Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA.
Adv Anat Embryol Cell Biol. 2024;238:23-46. doi: 10.1007/978-3-031-55163-5_2.
The regulation of mRNA transcription and translation is uncoupled during oogenesis. The reason for this uncoupling is two-fold. Chromatin is only accessible to the transcriptional machinery during the growth phase as it condenses prior to resumption of meiosis to ensure faithful segregation of chromosomes during meiotic maturation. Thus, transcription rates are high during this time period in order to produce all of the transcripts needed for meiosis, fertilization, and embryo cleavage until the newly formed embryonic genome becomes transcriptionally active. To ensure appropriate timing of key developmental milestones including chromatin condensation, resumption of meiosis, segregation of chromosomes, and polar body extrusion, the translation of protein from transcripts synthesized during oocyte growth must be temporally regulated. This is achieved by the regulation of mRNA interaction with RNA binding proteins and shortening and lengthening of the poly(A) tail. This chapter details the essential factors that regulate the dynamic changes in mRNA synthesis, storage, translation, and degradation during oocyte growth and maturation.
在卵子发生过程中，mRNA 的转录和翻译调控是解偶联的。这种解偶联有两个原因。在重新开始减数分裂之前，染色质会发生凝聚，以确保在减数成熟过程中染色体的正确分离，因此在这个阶段，染色质只对转录机制开放。在此期间，转录速率很高，以产生所有用于减数分裂、受精和胚胎分裂的转录本，直到新形成的胚胎基因组开始转录。为了确保关键发育里程碑的适时发生，包括染色质凝聚、减数分裂恢复、染色体分离和极体排出，必须对卵母细胞生长过程中合成的转录本的蛋白质翻译进行时间调节。这是通过调节 mRNA 与 RNA 结合蛋白的相互作用以及聚（A）尾的缩短和延长来实现的。本章详细介绍了在卵母细胞生长和成熟过程中调节 mRNA 合成、储存、翻译和降解的动态变化的基本因素。
