In mammals, fertilization is followed by extensive reprogramming and reorganization of the chromatin accompanying the transcriptional activation of the embryo. This reprogramming results in blastomeres with the ability to give rise to all cell types and a complete organism, including extra‐embryonic tissues, and is known as totipotency. Transcriptional activation occurs in a process known as zygotic genome activation (ZGA) and is tightly linked to the expression of transposable elements, including endogenous retroviruses (ERVs) such as endogenous retrovirus with leucine tRNA primer (ERVL). Recent studies discovered the importance of ERVs in this process, yet the race to decipher the network surrounding these elements is still ongoing, and the molecular mechanism behind their involvement remains a mystery. Amid a recent surge of studies reporting the discovery of various factors and pathways involved in the regulation of ERVs, this review provides an overview of the knowns and unknowns in the field, with a particular emphasis on the chromatin landscape and how ERVs shape preimplantation development in mammals. In so doing, we highlight recent discoveries that have advanced our understanding of how these elements are involved in transforming the quiescent zygote into the most powerful cell type in mammals.

中文翻译：

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反转录转座子对早期胚胎合子基因组激活和染色质景观的影响


在哺乳动物中，受精之后是伴随着胚胎转录激活的染色质的广泛重编程和重组。这种重编程导致卵裂球能够产生所有细胞类型和完整的生物体，包括胚胎外组织，被称为全能性。转录激活发生在称为合子基因组激活 （ZGA） 的过程中，并且与转座因子的表达密切相关，包括内源性逆转录病毒 （ERV），例如具有亮氨酸 tRNA 引物 （ERVL） 的内源性逆转录病毒。最近的研究发现了 ERV 在此过程中的重要性，但破译围绕这些元素的网络的竞赛仍在进行中，它们参与背后的分子机制仍然是一个谜。在最近报告发现 ERV 调节涉及的各种因素和途径的研究激增中，本综述概述了该领域的已知和未知因素，特别强调染色质景观以及 ERV 如何塑造哺乳动物的植入前发育。在此过程中，我们重点介绍了最近的发现，这些发现促进了我们对这些元素如何参与将静止受精卵转化为哺乳动物中最强大的细胞类型的理解。