consists of a Golgi-dynamics (GOLD) domain, sitting on top of a membrane spanning seven-transmembrane helical domains. The GOLD domain possesses a large cavity which is open to solution and the membrane. A related structure has been found for a protein Wntless known to promote membrane transport and secretion of the Wnt signaling proteins, and are lipid-modified.

      Based on this similarity, the authors propose TMEM87A and other GOLD domain proteins are involved in transport of other membrane-associated proteins, such as ghrelin and several cytokines. This is in contrast to the proposed roles of TMEM87 as a signaling or ion channel molecule. The authors report on no evidence of channel activity in reconstituted liposomes carrying the TMEM 87 protein. However, no target molecule has been identified.

      The work is based on a combination of Cryo-EM experiments and use of Alpha-fold-based prediction. It is competently done and the results are of interest to structural biologists. However, in the absence of a known target molecule of TMEM87A, a protein whose transport depends on TMEM87A, the results are of limited interest to a wider audience.

    1. Reviewer #1 (Public Review):

      This paper described in considerable detail the extension of the FIB milling technique to incorporate an in-chamber fluorescent light microscope that is coincident with the FIB and SEM beams. Existing instruments either rely on an external FLM system (requiring a specimen transfer step that may result in additional contamination) or an integral FLM that required cumbersome and inaccurate movement of the stage inside the SEM chamber. Coincident beams would thus be very welcome to all practitioners of the challenging art of making cryo lamella. While not novel in concept the authors had to develop several innovations inside the chamber to make all this work.

    1. Reviewer #1 (Public Review):

      This paper has many strengths that support its conclusions. Specifically, the use of natively expressed Piezo1 engineered to carry the HA tag allowed the authors to explore the distribution of the protein from primary cells isolated from a mouse at native expression levels. Thus, over-expression effects could be avoided. The super-resolution imaging is nicely controlled and convicting in its analysis of the distribution of the channel in 3D. The supporting EM data also supports the findings from fluorescence. Likewise, the theory is convincing in proving a mechanistic reason why the channel distributes into this region of the cell. While the data are quite nice and well analyzed, the paper is lacking in an exploration of what function this distribution of the channel would provide to the cell. Likewise, if this distribution was disturbed, would the red blood cell's behavior change? For example, would calcium signals in response to an osmotic challenge or squeezing change if the channel was not concentrated in the dimple? As it stands now, the paper presents a structural view of the distribution of piezo1 in a primary cell plasma membrane but lacks direct experimental evidence for the mechanism of this concentration or mechanistic insight into the effects of this spatial distribution on red blood cell physiology.

    1. Reviewer #1 (Public Review):

      This manuscript by Borssato et al describes atomic-level structural details of the central core domain of nonstructural protein 1 (Nsp1) of SARS-CoV-2, the virus responsible for the ongoing COVID-19 pandemic. Authors combined X-ray crystallography, fragment screening, computational modeling, and molecular dynamics simulation approaches to characterize potentially druggable pockets in Nsp1 core (aa 10-126). This study presents several notable strengths. For example, authors screened and tested 60 fragments from the Maybridge Ro3 library and solved a co-crystal structure of Nsp1 core with one such fragment 2E10 (N-(2,3-dihydro-1H-inden-5-yl)acetamide) to 1.1Å resolution. The molecular dynamics simulation and other computational experiments were performed rigorously.

      Nsp1 blocks the path of mRNA in ribosomes to modulate protein synthesis in the host cell. Nsp1 also binds the first stem-loop (SL1) of SARS-CoV-2 mRNA. The authors used a molecular docking program (HADDOCK) to build models of the Nsp1/RNA complex and predicted two modes of Nsp1 binding to SL1 RNA. A comparative structural analysis of Nsp1/2E10 experimental structure with Nsp1/SL1 (model) reveals that small molecule compounds occupying this site may block RNA binding of Nsp1. Given the established role of this interface in modulating the host and viral gene expression programs, this finding provides an important framework for designing the small molecules capable of completely blocking this interface.

      A weakness of this study is the lack of experimental validation of the two modes of Nsp1 binding to SL1 RNA.

    1. Reviewer #1 (Public Review):

      The authors introduced a dual chemical-induced reversible gene knockout method (CIRKO) using a reportable and reversible conditional intronic cassette (ReCOIN). They could use Cre to delete genes, and another recombinase Flp to recover genes. This would provide a means to reversibly control gene expression rather than deletion. Another strength of this system is that GFP is built in to allow investigators to see if the gene is inactivated or activated, thus monitoring gene status by visible fluorescence. The authors have used this method mainly in pig gene manipulation. It would be great if this system could also be tested in mouse genes, as Cre-loxP system for gene deletion is mostly used in mouse. Thus demonstration of this method in mouse gene manipulation would broaden its future application. Overall, this work provides a flexible gene switch system for in vitro and in vivo gene function study.

    1. Reviewer #1 (Public Review):

      This is a well-executed study using cutting-edge proteomics analysis to characterize muscle tissue from a genetically diverse mouse population. The use of only females in the study is a serious limitation that the authors acknowledge. The statistical methods, including protein quantification, QTL mapping, and trait correlation analysis are appropriate and include corrections for multiple testing. One concern is that missense variants, if they occur in peptides used to quantify proteins, could lead to false-positive signatures of low abundance (see lines 123-127). The experimental validation and deep dive into UFMylation provide some confidence in the reliability of other associations that can be mined from these data. The authors have provided a web-based tool for exploring the data.

    1. Reviewer #1 (Public Review):

      Overall, Long et al. very nicely show that the peel-1 locus gives a fitness benefit to strains independent of the zeel-1 gene. This famous TA element has been characterized solely for its role as a selfish genetic element, even though the original authors mused that it could have arisen because of a fitness benefit. This manuscript makes a valuable contribution by using both modeling and empirical results to show this point. The results have broad implications for the evolution of TA elements.

    1. Reviewer #1 (Public Review):

      This work by Shen et al. demonstrates a single molecule imaging method that can track the motions of individual protein molecules in dilute and condensed phases of protein solutions in vitro. The authors applied the method to determine the precise locations of individual molecules in 2D condensates, which show heterogeneity inside condensates. Using the time-series data, they could obtain the displacement distributions in both phases, and by assuming a two-state model of trapped and mobile states for the condensed phase, they could extract diffusion behaviors of both states. This approach was then applied to 3D condensate systems, and it was shown that the estimates from the model (i.e., mobile fraction and diffusion coefficients) are useful to quantitatively compare the motions inside condensates. The data can also be used to reconstruct the FRAP curves, which experimentally quantify the mobility of the protein solution.

      This work introduces an experimental method to track single molecules in a protein solution and analyzes the data based on a simple model. The simplicity of the model helps a clear understanding of the situation in a test tube, and I think that the model is quite useful in analyzing the condensate behaviors and it will benefit the field greatly. However, the manuscript in its current form fails to situate the work in the right context; many previous works are omitted in this manuscript, exaggerating the novelty of the work. Also, the two-state model is simple and useful, but I am concerned about the limits of the model. They extract the parameters from the experimental data by assuming the model. It is also likely that the molecules have a continuum between fully trapped and fully mobile states, and that this continuum model can also explain the experimental data well.

    1. Reviewer #1 (Public Review):

      Kidneys have very high energy needs and they preferentially use lipids as their energy source. Lipid metabolism however poorly understood in the kidney. Lipids accumulate in diseased kidneys, however the mechanism of lipid accumulation is not well understood. The team has studied lipid metabolism in the kidney.

      1. The team has first performed some basic lipid accumulation studies in kidneys of healthy mice. Lipid uptake show very significant feeding and fasting differences. It is unclear what stage of the feeding cycle the experiments were performed and whether the team has standardized it.

      2. All measurements have been performed using the colorimetric kit, the team should also use mass spec to validate results.

      3. The team did not measure lipolysis, fatty acid oxidation or fatty acid synthesis so statements so statements made around these pathways appear to be only speculative. They could measure it or adjust the text.

      4. Figure2 is probably the most valuable information in the paper. Lipid accumulation is only measured by staining. The team should also perform Plin stain or other methods to support their statement.

      5. The apical vs basal lipid update also seems speculative. I am not sure that we could see these differences. In addition, no quantification is presented to support the findings.

      6. For fatty acid uptake the team has analyzed the cd36 KO but not the fatp2 KO mice.

      7. The team has analyzed a PT injury model but most proteinuria is the result of glomerular injury. Unclear whether the data is relevant for glomerular disease

      8. The human urinary fatty acid quantification would need positive control samples. Clinically we often see lipid droplets in the urine, which is inconsistent with the presented data.

      9. No clear conclusion can be drawn from the data

      Overall while the project has some interesting elements and the presented data is relatively weak and no clear conclusion can be drawn and the overall message is unclear.

    1. Reviewer #1 (Public Review):

      Previous work, much of it by some of the authors, has characterized modification of various ion channels by SUMOYLation. However, there has been relatively little work exploring the effects of such modulation on function of neurons. This manuscript begins by showing quite large reciprocal effects of either enhancing or reducing SUMOYLation in layer 5 pyramidal neurons. One of the effects found is a leftward shift of the voltage-dependence of persistent sodium current. The authors then test the hypothesis that these changes result in part from SUMOYLation of Nav1.2 channels, and using a mouse engineered to eliminate Nav1.2 SUMOYLation, nicely show that modulation of Nav1.2 shifts the voltage-dependence of Nav1.2 and speeds back-propagation of action potentials from the AIS into the soma.

      The results in the manuscript are interesting, important, and convincing. Besides being important for describing effects of SUMOYLation on overall neuronal function, the selectivity of SUMOYLation for modifying Nav1.2 but not Nav1.6 channels - and the observation of slowing of back-propagation but not forward propagation from the AIS - adds to the previous data on the distinct functional roles of Nav1.2 and Nav1.6 channels in the AIS.

      It is puzzling that the authors focused so much on the effects of SUMOYLation on back-propagation and so little on the large effect on the frequency of firing, which seemed quite dramatic and potentially equally or more important for overall neuronal function than speeding back-propagation. In fact, after introducing the idea that the change in the f-I slope might reflect modulation of Na channels, there is little further discussion of the significance of the changes in firing frequency. Evidently, selective modulation of Nav1.2 channels but not Nav1.6 channels greatly affects firing. Is this explained only by the leftward shift of persistent sodium current from Nav1.2 channels? Or does the leftward shift of Nav1.2 channel gating affect spike threshold? Does modeling of selective modulation of Nav1.2 channels capture these changes in firing frequency and the slope of the f-I curve?

    1. Reviewer #1 (Public Review):

      Aguinagalde et al. investigated alternative treatment options for invasive pneumococcal diseases and considered the use of monoclonal antibodies to promote the killing of bacteria. For this to happen, complement deposition and activation are required to occur on the bacterial surface. The authors discovered that hexamerization of IgG strongly augments the recruitment of C1, and specific mutation of the antibodies can support this process and enable efficient phagocytosis and killing of bacteria by neutrophils. Further, sets of in vivo studies support the idea that passive immunization with these modified antibodies improves survival from pneumococcal pneumonia in mice.

      Considering vaccine-escape serotypes, the (sometimes) suboptimal vaccine response together with the increased occurrence of strains resistant to antibiotics, the search for alternative treatments is highly warranted, and this study is an excellent example supporting the use of therapeutic antibodies targeting the capsule.

      This study is generally very well performed and very well written. The authors conclusively show the importance of mAb hexamerization to augment complement deposition and activation on the surface of pneumococci, which promotes subsequent phagocytosis by neutrophils. Further experiments prove the importance of hexamerization of mAbs and the importance of this complement in the uptake of bacteria by neutrophils. Subsequent in vivo studies showed the therapeutic usefulness of modified antibodies in preventing mortality and bacteremia in female mice. All these data provide strong evidence for the claims of the authors.

      I noticed 2 weaknesses, the first related to the killing assays: considering that WT IgG less efficiently promotes complement-mediated phagocytosis of bacteria, one would assume that the ingested bacteria (to be killed) would be lower in neutrophils exposed to this IgG, to begin with - which is not accounted for in the analyses shown.

      A second weakness in my mind pertains to the in vivo experiment: the model used obviously requires a very high number of bacteria (the inoculum), somehow indicating that this specific bacterial strain does not lead to progressive infection (i.e. with replicating bacteria) but mice experience a severe acute inflammatory response followed by the rapid elimination of bacteria. This explains the high mortality - and indicates that mice succumb to acute inflammation, rather than the progressive replication of bacteria. To conclusively prove the therapeutic value of those modified antibodies, a clinically more relevant S. pneumoniae model would be helpful.

      A third aspect, which should be addressed in the discussion, unless tested and not shown, is how anti-pneumococcal IgM antibodies compare to hexamerized IgGs. Is there any advantage, or do they perform similarly with regards to complement activation?

    1. Reviewer #1 (Public Review):

      Histone peptides have been the primary tools for identification and characterization of histone readers. However, in vivo the real substates of histone readers are nucleosomes, in which histone tails exist in dynamic equilibrium between free, accessible state and DNA-bound, inaccessible states. Therefore, other histone modifications, particularly acetylation, impact the accessibility of histone tails to reader proteins. Using modified nucleosomes and known H3K4me3-binding PHD fingers, the authors show that indeed acetylation on nucleosomes has more profound impact than on histone peptide in terms of binding affinity and specificity, likely through increasing H3K4me3 accessibility. The authors further extend the study to investigate the impact of nucleosomal acetylation on H3K4 methyltransferase MLL1C's activity on nucleosome. Surprisingly, MLL1C shows no or very low level of enzymatic activity toward the unacetylated nucleosome, whereas H3 tr-acetylation strongly enhances H3K4 methylation by MLL1C, likely through increasing the accessibility of H3 tail to the enzyme. Consistent with this in vitro data, MS analysis of MCF-7 cells shows that increasing histone acetylation by HDAC inhibitor increases the global levels of H3K4 methylation, particularly on the histone tails with higher levels of acetylation. Together, these findings suggest a model in which acetylation releases nucleosome-bound H3 tails to available H3K4 methyltransferases for subsequent methylation and provide a molecular basis for the long-standing connection between H3 acetylation and H3K4 methylation.

      The effect of histone acetylation on histone tail accessibility to reader proteins have been previously reported by several groups, including studies from some of the authors of the current manuscript. The novelty of this study lies on the findings that tail accessibility also affects the enzymatic activity of H3K4 methyltransferases. However, additional evidence is needed to further strengthen the findings.

    1. Reviewer #1 (Public Review):

      This manuscript investigates the role of dopamine (DA) release in the dorsal bed nucleus of the stria terminalis (dBNST) investigating sign and goal tracking behavior, response to systemic fentanyl, and to fentanyl self-administration. The studies are largely well conducted and interesting, and the conclusions are justified by the data. The behavioral experiments are elegant and well-conceived, and good thought has been put into how they fit with current theories of learning and reinforcement. As written, however, it is hard to know how much of this data is novel as compared to what is known about DA release in the nucleus accumbens (NAc) which partially comes from similar sources (ventral tegmental area/VTA) but the BNST also receives DA from divergent sources (periaquaductal gray/PAG). The anatomy of DA innervation in the BNST is somewhat distinct and it is doubtful that the optical fiber has the spatial resolution to distinguish between areas that are innervated more by the VTA, which seems more restricted to the juxtacapsular subnucleus, vs. the PAG which more broadly innervates the dlBNST and the oval subnucleus. Further, the release of DA by these two areas may be differentially governed and that is not considered.

    1. Reviewer #1 (Public Review):

      Yanis Zekri et al have addressed an important question of the possible role of thyroid hormone (T3) and its nuclear receptor (TR) on local BAT thermogenesis and energy expenditure. In this well-written manuscript and well-carried work, the authors address the above question by A) by generating the BATKO mice by selectively eliminating TR signaling in BAT by knocking-in a TRα1L400R, a dominant negative version of the TRa1 receptor, and by floxing the ThRb gene. They characterized this mouse thoroughly to show that they totally lacked T3 responsiveness. Using qPCR they evaluated the selective abrogation of Thrb and Hr expression in BAT tissue relative to other tissue sites. B) Using time-course transcriptome analysis they then go on to enlist all the T3/TR direct target genes using well-defined criteria and further linking with their ChipSeq data they identified 639 putative target genes which are under the direct control of T3/TR signaling. Interestingly their gene analysis lead them to some target genes directly involved with UCP1 and PGC1α in addition to genes of many other metabolic processes related to BAT thermogenesis. The experiments on denervated BAT on wild-type PTU-fed was a rather neat experiment to eliminate the influence of noradrenergic terminal BAT target genes. Furthermore, the cold exposure experiments and the high-fat diets feeding with the series of complex analyses led them to the conclusion that BAT KO animals suffered from reduced efficiency of BAT adaptive thermogenesis. By comparing the BAT transcriptome of BATKO and CTRL mice after 24h at 4{degree sign}C, the authors further go on to show how BAT TR signaling controls other subsets of genes, especially a wide variety of metabolic regulations, especially lipolysis/fatty acid oxidation. Finally, EdU injection experiments showed a direct effect of T3 on BAT proliferation.

      I think it was well thought and well-designed study for understanding the complex action of cell-autonomous T3 regulation of adaptive thermogenesis. The conclusions of this paper are well supported by the data provided.

    1. Reviewer #1 (Public Review):

      This work addresses a long-standing question about how tolerance develops at the presynaptic level. That the number of receptors is unchanged following the treatment of animals with opioids was known since the early work using receptor binding assays. The conclusion was that receptor/effector coupling was disrupted was thought to be the primary mechanism underlying tolerance. This work indicates that the location of receptors is critically important in the development of tolerance. This work is groundbreaking and a game changer in the understanding of tolerance at the cellular level.

    1. Reviewer #1 (Public Review):

      In this paper, the authors investigate how a large loom-sensitive neuron in grasshoppers becomes sensitive to looming light objects (ON looms) and looming dark objects (OFF looms). They use different visual stimuli, calcium imaging, electrophysiology, and pharmacology to identify how ON and OFF looms each elicit responses in this large neuron.

      This topic is important because the segregation of visual signals into ON and OFF channels is fundamental to visual processing, yet these signals must typically be recombined to yield useful visual signals. How and where this happens remains of interest across visual systems. This study finds that, interestingly, ON looms are integrated into the neural response via a pathway that does not retain retinotopic information. The authors suggest potential energetic and functional advantages for the observed arrangement of dendritic integration.

      The strength of this paper is in its dissection of the mechanisms of dendritic integration and in its surprising findings. The major weakness in this paper is that when the authors perform detailed modeling of the neural response, they do not provide enough information to evaluate their results. They make some strong arguments about energetic favorability of different synaptic arrangements, which are also not explained in enough detail.

    1. Reviewer #1 (Public Review):

      Abdel-Hag, Reem et al. investigated the beneficial effects of a fiber-rich diet in the pathology of α-synuclein overexpressing (ASO) mice, a preclinical model of Parkinson's disease. They found that a prebiotic intervention attenuates motor deficits and reduces microglial reactivity in the substantia nigra and striatum. They extended these findings by doing scRNA sequencing, and they identified the expansion of a protective disease-associated microglia (DAM), a microglial subset previously described during the early stages of disease in several mouse models. Interestingly, the data indicate that microglia do not influence the behavior of ASO mice in the early stages of disease progression. However, microglia are the key mediators of the protective effects of prebiotic treatment in ASO mice. Overall, the conclusions of this paper are well supported by data, but some aspects should be considered to improve the manuscript.

      1) Colony-stimulating factor 1 receptor (CSF1R) inhibition has been widely used as a method for microglia depletion, however, the impact of this approach on peripheral immune cells is controversial. The authors elegantly showed that most gut-associated immune cell populations were unaffected by PLX5622. However, CSF1R signaling has been implicated in the maintenance of gut homeostasis. Could it be possible that PLX5622 treatment affects directly the gut microbiome composition? Are the beneficial changes in the gut microbiome composition of a prebiotic diet still maintained in combination with PLX5622? CSF1R inhibitors with low brain penetration such as PLX73086 and therefore unable to deplete resident microglia (Bellver- Landete, Victor et al., Nat Commun, 2019) would be helpful to rule out peripheral off-target effects.

      2) The authors claimed that microglial depletion eliminates the protective effects of the prebiotic diet in ASO mice by showing increased levels of aggregated aSyn in the SN (Fig 5G). However, microglial depletion also has the same effect on WT mice. How do authors interpret this result?

      3) What is the rationale for doing a long-term (17 weeks) prebiotic intervention? Have the authors considered doing a short-term intervention? The prebiotic diet should change quickly the gut microbiome composition within a few days or weeks.

    1. Reviewer #1 (Public Review):

      The software presented in this paper is well documented and represents a significant achievement that breaks new ground in terms of what is possible to render and explore in the web browser. This tool is essential for the exploration of SC2 data, but equally useful for the tree of life and other tree-like data sets.

    1. Reviewer #1 (Public Review):

      The paper by Gomez et al. describes investigations employing extracellular recordings of neural spiking in rat pups across different sleep states in primary (M1) and secondary (M2) cortices as well as in the prefrontal cortex (PFC) in response to spontaneous motor activity and tactile stimulation. The authors demonstrate activity across these areas that are associated with active sleep (AS) and identify responses in each region to internally generated movements and external stimuli. Because these results contradict earlier findings in the same areas under anesthesia, they also perform similar recordings in urethane anesthetized animals and show that similar responses are not observed under these conditions. Based on findings from anesthetized and unanesthetized recordings, the authors conclude that early responses associated with AS occur in higher cortical areas, a novel observation for the brain regions studied which had been missed in previous studies because they are absent under anesthesia. Finally, in their discussion, the authors consider the potential roles of state dependent activity in development and contend that differences in activity patterns between motor cortical areas and PFC reflect the diversity or heterogeneity of the inputs they respond to.

      The finding presented, particularly the observation of state specific activity in the PFC similar to that observed in more sensory linked areas of the motor cortex, are novel and of interest for their potential relevance to development. However, analysis of the recordings presented in the current manuscript are largely descriptive and do not convey much functional insight beyond simple observation of the phenomenon. In addition, some of the claims made, particularly those related to the differences between PFC and motor cortex, are not clearly supported by the data as currently presented. For these reasons, the study should be revised to including by incorporating additional analysis and potentially further experiments. In addition, clarification of the text and figures is needed to allow the findings to be clearly understood. Resolution of these issues would be important to improve the quality of the manuscript.

    1. Reviewer #1 (Public Review):

      Multiple myeloma (MM) is a common often incurable plasma cell disease. Fatty acid binding proteins (FABPs) represent biomarkers for aggressive disease in MM, and pharmacologically inhibiting FABPs kill tumor cells and induce cell cycle arrest. This work demonstrates that targeting FABP5 holds great therapeutic potential for killing diseased cells, with few negative off-target effects on healthy cells.

      The authors first found their FABP target by utilizing the Broad Institute's Cancer Dependency Map (DepMap), where only FABP5 exhibited a score in all 20 MM cell lines that demonstrated a strong reliance on FABP5 for survival. To test the effects of FABP5 in MM cell lines they created knock outs, however, the efficacy was relatively low with expression down only 84%. The results demonstrated a reduced proliferation and subsequently, the authors sought to use chemical FABP inhibitors. To understand how FABP5 inhibition could lead to reduced MM cell proliferation, RNAseq was performed. The results analysis demonstrated that MYC, a known oncogene, was found as a central downregulated node. MYC's importance was further confirmed with proteomic analysis.

      To help put these findings into clinical context, they investigated the combination of FABP inhibition (FABPi) with dexamethasone, a common therapy for MM patients, where they found that FABPi enhanced dexamethasone's efficacy. Overall, this is an outstanding manuscript that should help advance the overall understanding of MM. The major weakness relates to an unclear mechanism of action (MOA) for FABP5 in MM cells.

    1. Reviewer #1 (Public Review):

      Mutations in Doublecortin (DCX), which is a microtubule-binding protein cause lissencephaly. This manuscript by Rao et al. demonstrates the mechanism by which DCX affects retrograde transport in the neurons. Authors show that DCX functions to affect dynein transport in the axon via two different mechanisms - 1. By regulating dynein-microtubule interaction and 2. By regulating the interaction of JIP3 to the dynein motor complex. Interestingly, they have also shown the formation of the dynein-dynactin-JIP3 complex and reconstituted its motility in vitro. Authors demonstrate DCX regulation by affecting the recruitment of the second dynein in the dynein-dynactin-JIP3 complex to affect dynein velocity. Because DCX also regulates Kinesin-3 mediated transport, this work uncovers the role of DCX in regulating opposite polarity motors during neuronal growth. Overall the manuscript is well written, the work is original, experiments are performed carefully and most of the findings justify the conclusions drawn by the authors.

    1. Reviewer #1 (Public Review):

      In this manuscript by Kim et al., the authors use live-cell imaging of transcription in the Drosophila blastoderm to motivate quantitative models of gene regulation. Specifically, they focus on the role of repressors and use a 'thermodynamic' model as the conceptual framework for understanding the addition and placement of the repressor Runt, i.e. synthetic insertion of Runt repressor sites into the Bicoid-activated hunchback P2 enhancer. Coupled with kinetic modeling and live-cell imaging, this study is a sort of mathematical enhancer bashing experiment. The overarching theme is measuring the input/output relationship between an activator (bicoid), repressor (runt), and mRNA synthesis. Transcriptional repression is understudied in my opinion. One finding is that the inclusion of cooperativity between trans-acting factors is necessary for understanding transcriptional regulation. Most, if not all, of the tools used in this paper have been published elsewhere, but the real contribution is a deep, quantitative dissection of transcriptional regulation during development. As such, the only real questions for this referee are whether the modeling was done rigorously to produce some general biological conclusions. By and large, I think the answer is yes.

      Comments:

      Fig. 6 was the most striking figure for this referee, specifically that different placements of Runt molecules on the enhancer lead to distinct higher order interactions. I am wondering if the middle data column in Fig. 6 represents a real difference from the other two, and if so, it seems that the positioning - as opposed to simply the stoichiometry - is essential in cooperativity. This conclusion implies that transcriptional regulation is more precise than what some claim is just a mushy ball of factors close to a promoter. In other words, orientation may matter. Proximity may matter. Interactions in trans matter.

      There needs to be at least one prediction which is validated at the level of smFISH / mRNA in the embryo. Without detracting from the effort the authors have expended in looking directly at transcription, if the effects can't be felt by the blastoderm at the level of mRNA/cell, it become difficult to argue for the relevance to development. Also, I feel there is little chance that these measurements can be quantitatively replicated unless translated to the level of total protein or mRNA. Such a measurement (orthogonal quantitative confirmation of the repressor cooperativity result) would also assuage my concern about the time averaging as shown in Fig. S3.

    1. Reviewer #1 (Public Review):

      Generally, the strength of this work is the submolecular resolution provided by the MD simulations, while at the same time the weakness is that the results of such simulations are only as good as the force fields used to describe the interactions between gasdermin-D subunits within an assembly and between these subunits and the lipids in the membrane. These simulations yield several interesting results, while also raising various questions, as follows.

      The MD simulations are consistent with previous results (e.g., Ding et al., 2016 and Mulvihill et al., 2018, cited in manuscript that gasdermins preferentially bind to anionic lipids, which is not new, but the results are novel here in identifying these interactions at submolecular scale. However, by only showing results for interactions with PI(4,5)P2, without any results for other lipids (if only as a negative control), it remains hard for a reader to assess the relevance and strength of these interactions.

      The next result is that the 33-mer "prepore" gasdermin assembly deforms the membrane by just binding - and not inserting into - the membrane. It may seem surprising that such an effect of the membrane may occur without membrane insertion, but it is consistent with previous (experimental) observations for prepore assemblies of the cholesterol dependent cytolysins pneumolysin (Tilley et al., 2005; Faraj et al., Sci Rep 2020) and suilysin (Leung et al., 2014, cited in manuscript). The authors also present data on the 33-mer ring-shaped pore confirmation, not surprisingly finding this pore to be stable.

      The more novel results emerge when considering monomers and smaller oligomers. To assess their potential role in pore formation, MD simulations are shown that demonstrate stability of inserted monomers, dimers, etc. of gasdermin-D. Although, as noted by the authors, arc-shaped pores are a common feature for pore forming proteins, it is quite remarkable that a monomer is enough to provide a stable membrane-inserted configuration. The unanswered question, however, is if such smaller gasdermin assemblies will be able to insert into the membrane, presuming that there may be an activation barrier to overcome between prepore (membrane-bound) and pore (membrane-inserted) configuration. That is, while the MD results how that such small oligomers can adopt stable membrane-inserted configurations, they do not justify the authors' claim that such oligomers "create" membrane pores.

      The final main and valuable result is about the fate of the lipids in arc-shaped gasdermin assemblies, although the comparison with the ring-shaped pore is lacking (e.g., by initiating the pore assembly with lipids still embedded within the ring). For the arc-shaped pores, the lipids are shown to recede from the inside of the arcs, providing new insight into how the membrane is locally removed. Most intriguingly, the line tension of the lipids appear to "crack" the 16-mer assembly, resulting in a smaller-aperture slit-shaped pores (as have observed by AFM previously). One weakness here is that only a single such cracking event (N=1) is shown to result in the slit-shaped pore.

      Another question is how this observation relates to previous MD simulations (by the same lab, Vogele et al, 2019) of pneumolysin pores. Based on MD results and structural details, how do gasdermin-D and pneumolysin compare when viewed through the lens of MD?

      Finally, the authors conclude that there are two distinct pathways of membrane pore formation by gasdermin-D (Fig. 5), but do not explain why they exclude formation of larger arc-shaped "adhered prepores" as a pathway of pore formation. Why would larger adhered prepores only insert into the membrane as full rings and not as larger arc-shaped assemblies? That conclusion does not seem justified by the data.

    1. Reviewer #1 (Public Review):

      Xu et al show that mutants in three DNA replication proteins, Mcm2, Pole3, and Pole4 have defects in differentiation in a mouse embryonic stem cell (ESC) model. The Mcm2 mutant (called Mcm2-2A), which specifically blocks the interaction of Mcm2 with histones, has defects in multilineage differentiation and neural differentiation, despite having minimal effect on ESC proliferation or gene expression. Mcm2-2A fails to fully silence ESC genes and activate appropriate differentiation genes. Chromatin profiling analyses show Mcm2 binds many promoters. During differentiation, the Mcm2-2 mutant retains K3K27me3 at differentiation gene promoters and reduced accessibility, consistent with the observed defects in gene expression.

      The findings that Mcm2-2A has minimal effect on proliferation and gene expression in ESCs, but impairs differentiation are interesting, particularly since this mutant seems to separate the histone binding roles of Mcm2 and its roles in DNA replication. Furthermore, the fact the histone binding function is only necessary when cells exit the pluripotent state is of interest. The studies were reasonably thorough and generally support the conclusions that Mcm2 is important for reshaping histone modifications during differentiation, although the details by which this occurs are not clear. Although the authors used two different strategies for identifying the direct binding sites of Mcm2 on chromatin, Mcm2 enrichment at individual loci was relatively weak, suggesting Mcm2 may localize somewhat diffusely. This somewhat weakens the conclusions about the direct vs indirect effects of Mcm2 on chromatin structure and gene expression.

      Overall, this paper reports an interesting set of findings that have a few caveats/limitations regarding how Mcm2 mediates these effects on chromatin during ESC differentiation.

      My biggest question is about the Mcm2 CUT&RUN data, which appears to have low signal-to-noise. The authors appear to be aware of this issue, as they also used an Mcm2-FLAG line for CUT&RUN studies, with similarly low signal to noise. To be clear, this may be due to the binding properties of Mcm2, which may bind chromatin relatively broadly, causing few highly enriched peaks to be observed (similar to cohesin complex in the absence of CTCF). However, it makes the Mcm2 binding data difficult to interpret. First, most Mcm2 peaks seem to be near promoters. Promoters often have a small amount of signal in negative control (IgG or irrelevant antibody) CUT&RUN experiments, presumably due to their MNase accessibility. It is not clear to what extent Mcm2 peaks exceed background because no negative control CUT&RUN was performed. The high correlation of FLAG and Mcm2 CUT&RUN libraries might still be evident if some of this signal is due to background at TSSs. Second, the authors call 13,742 peaks, but browser tracks of some example peaks at the Pax6 and Nanog promoters show minimal enrichment relative to surrounding regions (Fig. 5I, 5S1B). I have concerns that some of these peaks called statistically significant are not biologically meaningful.

    1. Reviewer #1 (Public Review):

      The sea anemone Nematostella has been previously shown by the authors to exhibit diurnal patterns of movement around their culture dishes -- essentially they move around in darkness and not when in the light. This behaviour is entrained and continues to cycle when animals are kept in constant darkness. In this manuscript the authors test whether temperature cycles can substitute for light cycles in entraining this locomotory behaviour, and it turns out it can. They then test the effects of the two different entraining factors, light and temperature, when applied in phase (aligned exposure cycles) or out of phase (misaligned exposure cycles). The condition the authors call aligned (somewhat arbitrarily) is for the minimal temperature occurring at the beginning of the light cycle. They shift this alignment by 2, 4, 6, 8, 10 and 12 hours; so for example the first altered set has lights on 2 hours after the minimal temperature, and the second set four hours after the minimal temperature. Animals are conditioned to these new entraining cycles for 'at least 2 weeks', then tests applied. The tests are either the behaviour of the animals at a constant temperature in constant darkness, or gene expression under one example of these altered out-of-phase conditions.

      The authors view all data within a framework called 'sensory conflict' -- it is even the first two words of the title. This phrase is used in other papers to describe what seems to me an over-simplistic way to view the interactions between different entraining factors. Why is this 'conflict'? If they are two different environmental entraining signals and the cycle of one is shifted relative to the other you are simply changing the alignment of the cycles. By attempting to view the simple change in alignment within the formal framework of 'sensory conflict' the authors are limiting their (and the readers') ability to understand their results; all they see is different levels of conflict, which I would argue are not supported in any way by the results. If you were to shift the alignment of any two in-phase cycles so their peaks were then in anti-phase, you would wipe out any times in which neither of the two cycles was in the negative phase. It would not be 'sensory conflict' if in the anti-phase scenario no clear peak of the behaviour was evident. It would simply be the absence of peaks and troughs of conditions driving the behaviour. The framework used to discuss the data make it difficult to understand.

      After exploring impacts on shifting the alignment of light and temperature cycles the authors also examine changes in gene expression patterns in animals entrained to the new regimen. This is a powerful approach as changes in gene expression underlie most of the changes to cellular responses to the environment. The very detailed analysis finds complex changes in transcription patterns. A number of genes associated with biological clocks, or daily cycles of light, have previously been identified in other animals, and a small field has explored them in cnidarians including Nematostella and their relatives, the corals. These cycling genes are found in the results, but temperature was in general a stronger influencer on changes in gene expression. In terms of light, the PAR-bZIP genes once again show up as major responders, and this is strongly supported by the authors' examination of regulatory regions near differentially expressed genes, which are enriched in PAR-bZIP binding sites.

      Perhaps the most interesting set of genes identified are those that are only weakly rhythmic when the two entraining factor cycles are aligned, but become sharply rhythmic when they are in antiphase. The new sharp rhythms have an approximately 24 hour periodicity. As mentioned, temperature dominates changes in expression over light. Three core clock genes, Helt, PAR-bZIPa and Clock resist the shift to temperature and maintain their light driven cycles. The clear conclusion is that shifting the two entraining cycles results in large scale shifts in the underlying transcriptome for most rhythmic genes, with temperature dominating light except for core elements of the light responsive clock, and the major shifts are in metabolic processes.

      The authors provide a gene level examination of the cellular response to shifting the alignment of two different entraining factors that allows us to view, if not completely understand, how interactions between environmental signals are integrated.

    1. Reviewer #1 (Public Review):

      Here, Servello et al explore the role of temperature and the temperature-sensing neuron AFD in promoting protection against peroxide damage. Unlike many other environmental threats, peroxide toxicity is expected to be temperature-dependent, since its chemical reactivity should be enhanced by higher temperatures. The authors convincingly and rigorously show that transient exposure to 25C, a condition of mild heat stress in C. elegans, activates animals' defenses against peroxides but potentially not other agents. Interestingly, this response requires the temperature-sensing AFD neurons, though whether temperature-dependent AFD activity is itself involved in this regulation is not explored. Further, the authors find that temperature regulates AFD's expression of the insulin ins-39 and provide evidence supporting the idea that repression of ins-39 at 25C contributes to enhanced peroxide defense. The authors use transcriptomic approaches to explore gene expression changes in animals in which AFD neurons are ablated, providing evidence that the FoxO-family transcription factor DAF-16 potentiates AFD signaling. However, because AFD ablation triggers effects broader than transient 25C exposure, the significance of these findings for temperature-dependent peroxide defense is somewhat unclear. Additionally, the possibility that DAF-16 (as well as another protective factor, SKN-1) function in parallel to temperature stress is consistent with many of the results shown but is not as thoroughly considered. Together, these studies identify a fascinating example of pre-emptive threat response triggered by the detection of a potentiator of that threat, a phenomenon they term "enhancer sensing." While some predictions of the specificity of this phenomenon remain untested, the paper provides intriguing insight into the potential mechanisms by which it may occur.

      Major issues:

      The dependence of the enhancer-sensing phenomenon on AFD leads the authors to conclude that the 25C stimulus is sensed by AFD itself, but this needs to be directly tested. To do this, they could ask whether tax-4 function is required in AFD, or use mutants in which AFD's thermosensory function is compromised.

      The enhancer-sensing model is fascinating, but as it stands it is somewhat oversold. The authors could tone down the writing, indicating that this model is suggested rather than shown. Alternatively, they could more carefully test some of its predictions - for example by exploring the response to other threats (e.g. some of the toxicants described in Fig. S5) at 20C and 25C in WT and AFD-ablated animals.

      The role of ins-39 remains somewhat speculative. Fig 4F shows that ins-39 mutants have a reduced induction of peroxide defense, but it seems that this could be the result of a ceiling effect. The authors' model predicts that overexpression of ins-39, particularly at 25C, should sensitize animals to peroxide damage, a prediction that should be tested directly. Further, the authors seem to assume that AFD is the relevant site of ins-39 function, but this needs to be better supported.

      Most of the daf-16 and skn-1 experiments are carried out in AFD-ablated animals, making the relevance of these findings for the 25C-dependent induction of peroxide defense somewhat unclear. As the authors show, AFD ablation causes much more extensive changes than transient 25C exposure, clearly seen in slope of the line in 3C. Further, unlike 25C exposure, AFD ablation is a chronic and non-physiological state. It would be useful for the authors to be cautious in their interpretation of these findings and to be clearer about how strongly they can connect them to the "enhancer sensing" phenomenon. Along these lines, the potentiation idea could be toned down a bit. Much of the data is consistent with parallel function for daf-16 (and skn-1) - for example, Fig 5C indicates additive effects of daf-16 and 25C exposure; 6C shows that AFD ablation still has a clear effect on peroxide sensitivity in the absence of both daf-16 and skn-1; and Fig S8a shows that much of the transcriptional response to AFD ablation (along PC1) is intact in daf-16 animals.