<i>Sox11</i> genes affect neuronal differentiation in the developing zebrafish enteric nervous system

The vertebrate enteric nervous system (ENS) is derived from vagal neural crest cells, which enter the foregut as progenitors that migrate from rostral to caudal to populate the entire length of the gut. Here, we show that transcription factors <i>sox11a</i> and <i>sox11b</i>, zebrafish orthologs of the human <i>SOX11</i> gene, are highly expressed in neural crest cells transitioning from progenitors to differentiating neuronal subtypes. Accordingly, CRISPR-Cas9 depletion shows that loss of <i>sox11</i> paralogs reduces the number of neurons that express the inhibitory motor neuron marker <i>adcyap1b</i> without affecting cell proliferation or death. Transcription factor footprinting analysis of open chromatin regions identified by ATAC-seq reveals Sox11 binding sites in the <i>adcyap1b</i> enhancer. Furthermore, mutational analysis shows these binding sites are required for mediating enhancer-driven reporter expression. Taken together, our results demonstrate an important and previously unrecognized role for <i>sox11a</i> and <i>sox11b</i> in neuronal subtype specification in the developing zebrafish ENS.