Danio rerio Raw sequence reads. Danio rerio

Distinct shaping of the upper versus lower facial skeleton is essential for function of the vertebrate jaw and middle ear, yet the cellular mechanisms by which this occurs have remained unclear. Here, we show that Endothelin1 (Edn1) signaling accelerates mesenchymal condensation and subsequent cartilage formation in the lower face through antagonism of Jagged-Notch signaling and Prrx1 transcription factors. A genomic analysis of facial skeletal precursors in mutants and overexpression embryos reveals that Jagged-Notch signaling represses genes that are strongly induced as pharyngeal arch neural crest-derived cells begin skeletal differentiation.