Repression of mesodermal fate by foxa, a key endoderm regulator of the sea urchin embryo.

摘要: The foxa gene is an integral component of the endoderm specification subcircuit endomesoderm regulatory network in Strongylocentrotus purpuratus embryo. Its transcripts become confined to veg2, then veg1 endodermal territories, and, following gastrulation, throughout gut. It also expressed stomodeal ectoderm. gatae and otx genes provide input into pregastrular system foxa, Foxa represses its own transcription, resulting oscillatory temporal expression profile. Here, we report three separate essential functions gene: it mesodermal fate veg2 endomesoderm; required postgastrular development for gut-specific genes; necessary stomodaeum formation. If reduced by a morpholino, more cells pigment other mesenchymal cell types, less gut specified, larva has no mouth. Experiments which blastomere transplantation combined with MASO treatment demonstrate that, normal endoderm, crucial role repress gcm response Notch signal, hence fate. Chimeric recombination experiments or ectoderm contained show region controls each functions. These that distinct embryonic networks.