On 2015 Apr 24, Robert Knight commented:

The morpholino used is designed to the start ATG and has been described previously by Cornell and Eisen (2002) and by Andermann, Ungos and Raible (2002). Titration of this morpholino was shown to lead to a loss of RB neurons and progressively trigeminal neurons, lateral line nerve and dorsal root ganglia. Crucially, this also caused a reduction or loss of neuroD expression and did not affect development of primary motor neurons, revealing a specific affect on sensory neurons. We validated our use of this morpholino by quantifying the effects on RB neuron development relative to morpholino dose and showed that despite a near total loss of RB neurons in an embryos, there was no affect on the number of neurons in the mesencephalic trigeminal nucleus (MTN) or in the nucleus of the tract of the posterior commissure (nTPC). We further showed that we could not detect ngn1 expression in either MTN or nTPC neurons, supporting the results of the morpholino knockdowns. We did not examine trigeminal ganglia neurons, therefore cannot comment on whether these were also affected by loss of ngn1 function as previously described.

On 2015 Apr 19, Sandra Rieger commented:

Knocking down ngn1 with a morpholino does not always lead to 100% knockdown of both trigeminal and RB neurons. It largely depends on the morpholino concentration and the type of morpholino used. Therefore, the statement that ngn1 is not required for trigeminal neuron development is not convincing, especially since crucial controls for the functionality of the morpholino injections are missing.

On 2015 Apr 19, Sandra Rieger commented:

Knocking down ngn1 with a morpholino does not always lead to 100% knockdown of both trigeminal and RB neurons. It largely depends on the morpholino concentration and the type of morpholino used. Therefore, the statement that ngn1 is not required for trigeminal neuron development is not convincing, especially since crucial controls for the functionality of the morpholino injections are missing.

On 2015 Apr 24, Robert Knight commented:

The morpholino used is designed to the start ATG and has been described previously by Cornell and Eisen (2002) and by Andermann, Ungos and Raible (2002). Titration of this morpholino was shown to lead to a loss of RB neurons and progressively trigeminal neurons, lateral line nerve and dorsal root ganglia. Crucially, this also caused a reduction or loss of neuroD expression and did not affect development of primary motor neurons, revealing a specific affect on sensory neurons. We validated our use of this morpholino by quantifying the effects on RB neuron development relative to morpholino dose and showed that despite a near total loss of RB neurons in an embryos, there was no affect on the number of neurons in the mesencephalic trigeminal nucleus (MTN) or in the nucleus of the tract of the posterior commissure (nTPC). We further showed that we could not detect ngn1 expression in either MTN or nTPC neurons, supporting the results of the morpholino knockdowns. We did not examine trigeminal ganglia neurons, therefore cannot comment on whether these were also affected by loss of ngn1 function as previously described.