Active cell movements coupled to positional induction are involved in lineage segregation in the mouse blastocyst.

ABSTRACT: In the mouse blastocyst, some cells of the inner cell mass (ICM) develop into primitive endoderm (PE) at the surface, while deeper cells form the epiblast. It remained unclear whether the position of cells determines their fate, such that gene expression is adjusted to cell position, or if cells are pre-specified at random positions and then sort. We have tracked and characterised dynamics of all ICM cells from the early to late blastocyst stage. Time-lapse microscopy in H2B-EGFP embryos shows that a large proportion of ICM cells change position between the surface and deeper compartments. Most of this cell movement depends on actin and is associated with cell protrusions. We also find that while most cells are precursors for only one lineage, some give rise to both, indicating that lineag

SUBMITTER: Meilhac SM 

PROVIDER: S-EPMC3353123 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature