What defines the maternal transcriptome?
What defines the maternal transcriptome?
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DOI：
10.1042/bst20201125
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发表时间：
2021-11-01
影响因子：
3.9
通讯作者：
Vincent SD
中科院分区：
文献类型：
--
作者：
Tora L;Vincent SD
在体细胞中，RNA 聚合酶 II (Pol II) 转录起始是由通用转录因子 TFIID（包含 TATA 结合蛋白 (TBP) 和 13 个 TBP 相关因子 (TAF)）与核心启动子的结合开始的。然而，在生长的卵母细胞中，活性 Pol II 转录不依赖于 TFIID/TBP，因为在卵母细胞生长过程中，TBP 被其脊椎动物特异性旁系同源物 TBPL2 取代。 TBPL2 不与 TAF 相互作用，但与 TFIIA 稳定结合。母体转录组是在生长的卵母细胞的细胞质中产生和储存的 mRNA 群体。受精后，母体 mRNA 由受精卵从卵母细胞遗传。随着卵母细胞生长后转录变得沉默，这些 mRNA 成为活性蛋白质翻译的唯一来源。它们将参与完成卵母细胞终末分化、受精和早期发育启动所需的蛋白质库，直到胚胎中转录的重新激活，称为合子基因组激活（ZGA）。所有这些事件都是由母体转录组的重要重塑控制的。该过程结合了存储转录本的细胞质再腺苷化（允许其翻译）以及通过脱腺苷化与脱帽结合进行的不同 mRNA 降解波，以消除编码不再需要的蛋白质的转录本。 ZGA 后，重塑结束，母体转录本几乎全部被清除。过去，小鼠母体转录组很少受到关注，但最近的进展为小鼠母体 mRNA 动态调节带来了新的见解。本综述将讨论过去和最近与小鼠母体转录组动态相关的机制的数据。
In somatic cells, RNA polymerase II (Pol II) transcription initiation starts by the binding of the general transcription factor TFIID, containing the TATA-binding protein (TBP) and 13 TBP-associated factors (TAFs), to core promoters. However, in growing oocytes active Pol II transcription is TFIID/TBP-independent, as during oocyte growth TBP is replaced by its vertebrate-specific paralog TBPL2. TBPL2 does not interact with TAFs, but stably associates with TFIIA. The maternal transcriptome is the population of mRNAs produced and stored in the cytoplasm of growing oocytes. After fertilization, maternal mRNAs are inherited by the zygote from the oocyte. As transcription becomes silent after oocyte growth, these mRNAs are the sole source for active protein translation. They will participate to complete the protein pool required for oocyte terminal differentiation, fertilization and initiation of early development, until reactivation of transcription in the embryo, called zygotic genome activation (ZGA). All these events are controlled by an important reshaping of the maternal transcriptome. This procedure combines cytoplasmic readenylation of stored transcripts, allowing their translation, and different waves of mRNA degradation by deadenylation coupled to decapping, to eliminate transcripts coding for proteins that are no longer required. The reshaping ends after ZGA with an almost total clearance of the maternal transcripts. In the past, the murine maternal transcriptome has received little attention but recent progresses have brought new insights into the regulation of maternal mRNA dynamics in the mouse. This review will address past and recent data on the mechanisms associated with maternal transcriptome dynamic in the mouse.