Sexual dimorphism of piRNA transcription and target silencing mechanisms in C. elegans

线虫 piRNA 转录的性别二态性和靶标沉默机制

• 批准号: 10673887
• 负责人: John Kim
• 金额: $ 47.71万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10673887
• 关键词: Animals; Automobile Driving; Binding; Binding Sites; Biogenesis; Biological; Caenorhabditis elegans; Complex; Computational algorithm; Data; Development; Elements; Ensure; Equilibrium; Exhibits; Family; Female; Fertility; Gene Targeting; Genes; Genetic Transcription; Genome; Genomics; Goals; Human; Infertility; Maintenance; Organism; Pathway interactions; Phenotype; Process; Publishing; RNA; Regulation; Regulator Genes; Regulatory Element; Repression; Research; Role; Small Nuclear RNA; Small RNA; Specificity; Spermatogenesis; Spliceosomes; System; Testing; Therapeutic; Variant; cofactor; fly; genome integrity; insight; male; male health; molecular scale; mutant; novel; paralogous gene; piRNA; preservation; promoter; recruit; reproductive; sex; sexual dimorphism; transcription factor; transcriptomics; transposon/insertion element

Abstract The Piwi-interacting RNA (piRNA) pathway promotes animal fertility by protecting the germline genome against mobile DNA elements. Despite this well-established paradigm, several critical gaps remain in our understanding of piRNA mechanisms, including the sexual dimorphism of their biogenesis and downstream gene regulatory functions. We discovered that the ancient SNAPc (or SNPC) transcription complex that transcribes small nuclear RNAs (snRNAs) of the spliceosome has diversified in C. elegans to drive the expression of male- and female- specific piRNAs, in addition to its canonical function in snRNA transcription. In the fly and human, the SNPC holocomplex is composed of SNPC-1, SNPC-3, and SNPC-4 subunits, each encoded by a single gene. In contrast, C. elegans expresses several paralogs of SNPC-1 and SNPC-3 that we propose dictate the specificity of three distinct SNPC complexes. In particular, based on our published and preliminary data, we hypothesize that the SNPC-1 paralogs comprise the primary specificity factors that define the unique functions of each SNPC complex for either snRNA or sex-specific piRNA transcription. In this proposal, we will first investigate how this specificity is achieved by identifying the cis-regulatory elements recognized by each SNPC transcription complex (Aim 1). We will also determine the specificity domains, cofactors, and subcellular assembly of the piRNA and snRNA SNPC complexes (Aim 2). Finally, we will characterize the biological phenotypes of the male and female piRNA mutants and leverage these insights to predict and validate endogenous gene targets of sex-specific piRNAs. Collectively, this research will bridge the gaps in our understanding of sexual dimorphism in piRNA transcription and gene targeting mechanisms that ensure proper germline development and robust reproductive capacity of animals. 1

抽象的 Piwi 相互作用 RNA (piRNA) 途径通过保护种系基因组免受 移动DNA元件。尽管有这个完善的范式，但我们的理解中仍然存在一些关键差距 piRNA 机制的研究，包括其生物发生和下游基因调控的性别二态性 功能。我们发现古老的 SNAPc（或 SNPC）转录复合物可以转录小核 秀丽隐杆线虫中剪接体的 RNA (snRNA) 已多样化，可驱动雄性和雌性的表达 除了其在 snRNA 转录中的典型功能外，还具有特定的 piRNA。在果蝇和人类中，SNPC 全复合体由 SNPC-1、SNPC-3 和 SNPC-4 亚基组成，每个亚基由单个基因编码。在 相比之下，线虫表达 SNPC-1 和 SNPC-3 的几个旁系同源物，我们认为这些同源物决定了特异性 三个不同的 SNPC 复合体。特别是，根据我们发布的初步数据，我们假设 SNPC-1 旁系同源物包含定义每个 SNPC 独特功能的主要特异性因素 snRNA 或性别特异性 piRNA 转录复合物。在本提案中，我们将首先研究如何 通过识别每个 SNPC 转录复合物识别的顺式调控元件来实现特异性 （目标 1）。我们还将确定 piRNA 的特异性结构域、辅因子和亚细胞组装 snRNA SNPC 复合物（目标 2）。最后，我们将描述雄性和雌性的生物学表型 piRNA 突变体并利用这些见解来预测和验证性别特异性的内源基因靶标 piRNA。总的来说，这项研究将弥补我们对 piRNA 性别二态性理解的空白 转录和基因靶向机制可确保适当的种系发育和强大的生殖能力 动物的能力。 1