Define piRNA biogenesis and function in mice

定义小鼠中 piRNA 的生物发生和功能

基本信息

批准号：
10222720
负责人：
Xin Li
金额：
$ 38.5万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2023-07-31
项目状态：
已结题

项目摘要

Reproduction is a fundamental feature of life. Animals usually require the differentiation of germ cells to create gametes. The gametogenesis process is delicately regulated, defects in which lead to fertility problems that impact 15% of humans. PIWI-interacting RNAs (piRNAs) are the most recently discovered and rapidly evolving class of small RNAs in animals. In vertebrates, piRNAs are almost exclusively expressed in testis, and they are essential for spermatogenesis. Some piRNAs guide PIWI proteins to silence transposable elements through sequence complementarity; humans, mice, and rooster, however, also produce a distinct and abundant set of non-repetitive piRNA sequences whose targets are unknown. My long-term goal is to understand the biology of piRNAs and their functions in male fertility. There is no obvious conservation of piRNA species, and piRNAs are heterogeneous: an organism carries millions of different piRNA sequences. The diversity is a result of their unusual biogenesis. Long single-stranded piRNA precursors are cleaved into thousands of snippets, and these fragments are loaded into PIWI proteins and become piRNAs. This fragmentation, which is poorly understood, distinguishes piRNA processing from other RNA fates. My previous work defined the precise transcription units of piRNA producing loci in mice, paving the way for the analysis of their post-transcriptional processing and their functions. I have further developed new methodologies and animal models to overcome longstanding roadblocks in piRNA research. In unpublished work, we found that ribosomes appear to participate in piRNA biogenesis, and that piRNAs act to regulate sperm epigenomes including RNAs and histones. Here, I propose to focus on two questions: 1) What principles designate a sequence to become a piRNA? 2) What is the function of piRNAs beyond transposable element silencing in male reproduction? The findings from this work may lead to the discovery of new mechanisms in male fertility and RNA biology.

繁殖是生命的基本特征。动物通常需要生殖细胞的分化来产生配子。配子发生过程受到微妙的调节，缺陷会导致生育问题影响15%的人类。 PIWI 相互作用 RNA (piRNA) 是最近发现且快速发展的动物体内的一类小RNA。在脊椎动物中，piRNA 几乎只在睾丸中表达，并且它们对于精子发生至关重要。一些 piRNA 引导 PIWI 蛋白通过以下方式沉默转座元件：序列互补性；然而，人类、小鼠和公鸡也产生了一组独特且丰富的靶标未知的非重复 piRNA 序列。我的长期目标是了解生物学 piRNA 及其在男性生育力中的功能。 piRNA 物种没有明显的保守性，并且 piRNA 是异质的：一个生物体携带数百万个不同的 piRNA 序列。多样性是他们的结果不寻常的生物发生。长单链 piRNA 前体被切割成数千个片段，这些片段片段被加载到 PIWI 蛋白中并成为 piRNA。人们对这种碎片化知之甚少， piRNA 加工与其他 RNA 命运的区别。我之前的工作定义了精确的转录单位小鼠体内 piRNA 产生位点的研究，为分析其转录后加工和分析铺平了道路他们的职能。我进一步开发了新的方法和动物模型来克服长期存在的问题 piRNA 研究的障碍。在未发表的工作中，我们发现核糖体似乎参与了 piRNA 生物发生，并且 piRNA 可以调节精子表观基因组，包括 RNA 和组蛋白。在此，我建议重点关注两个问题：1）指定序列成为 piRNA 的原则是什么？ 2）什么是 piRNA 在雄性生殖中除转座元件沉默之外的功能？这项工作的结果可能会导致男性生育力和RNA生物学新机制的发现。