The temporal and spatial segregation of the two extra-embryonic cell lineages, trophectoderm and primitive endoderm (TE and PE respectively), from the pluripotent epiblast (EPI) during mammalian pre-implantation development are prerequisites for the successful implantation of the blastocyst. The mechanisms underlying these earliest stages of development remain a fertile topic for research and informed debate. In recent years novel roles for various transcription factors, polarity factors and signalling cascades have been uncovered. This mini-review seeks to summarise some of this work and to put it into the context of the regulative nature of early mammalian development and to highlight how the increasing evidence of naturally occurring asymmetries and heterogeneity in the embryo can bias specification of the distinct cell types of the blastocyst.

中文翻译：

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早期哺乳动物胚胎的发育控制：影响细胞命运的异质细胞之间的竞争。

在哺乳动物植入前发育过程中，从多能外胚层 (EPI) 中分离出两种胚外细胞谱系，滋养外胚层和原始内胚层（分别为 TE 和 PE）是成功植入胚泡的先决条件。这些最早发展阶段背后的机制仍然是研究和知情辩论的沃土。近年来，人们发现了各种转录因子、极性因子和信号级联的新作用。这篇小型评论旨在总结其中的一些工作，并将其置于早期哺乳动物发育的调节性质的背景下，并强调胚胎中自然发生的不对称和异质性的证据越来越多，如何影响不同细胞类型的规范的囊胚。