Feeding Underground: Consequences of Burrowing on the Design and Use of the Cranial System in Lizards

Using both mutant analyses with zebrafish mutants deficient in genes encoding members of this signaling pathway, as well as pharmacological treatment with cyclopamine, which inhibits Hh signaling, we have gained a better understanding of the role of this signaling pathway on branchial arch outgrowth. We conclude that while Hh is involved in cell proliferation within all pharyngeal cartilages, it plays a unique role in differentiation of branchial cartilages, since in the absence of Hh signaling these cartilages fail to develop.