早期胚胎发育合子基因组激活调控

Regulation of Zygotic Genome Activation in Early Embryonic Development

动物早期胚胎发育始于分化成熟的雌雄配子经受精后重编程为全能性合子。在胚胎发育的初期,合子基因组的转录水平处于静默状态,母源物质调控占据主导地位。随着胚胎发育的进行,母源物质会经历分阶段的降解,合子基因组开始逐渐激活转录,标志着早期胚胎发育从母源性调控向合子基因组调控的转变,也称为母源-合子转换(maternal-zygotic transition,MZT)。其中一个关键的转折性事件就是合子基因组激活(zygotic genome activation,ZGA),ZGA的正确发生对于早期胚胎发育和细胞命运决定至关重要。然而,目前对于ZGA的调控因子和具体的分子机制仍知之甚少。研究表明,ZGA在不同物种中存在较大差异,可能受到DNA甲基化、组蛋白修饰、非编码RNA、染色质重塑以及ZGA相关因子等多种调控因素的影响。本文探讨了上述几种调控因素影响合子基因组激活的研究进展,对进一步研究早期胚胎ZGA的相关机制具有借鉴意义。

The development of animal early embryos commences with the reprogramming of terminally differentiated gametes into totipotent zygotes following fertilization.During the initial stages of embryonic development,the transcriptional levels of zygotic genome remain silent and maternal gene products dominate the regulation of development.As embryonic development progresses,the maternal gene products undergo phased degradation while the zygotic genome gradually activates transcription,marking the transition from the maternal regulation to the zygotic genome regulation in early embryonic development,which is also referred to as the maternal-zygotic transition(MZT).Zygotic genome activation(ZGA)is a critical turning process in this transition,and its accurate occurrence is crucial for early embryonic development and cell fate decisions.However,the regulatory factors and molecular mechanisms of ZGA remain poorly understood.Studies have shown that ZGA varies greatly among different species and may be affected by a variety of regulatory factors such as DNA methylation,histone modification,non-coding RNA,chromatin remodeling and ZGA related factors.Here,we review the research progress of the above regulatory factors affecting ZGA,which can provide valuable insights for further investigations into the ZGA related mechanisms of early embryos.