ICM之組成
可區分為epiblast & primitive endoderm
epiblast日後形成胚胎
primitive endoderm日後形成胎盤
胚胎切片遠離ICM才可避免傷及epiblast
Dev Cell. 2019 Jul 22;50(2):139-154.e5. doi: 10.1016/j.devcel.2019.05.024. Epub 2019 Jun 13.
Epiblast Formation by TEAD-YAP-Dependent Expression of Pluripotency Factors and Competitive Elimination of Unspecified Cells.
Abstract
The epiblast is a pluripotent cell population first formed in preimplantation embryos, and its quality is important for proper development. Here, we examined the mechanisms of epiblast formation and found that the Hippo pathway transcription factor TEAD and its coactivator YAP regulate expression of pluripotency factors. After specification of the inner cell mass, YAP accumulates in the nuclei and activates TEAD. TEAD activity is required for strong expression of pluripotency factors and is variable in the forming epiblast. Cells showing low TEAD activity are eliminated from the epiblast through cell competition. Pluripotency factor expression and MYC control cell competition downstream of TEAD activity. Cell competition eliminates unspecified cells and is required for proper organization of the epiblast. These results suggest that induction of pluripotency factors by TEAD activity and elimination of unspecified cells via cell competition ensure the production of an epiblast with naive pluripotency.
Fig. 1. Organization of a preimplantation mouse embryo (late blastocyst).
The pluripotent epiblast cells produce body of embryo. The mechanism, by which all the epiblast cells aquire high quality, has been unknown.
The pluripotent epiblast cells produce body of embryo. The mechanism, by which all the epiblast cells aquire high quality, has been unknown.
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