Unlike pluripotent cells, which generate only embryonic tissues, totipotent cells can generate a full organism, including extra-embryonic tissues. A rare population of cells resembling 2-cell-stage embryos arises in pluripotent embryonic stem (ES) cell cultures. These 2-cell-like cells display molecular features of totipotency and broader developmental plasticity. However, their specific nature and the process through which they arise remain outstanding questions. Here we identified intermediate cellular states and molecular determinants during the emergence of 2-cell-like cells. By deploying a quantitative single-cell expression approach, we identified an intermediate population characterized by expression of the transcription factor ZSCAN4 as a precursor of 2-cell-like cells. By using a small interfering RNA (siRNA) screen, we identified epigenetic regulators of 2-cell-like cell emergence, including the non-canonical PRC1 complex PRC1.6 and the EP400-TIP60 complex. Our data shed light on the mechanisms that underlie exit from the ES cell state toward the formation of early-embryonic-like cells in culture and identify key epigenetic pathways that promote this transition.

中文翻译：

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培养中早期胚胎样细胞出现的分子路线图。

与仅产生胚胎组织的多能细胞不同，全能细胞可以产生完整的有机体，包括胚胎外组织。多能胚胎干 (ES) 细胞培养物中出现了类似于 2 细胞阶段胚胎的稀有细胞群。这些 2 细胞样细胞显示出全能性和更广泛的发育可塑性的分子特征。然而，它们的具体性质和它们产生的过程仍然是悬而未决的问题。在这里，我们确定了 2 细胞样细胞出现期间的中间细胞状态和分子决定因素。通过部署定量单细胞表达方法，我们确定了一个中间群体，其特征在于转录因子 ZSCAN4 表达为 2 细胞样细胞的前体。通过使用小干扰 RNA (siRNA) 筛选，我们确定了 2 细胞样细胞出现的表观遗传调节因子，包括非经典 PRC1 复合物 PRC1.6 和 EP400-TIP60 复合物。我们的数据揭示了从 ES 细胞状态退出以在培养中形成早期胚胎样细胞的机制，并确定了促进这种转变的关键表观遗传途径。