胚胎母源-合子转换期中的表观遗传调控

哺乳动物个体由终端分化的单倍体精子和卵子受精融合成的双倍体受精卵发育而来。在胚胎发育的初始阶段,合子基因组处于休眠状态,胚胎发育调控由卵母细胞内母源调控逐渐转换为合子基因组调控(Maternal-Zygotic Transition,MZT)。在此期间,随着母源物质的清除,合子基因组激活(Zygotic Genome Activation,ZGA),但调控MZT的具体分子机制还不清楚。最新研究表明,DNA甲基化、染色质重塑、组蛋白表观修饰、ncRNA在MZT和ZGA中发挥重要的作用。本文总结了上述4种表观修饰在动物植入前胚胎MZT中的生物学功能和特异的分子机制,对揭示动物胚胎MZT的调控机理有借鉴意义。

Epigenetic Regulation of Maternal-To-Zygotic Transition

Mammalian individuals develop from diploid fertilized eggs, which are formed by terminally differentiated haploid sperm and egg fertilization. In the initial stage of embryonic development, the zygote genome is dormant, and the regulation of embryonic development is gradually transformed from maternal regulation in oocytes to zygotic transition(MZT). During this period, the zygote genome activation(ZGA) is activated with the clearance of maternal material, but the specific molecular mechanism regulating MZT is still unclear. Recent studies have shown that DNA methylation, chromatin remodeling, histone epigenetic modification and ncRNA play important roles in MZT and ZGA. This paper summarizes the biological functions and specific molecular mechanisms of the above four apparent modifications in MZT of preimplantation embryos, which can be used for reference to reveal the regulatory mechanism of MZT of animal embryos.