eLife assessment
This manuscript suggests a novel mechanism of purifying selection by which programmed cell death contributes to the selective removal of mtDNA deletion mutations in C. elegans. The evidence for this mechanism of removal is strong although questions remain regarding the underlying mechanism and the role of canonical ageing pathways. Because of the likely central role of mtDNA deletions in ageing and age-dependent diseases, this work will be of interest to scientists in the field of mitochondrial biology as well as ageing.