The anterior visceral endoderm of the mouse embryo is established from both preimplantation precursor cells and by de novo gene expression after implantation.

ABSTRACT: Initiation of the development of the anterior-posterior axis in the mouse embryo has been thought to take place only when the anterior visceral endoderm (AVE) emerges and starts its asymmetric migration. However, expression of Lefty1, a marker of the AVE, was recently found to initiate before embryo implantation. This finding has raised two important questions: are the cells that show such early, preimplantation expression of this AVE marker the real precursors of the AVE and, if so, how does this contribute to the establishment of the AVE? Here, we address both of these questions. First, we show that the expression of another AVE marker, Cer1, also commences before implantation and its expression becomes consolidated in the subset of ICM cells that comprise the primitive endoderm. Second,

SUBMITTER: Torres-Padilla ME 

PROVIDER: S-EPMC3353121 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature