Control and coordination of the maternal-to-zygotic transition

母体向合子转变的控制和协调

基本信息

批准号：
9233196
负责人：
Jan M Skotheim
金额：
$ 32.07万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2021-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9233196
关键词：
ATAC-seq Address Adult Affect Alpha Cell Amphibia Biological Assay Cell Count Cell Cycle Cell Cycle Checkpoint Cell division Cell-Free System Cells ChIP-seq Chromatin Chromatin Structure Complex Coupled Cytoplasm DNA DNA biosynthesis DNA replication fork Data Development Embryo Event Fertilization Fishes Gene Expression Gene Expression Regulation Genetic Transcription Genome Genomic DNA Growth Histone H3 Histones Human In Vitro Kinetics Label Link Location Measurement Measures Messenger RNA Metabolic Methods Modeling Molecular Chaperones Nuclear Nucleosomes Organism Phase Phenotype RNA RNA Polymerase II Rana Role System Testing Titrations Transcription Initiation Transcriptional Activation Transcriptional Regulation Work Xenopus base blastocyst cell growth cell motility cell type density egg experimental study fly genome-wide in vivo inhibitor/antagonist insight public health relevance temporal measurement transcriptome sequencing vertebrate embryos zygote

项目摘要

DESCRIPTION (provided by applicant): The development of an adult multi-cellular organism from a single fertilized egg requires the proliferation and differentiation of a large number of cells. In many species, the early post-fertilization divisions occur rapidly and synchronously without growth phases and cell cycle checkpoints. These early embryos are almost entirely transcriptionally inactive and therefore driven by maternally supplied RNAs. At the Mid-Blastula Transition (MBT), the embryo initiates large-scale transcription from the zygotic genome and cells gain growth phases and checkpoints. Previous work suggested that the MBT is initiated by the increased DNA-to-cytoplasmic ratio resulting from repeated rounds of DNA replication and cell division without cell growth. This led to the hypothesis that the progressive titration of an inhibitory factor present in the embryo allows the initiation of zygotic transcription. Using a cel free system that recapitulates zygotic genome activation in vitro, we purified the transcriptional inhibitory activity present in the Xenopus egg cytoplasm and identified histones H3/H4 as DNA-titrated inhibitors of the MBT. Manipulating histone levels quantitatively shifts the onset of zygotic transcription and cell cycle lengthening in vivo, demonstrating a specific role for chromatin state in MBT initiation. This raises the question as to how histone titration and chromatin state are mechanistically linked to transcription and cell cycle duration. To address this, we will measure zygotic transcription and nucleosome occupancy genome wide at unprecedented temporal resolution through early development in control and histone manipulated embryos. We will determine mechanism linking DNA replication and histone levels. Successful completion of these aims will identify the mechanism through which global histone levels can be used to coordinate transcription and cell division with development. Since activating zygotic transcription is the first major transition after fertilization in human embryos our work determining how chromatin based mechanisms regulate the initiation of transcription will also provide insight global gene regulation and developmental reprogramming in the early vertebrate embryo.

描述（通过应用提供）：从单个受精卵中发展成人多细胞组织的发展需要大量细胞的增殖和分化。在许多物种中，早期有施用师在没有生长阶段和细胞周期检查点的迅速和同步发生。这些早期的胚胎几乎完全是转录的非活性，因此由主要提供的RNA驱动。在中间芽跃迁（MBT）上，该胚胎从合子基因组开始大规模转录，细胞获得生长阶段和检查点。先前的工作表明，MBT是由DNA复制复制和细胞分裂的反复回合而没有细胞生长而引起的DNA与环质比的增加。这导致了以下假设：胚胎中存在的抑制因子的进行性滴定允许二氏转录的启动。使用在体外概括二吻合基因组激活的CEL系统，我们纯化了Xenopus卵细胞质中存在的转录抑制活性，并将组蛋白H3/H4鉴定为MBT的DNA-硝化抑制剂。操纵组蛋白水平数量地改变了体内的二元转录和细胞周期延长的发作，这表明了染色质状态在MBT倡议中的特定作用。这就提出了一个问题，即组蛋白滴定和染色质状态如何机械地与转录和细胞周期持续时间联系起来。为了解决这个问题，我们将通过对控制和组蛋白操纵的胚胎的早期发育来衡量在前所未有的临时分辨率下，在前所未有的临时分辨率下衡量二合一转录和核病患者基因组。我们将确定连接DNA复制和组蛋白水平的机制。这些目标的成功完成将确定可以使用全球组蛋白水平与开发协调转录和细胞分裂的机制。由于激活二合作转录是人类胚胎受精后的第一个主要转变，因此我们决定基于染色质的机制如何调节转录的倡议还将在早期脊椎动物胚胎中提供洞察力的全球基因调节和发育重编程。