Evolution of axis specification mechanisms in jawed vertebrates: insights from a chondrichthyan.

ABSTRACT: The genetic mechanisms that control the establishment of early polarities and their link with embryonic axis specification and patterning seem to substantially diverge across vertebrates. In amphibians and teleosts, the establishment of an early dorso-ventral polarity determines both the site of axis formation and its rostro-caudal orientation. In contrast, amniotes retain a considerable plasticity for their site of axis formation until blastula stages and rely on signals secreted by extraembryonic tissues, which have no clear equivalents in the former, for the establishment of their rostro-caudal pattern. The rationale for these differences remains unknown. Through detailed expression analyses of key development genes in a chondrichthyan, the dogfish Scyliorhinus canicula, we have reconst

SUBMITTER: Coolen M 

PROVIDER: S-EPMC1847705 | biostudies-literature | 2007 Apr

REPOSITORIES: biostudies-literature