Distinct sequential cell behaviours direct primitive endoderm formation in the mouse blastocyst
Citations Over TimeTop 10% of 2008 papers
Abstract
The first two lineages to differentiate from a pluripotent cell population during mammalian development are the extraembryonic trophectoderm (TE) and the primitive endoderm (PrE). Whereas the mechanisms of TE specification have been extensively studied, segregation of PrE and the pluripotent epiblast (EPI) has received comparatively little attention. A current model of PrE specification suggests PrE precursors exhibit an apparently random distribution within the inner cell mass of the early blastocyst and then segregate to their final position lining the cavity by the late blastocyst. We have identified platelet-derived growth factor receptor alpha (Pdgfralpha) as an early-expressed protein that is also a marker of the later PrE lineage. By combining live imaging of embryos expressing a histone H2B-GFP fusion protein reporter under the control of Pdgfra regulatory elements with the analysis of lineage-specific markers, we investigated the events leading to PrE and EPI lineage segregation in the mouse, and correlated our findings using an embryo staging system based on total cell number. Before blastocyst formation, lineage-specific factors are expressed in an overlapping manner. Subsequently, a gradual progression towards a mutually exclusive expression of PrE- and EPI-specific markers occurs. Finally, cell sorting is achieved by a variety of cell behaviours and by selective apoptosis.
Related Papers
- → The Endoderm of the Mouse Embryo Arises by Dynamic Widespread Intercalation of Embryonic and Extraembryonic Lineages(2008)408 cited
- → Dynamic morphogenetic events characterize the mouse visceral endoderm(2003)126 cited
- → Methods for Derivation of Human Embryonic Stem Cells(2005)84 cited
- → Induction by the endoderm in birds(1933)97 cited
- → Live imaging reveals that the endoderm of the mouse embryo is generated by intercalation of extraembryonic and epiblast-derived cells(2008)