Unique Regulation of RNA Pol II During Primordial Germ Cell Specification

原始生殖细胞规范过程中 RNA Pol II 的独特调控

• 批准号: 8828238
• 负责人: William G. KELLY
• 金额: $ 29.29万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-07 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8828238
• 关键词: Address; Affect; Animals; Appearance; Caenorhabditis elegans; Cell Cycle; Cell Cycle Arrest; Cell Death; Cell Survival; Cells; ChIP-seq; Characteristics; Chromatin; Chromatin Modeling; Chromatin Structure; Complex; Defect; Dependency; Development; Developmental Process; Embryo; Embryonic Development; Ensure; Epigenetic Process; Epitopes; Event; Exhibits; Fertility; Gametogenesis; Gatekeeping; Gene Expression; Gene Expression Profile; Generations; Genetic; Genetic Transcription; Genome; Genomics; Germ; Germ Cells; Germ Lines; Goals; Health; Human; Individual; Investigation; Lead; Maintenance; Mammals; Mission; Molecular; Molecular Genetics; Mus; Necrosis; Nematoda; Output; Pattern; Phase; Phosphotransferases; Pluripotent Stem Cells; Polymerase; Positive Transcriptional Elongation Factor B; Process; Public Health; RNA; RNA Polymerase II; Rana; Regulation; Reporting; Repression; Research; Small RNA; Somatic Cell; Staging; Sterility; Structure of primordial sex cell; Study models; Tissues; Transcript; Transcriptional Regulation; Untranslated RNA; base; disability; embryonic stem cell; epigenetic regulation; epigenome; fly; genome-wide; histone methyltransferase; histone modification; human disease; insight; mutant; neuronal cell body; novel; offspring; pluripotency; programs; zygote

DESCRIPTION (provided by applicant): The germ lineage is the guardian of the genome and gatekeeper of the genetic, and epigenetic, information that is passed between generations. An essential characteristic of germ cells is their underlying totipotency: the inherent capacity to generate all tissues. Totipotency is an epigenetic characteristic-- processes that affect the epigenetic content of the germ line genome not only have the potential to affect germ line and somatic development within an individual, but can also affect developmental processes in subsequent generations. Our long-term goal is to understand the epigenetic processes that operate during the germ cell cycle within and between generations: i.e., how is heritable epigenetic content is established, how is it recognized and interpreted, and how is it reprogrammed as the germ line progresses through each stage? My lab has been at the forefront of establishing the nematode C. elegans as an exceptional model for studying these processes, as it possesses numerous genetic and molecular strengths that make both intra- and trans-generational studies of the germ line cycle feasible. Furthermore, the process of germ cell specification in C. elegans is remarkably similar to specification in mammals. These include a mixed soma/germline/embryonic stem cell (ESC)-like phase, a prolonged G2-stage cell cycle arrest, genome-wide epigenetic reprogramming, and transient specialized regulation of RNA Pol II. Indeed, observations made in C. elegans have stimulated the investigations in mammals that have cemented these similarities. One of these similarities is the focus of the proposed research: the unique regulation of RNA Pol II during primordial germ cell (PGC) specification. In many animals, including worms, flies, frogs, and mice, there is a period of RNA Pol II inactivity that accompanies PGC specification. In all species this is observed as the absence of the "elongating RNA Pol II phospho-epitope", Ser2P. We have recently shown that in C. elegans, there is a curious appearance of Ser2P at PGC specification that is transient and regulated by kinases in a manner distinct from the surrounding somatic cells. Such regulation may contribute to, or be a special characteristic of, germ line totipotency as reports suggest Ser2P shows unique regulation in pluripotent stem cells. We are poised to identify the mechanisms that regulate Pol II during PGC specification, identify its genomic distribution in the nascent PGCs, and identify the transcriptome that may contribute to the functions of early and post-embryonic germ cell development. This will yield important insights into conserved aspects of germ cell development, and provide further paradigms for similar investigations in mammals. Given the absolute importance of the germ line for both trans-generational genome protection and epigenetic modes of inheritance, these studies are highly significant as they will inform how these processes proceed normally, and why when disrupted they lead to human congenital and fertility defects.

描述（由申请人提供）：生殖谱系是基因组的监护人，也是遗传和表观遗传信息的守门人，这些信息在两代人之间传递。生殖细胞的一个基本特征是其潜在的全能性：产生所有组织的固有能力。全能性是一种表观遗传特征-影响生殖系基因组表观遗传内容的过程不仅有可能影响个体内的生殖系和体细胞发育，而且还可能影响后代的发育过程。我们的长期目标是了解在生殖细胞周期内和两代之间运作的表观遗传过程：即，可遗传的表观遗传内容是如何建立的，它是如何被识别和解释的，以及它是如何随着生殖系在每个阶段的进展而被重新编程的？ 我的实验室一直处于建立线虫C.线虫是研究这些过程的特殊模型，因为它具有许多遗传和分子优势，使生殖系周期的代内和跨代研究都是可行的。此外，还对C.秀丽线虫与哺乳动物的特徴非常相似。这些包括混合的索马/生殖系/胚胎干细胞（ESC）样期、延长的G2期细胞周期停滞、全基因组表观遗传重编程和RNA Pol II的瞬时特化调节。事实上，在C。秀丽线虫刺激了对哺乳动物的研究，巩固了这些相似性。其中一个相似之处是拟议研究的重点：原始生殖细胞（PGC）特化过程中RNA Pol II的独特调控。 在许多动物中，包括蠕虫、苍蝇、青蛙和小鼠，存在伴随PGC特化的RNA Pol II不活动期。在所有物种中，这被观察为不存在“延长RNA Pol II磷酸表位”Ser 2 P。我们最近已经证明，在C。在线虫中，PGC特化中存在Ser 2 P的奇怪外观，其是瞬时的并且以不同于周围体细胞的方式由激酶调节。这种调节可能有助于生殖系全能性，或者是生殖系全能性的特殊特征，因为报告表明Ser 2 P在多能干细胞中显示出独特的调节。我们准备确定PGC规范过程中调节Pol II的机制，确定其在新生PGC中的基因组分布，并确定可能有助于早期和胚胎后生殖细胞发育功能的转录组。这将对生殖细胞发育的保守方面产生重要的见解，并为哺乳动物的类似研究提供进一步的范例。鉴于生殖系对于跨代基因组保护和表观遗传模式的绝对重要性，这些研究非常重要，因为它们将告知这些过程如何正常进行，以及为什么当它们被破坏时会导致人类先天性和生育缺陷。