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: 10512577
• 负责人: John Kim
• 金额: $ 47.01万
• 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/10512577
• 关键词: Address; Animals; Automobile Driving; Binding; Binding Sites; Biogenesis; Biological; Caenorhabditis elegans; Complex; Computational algorithm; Data; Development; Elements; Ensure; Equilibrium; Exhibits; Family; Female; Fertility; Foundations; Gene Targeting; Genes; Genetic Transcription; Genome; Genomics; Goals; Human; Infertility; Maintenance; Organism; Pathway interactions; Phenotype; Process; Publishing; RNA; Regulation; Regulator Genes; Regulatory Element; Research; Role; Small Nuclear RNA; Small RNA; Specificity; Spermatogenesis; Spliceosomes; System; Testing; Therapeutic; Variant; base; cofactor; fly; genome integrity; insight; male; male health; molecular scale; mutant; novel; paralogous gene; 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元素。尽管有一个公认的范式，但我们的理解仍然存在一些关键差距 PIRNA机制的生物发生和下游基因调节的性二态性 功能。我们发现抄录小核的古代SNAPC（或SNPC）转录复合物 剪接体的RNA（SNRNA）在秀丽隐杆线虫中多元化，以驱动雄性和女性的表达 除了其在SnRNA转录中的规范功能外，特定的PIRNA。在苍蝇和人类中，SNPC 全磁复合体由SNPC-1，SNPC-3和SNPC-4亚基组成，每个亚基由一个基因编码。在 对比，秀丽隐杆线虫表达了我们提出的几个SNPC-1和SNPC-3的旁系同源物决定了特异性 在三个不同的SNPC复合物中。特别是，根据我们已发布和初步数据，我们假设 SNPC-1旁系同源物包含定义每个SNPC唯一功能的主要特异性因子 用于SNRNA或性别特异性的PIRNA转录的复合物。在此提案中，我们将首先调查如何 特异性是通过识别每个SNPC转录复合物识别的顺式调节元件来实现的 （目标1）。我们还将确定piRNA的特异性域，辅助因子和亚细胞组件 SnRNA SNPC复合物（AIM 2）。最后，我们将表征男性和女性的生物学表型 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 pirnas。总的来说，这项研究将弥合我们对Pirna性二态性的理解的差距 转录和基因靶向机制，以确保适当的种系发育和鲁棒性生殖 动物的能力。 1