Mechanisms driving the transition from oocyte to embryo: The role of the mRNA decay activator ZFP36L2.

驱动卵母细胞向胚胎转变的机制：mRNA 衰变激活剂 ZFP36L2 的作用。

• 批准号: 10388655
• 负责人: Heidi Cook-Andersen
• 金额: $ 0.51万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-18 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10388655
• 关键词: Animals; Automobile Driving; Biological Models; Competence; DNA Methylation; Defect; Development; Down-Regulation; Elements; Embryo; Event; Failure; Female infertility; Fertilization; Gene Silencing; Genetic Models; Genetic Transcription; Goals; Histone H3; Mediating; Modeling; Modification; Oocytes; RNA-Binding Proteins; Role; Testing; Totipotent; Transcription Coactivator; Transcription Elongation; Transcription Initiation; ZFP36L2 gene; chromatin modification; genome-wide; histone methylation; insight; mRNA Decay; methylation testing; prevent; single-cell RNA sequencing

Project Summary Global transcriptional silencing is a highly conserved evolutionary event central to the transition from the fully differentiated oocyte to the totipotent embryo. Despite its importance in the development of all animals, this pivotal genome-wide event remains poorly understood. We have recently discovered that oocyte global transcriptional silencing depends on an mRNA decay activator. Oocyte-specific loss of ZFP36L2—an RNA- binding protein with a well-established role in AU-rich element-mediated mRNA decay—prevents oocytes from undergoing global transcriptional silencing. ZFP36L2-deficient oocytes are developmentally incompetent, with defects in maturation and fertilization leading to complete female infertility. Single cell RNA-seq analysis revealed that ZFP36L2 regulates scores of transcription regulators with central roles in chromatin modification and transcription initiation and elongation. This dysregulation resulted in failure to accumulate histone methylation marks associated with the silent, competent state. Our results define a critical role for an oocyte mRNA decay activator in the downregulation of transcription activators, leading to histone methylation, global transcriptional silencing and competence to transition from oocyte to embryo. These findings strongly point to a model in which global transcriptional silencing in the oocyte is mediated by mRNA decay. The goals of this proposal are to both uncover the mechanism(s) by which mRNA decay by ZFP36L2 brings about global transcriptional silencing in the oocyte and to take advantage of the insights provided by this unique genetic model system to investigate the role of ZFP36L2-dependent chromatin modifications critical for global transcriptional silencing and the successful transition from oocyte to embryo. To determine the role of mRNA decay in bringing about global transcriptional silencing, we will identify the direct targets of ZFP36L2 in the oocyte genome-wide and test the role of these factors in mediating global transcriptional silencing and oocyte developmental competence. We will determine the role of ZFP36L2 in chromatin modification, including histone H3 and DNA methylation, and test the role of these modifications in global transcriptional silencing in the oocyte. Finally, we will test whether ZFP36L2-dependent chromatin modifications established in the oocyte act to maintain global transcriptional silencing over the oocyte-to-embryo transition and/or set the stage for activation of new transcription in the newly formed embryo.

项目摘要 全球转录沉默是一个高度保守的进化事件，是从完全过渡的核心 将卵母细胞分化为全能胚胎。尽管它在所有动物的发展中都重要，但 关键的全基因组事件仍然知之甚少。我们最近发现卵母细胞全球 转录沉默取决于mRNA衰减激活剂。 ZFP36L2的卵母细胞特异性损失 - RNA- 结合蛋白在富含AU的元素介导的mRNA衰减中具有完善的作用 - 从 进行全球转录沉默。 ZFP36L2缺乏卵母细胞在开发中不称职，并且 成熟和受精的缺陷导致完全不育。单细胞RNA-seq分析 揭示ZFP36L2调节具有染色质修饰中心作用的数分转录调节剂 和转录启动和伸长。这种失调导致未积累组蛋白 甲基化标记与沉默，胜任状态相关。我们的结果定义了卵母细胞的关键作用 转录激活剂下调的mRNA衰变激活剂，导致组蛋白甲基化，全球 转录沉默和从卵母细胞过渡到胚胎的能力。这些发现强烈指出 mRNA衰变介导了卵母细胞中全局转录沉默的模型。目标的目标 提议既要揭示ZFP36L2的mRNA衰减的机制 卵母细胞中的转录沉默，并利用这种独特的遗传提供的见解 研究ZFP36L2依赖性染色质修饰的作用的模型系统对全局至关重要 转录沉默和从卵母细胞到胚胎的成功过渡。确定mRNA的作用 在实现全球转录沉默时，我们将确定ZFP36L2的直接目标 全卵母细胞基因组和测试这些因素在介导整体转录沉默和卵母细胞中的作用 发展能力。我们将确定ZFP36L2在染色质修饰中的作用，包括 Hisstone H3和DNA甲基化，并测试这些修饰在全球转录沉默中的作用 卵母细胞。最后，我们将测试是否在卵母细胞中建立ZFP36L2依赖性染色质修饰 采取行动以维持卵母细胞到embryo过渡的全球转录沉默和/或为 新形成的胚胎中新转录的激活。