... © 1999 by Company of Biologists 1999 vHNF1 Transcription factor Gene targeting Visceral endoderm Embryoid bodies HNF-4 During mammalian development, the blastocyst prepares for implantation within the receptive uterine epithelium by the generation of the first two cell lineages...

..., embryonic endoderm and mesoderm) from which the fetus is derived. An indication that the VE might have a critical role in this process emerged from studies of Hnf-4 − /− mouse embryos which fail to undergo normal gastrulation. Since expression of the transcription factor HNF-4 is restricted to the VE during...