Anteroposterior patterning of the zebrafish ear through Fgf- and Hh-dependent regulation of hmx3a expression.

ABSTRACT: In the zebrafish, Fgf and Hh signalling assign anterior and posterior identity, respectively, to the poles of the developing ear. Mis-expression of fgf3 or inhibition of Hh signalling results in double-anterior ears, including ectopic expression of hmx3a. To understand how this double-anterior pattern is established, we characterised transcriptional responses in Fgf gain-of-signalling or Hh loss-of-signalling backgrounds. Mis-expression of fgf3 resulted in rapid expansion of anterior otic markers, refining over time to give the duplicated pattern. Response to Hh inhibition was very different: initial anteroposterior asymmetry was retained, with de novo duplicate expression domains appearing later. We show that Hmx3a is required for normal anterior otic patterning, and that otic patterning

SUBMITTER: Hartwell RD 

PROVIDER: S-EPMC6504108 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature