Negative autoregulation of Oct3/4 through Cdx1 promotes the onset of gastrulation.

Gastrulation marks the onset of germ layer formation from undifferentiated precursor cells maintained by a network including the Pou5f1 gene, Oct3/4. Negative regulation of the undifferentiated state is a prerequisite for germ layer formation and subsequent development. A novel cross-regulatory network was characterized including the Pou5f1 and Cdx1 genes as part of the signals controlling the onset of gastrulation.