Abstract:
Vertebrate oocytes face a particular challenge concerning the regulation of gene expression during meiotic maturation. Global transcription becomes quiescent in fully grown oocytes, remains halted throughout maturation and fertilization, and only resumes upon embryonic genome activation. Hence, the oocyte meiotic maturation process is largely regulated by protein synthesis from pre-existing maternal messenger RNAs (mRNAs) that are transcribed and stored during oocyte growth. Rapidly developing genome-wide techniques have greatly expanded our insights into the global translation changes and possible regulatory mechanisms during oocyte maturation. The storage, translation, and processing of maternal mRNAs are thought to be regulated by factors interacting with elements in the mRNA molecules. Additionally, posttranscriptional modifications of mRNAs, such as methylation and uridylation, have recently been demonstrated to play crucial roles in maternal mRNA destabilization. However, a comprehensive understanding of the machineries that regulate maternal mRNA fate during oocyte maturation is still lacking. In particular, how the transcripts of important cell cycle components are stabilized, recruited at the appropriate time for translation, and eliminated to modulate oocyte meiotic progression remains unclear. A better understanding of these mechanisms will provide invaluable insights for the preconditions of developmental competence acquisition, with important implications for the treatment of infertility. This review discusses how the storage, localization, translation, and processing of oocyte mRNAs are regulated, and how these contribute to oocyte maturation progression.
摘要:
脊椎动物卵母细胞在减数分裂成熟过程中面临着基因表达调控的特殊挑战。全局转录在完全生长的卵母细胞中变得静止,在整个成熟和受精过程中,只有在胚胎基因组激活后才能恢复。因此,卵母细胞减数分裂成熟过程在很大程度上由预先存在的母体信使RNA(mRNA)的蛋白质合成调节,这些mRNA在卵母细胞生长过程中被转录和储存。快速发展的全基因组技术极大地扩展了我们对卵母细胞成熟过程中全球翻译变化和可能的调节机制的见解。存储,翻译,母体mRNA的加工被认为是由与mRNA分子中的元件相互作用的因子调节的。此外,mRNA的转录后修饰,如甲基化和尿苷化,最近已被证明在母体mRNA不稳定中起关键作用。然而,对卵母细胞成熟过程中调节母体mRNA命运的机制仍然缺乏全面的了解。特别是,重要细胞周期成分的转录本是如何稳定的,在适当的时间招募翻译,和消除以调节卵母细胞减数分裂进展仍不清楚。对这些机制的更好理解将为获得发展能力的先决条件提供宝贵的见解,对不孕症的治疗具有重要意义。这篇评论讨论了如何存储,本地化,翻译,卵母细胞mRNA的加工受到调控,以及这些如何促进卵母细胞成熟进程。