Upon fertilization, terminally differentiated gametes are transformed to a totipotent zygote, which gives rise to an embryo. How parental epigenetic memories are inherited and reprogrammed to accommodate parental-to-zygotic transition remains a fundamental question in developmental biology, epigenetics, and stem cell biology. With the rapid advancement of ultra-sensitive or single-cell epigenome analysis methods, unusual principles of epigenetic reprogramming begin to be unveiled. Emerging data reveal that in many species, the parental epigenome undergoes dramatic reprogramming followed by subsequent re-establishment of the embryo epigenome, leading to epigenetic “rebooting.” Here, we discuss recent progress in understanding epigenetic reprogramming and their functions during mammalian early development. We also highlight the conserved and species-specific principles underlying diverse regulation of the epigenome in early embryos during evolution.

受精后，终末分化的配子转化为全能受精卵，从而产生胚胎。父母的表观遗传记忆如何被遗传和重新编程以适应父母到合子的转变仍然是发育生物学、表观遗传学和干细胞生物学中的一个基本问题。随着超灵敏或单细胞表观基因组分析方法的快速发展，表观遗传重编程的不寻常原理开始被揭开。新数据显示，在许多物种中，亲代表观基因组经历了戏剧性的重编程，随后胚胎表观基因组重新建立，导致表观遗传“重新启动”。在这里，我们讨论了在哺乳动物早期发育过程中理解表观遗传重编程及其功能的最新进展。