RNA-mediated Chromatin Regulation and Epigenetic Inheritance in C. elegans

线虫中 RNA 介导的染色质调控和表观遗传

• 批准号: 10133085
• 负责人: Guoping Gu
• 金额: $ 34.54万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10133085
• 关键词: Aging; Animal Model; Animals; Auxins; Biochemical; Biochemical Genetics; Biology; C. elegans genome; Caenorhabditis elegans; Cell Nucleus; Cells; Cellular biology; Chromatin; Clustered Regularly Interspaced Short Palindromic Repeats; Complement; Cytoplasm; DNA; DNA Transposable Elements; Defect; Development; Disease; Double-Stranded RNA; Environment; Enzymes; Epigenetic Process; Event; Funding; Gene Silencing; Generations; Genes; Genetic; Genetic Transcription; Genetic study; Genome; Genomics; Germ Cells; Guide RNA; Heritability; Heterochromatin; Histone Code; Human Development; Kinetics; Link; Maintenance; Mediating; Meiosis; Memory; Methyltransferase; Modernization; Molecular; Nature; Nuclear; Nuclear RNA; Pathway interactions; Phase; Play; Process; Production; Proteins; Psychological reinforcement; Publishing; RNA; RNA Interference; RNA Processing; RNA Splicing; Regulation; Regulatory Element; Retrotransposon; Role; Signal Transduction; Small Interfering RNA; Small RNA; System; Testing; Transcript; Untranslated RNA; Work; chromatin modification; deep sequencing; epigenetic memory; epigenetic silencing; feeding; gene repression; genomic locus; histone methyltransferase; histone modification; human disease; insight; mature animal; mutant; novel; novel strategies; promoter; single molecule; tool; transgenerational epigenetic inheritance; whole genome

PROJECT SUMMARY: Nuclear RNAi is an evolutionarily conserved pathway in which small interfering RNAs (siRNAs) guide chromatin modifications and transcriptional repression. It protects the host genome by epigenetically silencing transposons and other “non-self” DNA. Since its discovery, nuclear RNAi has provided a powerful paradigm to study RNA-mediated chromatin regulation and transgenerational epigenetic inheritance. In C. elegans, nuclear RNAi and heritable silencing can be conveniently triggered by feeding worms with exogenous dsRNA targeting a native gene. This approach is complemented by investigating molecular events occurring at the endogenous targets in the C. elegans genome. Using this uniquely tractable system, our published works done in the past funding cycle have made the following discoveries, which also raised new questions: (1) The heterochromatin mark H3K9me3 can be functionally decoupled from transcriptional silencing during the maintenance phase. What is the H3K9me3-independent transcriptional repression mechanism? (2) The heterochromatin enzyme SET-32 is required for the establishment phase but dispensable for the maintenance phase of RNAi. How does SET-32 promote silencing establishment? (3) Endogenous targets are transiently expressed in a subset of germ cells at the proliferation and early meiotic stage in wild type adult animals. What is the mechanism of the developmental regulation of the low level transcription, and how does it contribute to the reinforcement of epigenetic silencing memory? (4) When we de-silence endogenous targets of nuclear RNAi, their transcripts are enriched in germline nuclei. What is the significance of this nuclear localization in triggering RNAi? In the proposed new funding cycle, we will take both novel and established genetic, biochemical, cell biology, and computational approaches to answer these questions by achieving the following aims. (1) Investigate the transgenerational epigenetic mechanisms of silencing establishment. (2) Characterize a novel histone modification, H3K23me3, and its role in germline nuclear RNAi. (3) Determine the triggering mechanisms at the endogenous target of nuclear RNAi. The proposed studies, which explore fundamental yet unmapped territory of modern biology, will advance our understanding of RNA-chromatin interaction, inheritance of epigenetic states, and genome surveillance, which are all relevant to human development and disease.

项目概要： 核 RNAi 是一种进化上保守的途径，其中小干扰 RNA (siRNA) 引导 染色质修饰和转录抑制。它通过表观遗传沉默来保护宿主基因组 转座子和其他“非自身”DNA。自发现以来，核 RNAi 提供了一个强大的范例 研究RNA介导的染色质调控和跨代表观遗传。在秀丽隐杆线虫中，核 通过给蠕虫喂食外源 dsRNA 靶向，可以方便地触发 RNAi 和遗传性沉默 天然基因。通过研究内源性发生的分子事件来补充该方法 秀丽隐杆线虫基因组中的目标。使用这个独特的易于处理的系统，我们过去发表的作品 资助周期取得了以下发现，这也提出了新的问题：（1）异染色质 mark H3K9me3 可以在维持阶段从功能上与转录沉默解耦。 H3K9me3 独立的转录抑制机制是什么？ (2)异染色质酶 SET-32在RNAi的建立阶段是必需的，但在RNAi的维持阶段是可有可无的。怎么样 SET-32促进消音建立？ (3) 内源性靶标在一个子集中瞬时表达 野生型成年动物中处于增殖和早期减数分裂阶段的生殖细胞。其作用机制是什么 低水平转录的发育调控，以及它如何有助于强化 表观遗传沉默记忆？ (4) 当我们去沉默核 RNAi 的内源性靶标时，它们的转录本 富含种系核。这种核定位对于触发 RNAi 有何意义？在 拟议的新资助周期，我们将采用新颖的和已建立的遗传、生物化学、细胞生物学和 通过实现以下目标来回答这些问题的计算方法。 (1) 调查 沉默建立的跨代表观遗传机制。 (2) 表征新的组蛋白 修饰、H3K23me3 及其在种系核 RNAi 中的作用。 (3) 确定触发机制 核RNAi的内源性靶标。拟议的研究探索了基本但尚未映射的 现代生物学的领域，将增进我们对 RNA-染色质相互作用、遗传的理解 表观遗传状态和基因组监测都与人类发育和疾病相关。