..., loss of RA signaling does not affect foxi1 expression or otic competence, but instead results in delayed onset of fgf3 expression and impaired otic induction. fgf8 mutants depleted of RA signaling produce few otic cells, and these cells fail to form a vesicle, indicating that Fgf8 is the primary factor...

..., is necessary and sufficient for otic induction. However, an alternative model proposes that Fgf must cooperate with Wnt8 to induce otic differentiation. Using a genetic approach in zebrafish, we tested the roles of Fgf3, Fgf8 and Wnt8. We demonstrate that localized misexpression of either Fgf3 or Fgf8...

... Pax2 Inner ear Otic induction Chick The first morphologically discernible structures of inner ear development in the chick embryo are the otic placodes, which arise as two ectodermal thickenings lateral to the prospective rhombomeres 5 and 6 at the 3- to 5-somite stage. The placodes...