Oral-aboral axis specification in the sea urchin embryo, IV: hypoxia radializes embryos by preventing the initial spatialization of nodal activity.

ABSTRACT: The oral-aboral axis of the sea urchin embryo is specified conditionally via a regulated feedback circuit involving the signaling gene nodal and its antagonist lefty. In normal development nodal activity becomes localized to the prospective oral side of the blastula stage embryo, a process that requires lefty. In embryos of Strongylocentrotus purpuratus, a redox gradient established by asymmetrically distributed mitochondria provides an initial spatial input that positions the localized domain of nodal expression. This expression is perturbed by hypoxia, leading to development of radialized embryos lacking an oral-aboral axis. Here we show that this radialization is not caused by a failure to express nodal, but rather by a failure to localize nodal activity to one side of the embryo. This

SUBMITTER: Coffman JA 

PROVIDER: S-EPMC3929957 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature