Laboratory of Integrative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
University of Chinese Academy of Sciences, Beijing, China.
Nature. 2022 May;605(7909):315-324. doi: 10.1038/s41586-022-04625-0. Epub 2022 Mar 21.
After fertilization, the quiescent zygote experiences a burst of genome activation that initiates a short-lived totipotent state. Understanding the process of totipotency in human cells would have broad applications. However, in contrast to in mice, demonstration of the time of zygotic genome activation or the eight-cell (8C) stage in in vitro cultured human cells has not yet been reported, and the study of embryos is limited by ethical and practical considerations. Here we describe a transgene-free, rapid and controllable method for producing 8C-like cells (8CLCs) from human pluripotent stem cells. Single-cell analysis identified key molecular events and gene networks associated with this conversion. Loss-of-function experiments identified fundamental roles for DPPA3, a master regulator of DNA methylation in oocytes, and TPRX1, a eutherian totipotent cell homeobox (ETCHbox) family transcription factor that is absent in mice. DPPA3 induces DNA demethylation throughout the 8CLC conversion process, whereas TPRX1 is a key executor of 8CLC gene networks. We further demonstrate that 8CLCs can produce embryonic and extraembryonic lineages in vitro or in vivo in the form of blastoids and complex teratomas. Our approach provides a resource to uncover the molecular process of early human embryogenesis.
受精后，静息的受精卵经历了基因组激活的爆发，从而启动了短暂的全能状态。了解人类细胞中的全能性过程将具有广泛的应用。然而，与在小鼠中不同，尚未报道在体外培养的人类细胞中观察到合子基因组激活或 8 细胞（8C）阶段的时间，并且对胚胎的研究受到伦理和实际考虑的限制。在这里，我们描述了一种无转基因、快速可控的方法，可从人类多能干细胞中产生 8C 样细胞（8CLC）。单细胞分析确定了与这种转化相关的关键分子事件和基因网络。功能丧失实验鉴定了 DPPA3 的基本作用，DPPA3 是卵母细胞中 DNA 甲基化的主要调节剂，以及 TPRX1，一种在小鼠中缺失的真兽类全能细胞同源盒（ETCHbox）家族转录因子。DPPA3 在整个 8CLC 转化过程中诱导 DNA 去甲基化，而 TPRX1 是 8CLC 基因网络的关键执行者。我们进一步证明，8CLCs 可以在体外或体内以胚状体和复杂畸胎瘤的形式产生胚胎和胚胎外谱系。我们的方法提供了一种资源，可以揭示早期人类胚胎发生的分子过程。
