Data for: Atoh1 is required for the formation of lateral line electroreceptors and hair cells, whereas Foxg1 represses an electrosensory fate

In electroreceptive jawed fishes and amphibians, individual lateral line
placodes form lines of neuromasts on the head containing mechanosensory
hair cells, flanked by fields of ampullary organs containing
electroreceptors - modified hair cells that respond to weak electric
fields. Extensively shared gene expression between neuromasts and
ampullary organs suggests that conserved molecular mechanisms are involved
in their development, but a few transcription factor genes are restricted
either to the developing electrosensory or mechanosensory lateral line.
Here, we used CRISPR/Cas9-mediated mutagenesis in G0-injected sterlet
embryos (Acipenser ruthenus, a sturgeon) to test the function of three
such genes. We found that the 'hair cell' transcription factor
gene Atoh1 is required for both hair cell and electroreceptor
differentiation in sterlet, and for Pou4f3 and Gfi1 expression in both
neuromasts and ampullary organs. These data support the conservation of
developmental mechanisms between hair cells and electroreceptors.
Targeting ampullary organ-restricted Neurod4 did not yield any phenotype,
potentially owing to redundancy with other Neurod genes that we found to
be expressed in sterlet ampullary organs. After targeting
mechanosensory-restricted Foxg1, ampullary organs formed within neuromast
lines, suggesting that Foxg1 normally represses their development, whether
directly or indirectly. We speculate that electrosensory organs may be the
'default' fate of lateral line primordia in electroreceptive
vertebrates.