摘要
Dear Editor,Cell-fate decisions are governed by comprehensive generegulatory programs.During the preimplantation development,at least two waves of cell fate decisions are made while the cells gradually lose their totipotency(Schrode et al.,2013).The first decision involves the spatial separation of outer-residing trophectoderm(TE)cells from inner cell mass(ICM)in E3.5 mouse blastocyst.The second decision involves gene expression refinements and active cell sorting within the ICM that ultimately results in epiblast(EPI)cells,residing deep within the ICM,and the primitive endoderm(PrE)cells comprising a monolayer of blastocoel-facing cells at the surface of the ICM(Schrode et al.,2013).OCT4,SOX2,and NANOG are master transcription factors(TFs)essential for the formation and maintenance of the pluripotent ICM cells and their in vitro counterparts mouse embryonic stem cells(ESCs).On the other hand,GATA4,GATA6,and SOX17 are master TFs of the PrE cells and their in vitro counterparts extraembryonic endoderm stem cells(XENs).
基金
We thank Dr.Philippe Soriano for providing the XENB1 cell line.Research in Wang laboratory was funded by grants from the NIH(R01GM129157,R01HD095938,and R01HD097268)and NYSTEM(C32583GG and C32569GG).
