Alonso, Luis Enrique i Fernández Rodríguez, Carlos Jesús (2013). Los discursos del presente. Un análisis de los imaginarios sociales contemporáneos

Abstract

The maternal determinant VegT is required for both endoderm, andmesoderm formation by the Xenopus embryo. An important downstreammediator of VegT action is Xsox17, which has been proposed to be inducedin cell-autonomous, then signal-dependent phases. We show that Xsox17 isa direct VegT target, but that direct induction of Xsox17 by VegT israpidly inhibited. This inhibition is relieved by TGF- beta signalling,to which the future endoderm cell is sensitised by VegT, resulting inthe observed dependence on cell contact for maintained Xsox17expression. We propose that this change in regulation is a consequenceof a VegT-induced repressor, inhibiting direct induction of earlyendoderm markers by VegT, and contributing to the formation of theboundary of the endodermal domain. (C) 2003 Elsevier Science (USA). Allrights reserved.