小鼠中来源于mRNA的piRNA的生成机理研究

项目名称： 小鼠中来源于mRNA的piRNA的生成机理研究

项目编号： No.31271379

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 韩春生

作者单位： 中国科学院动物研究所

项目金额： 80万元

中文摘要： piRNAs是近年来发现的一类在生殖细胞中特异且大量表达的小RNAs。目前该领域的研究表明，来源于重复序列的piRNAs可能在生成的同时也降解了逆转座子的RNAs，从而其生成和功能紧密相关。而其他类型piRNAs的生成机制和功能还不清楚。我们在前期研究中检测了小鼠精子发生过程三个重要阶段（精原细胞、精母细胞、圆形精子细胞）小RNAs的表达谱，利用生物信息学方法对piRNAs进行了系统分析。发现生殖细胞中约有三分之一的mRNAs能剪切产生piRNAs（这类mRNAs被命名为PRMRs）。PRMRs在物种间很保守，富含反义转录本，并且含有更多剪接变体。在本申请中，我们计划用体外培养的精原干细胞（SSCs）来研究PRMRs加工生成piRNAs的可能机制，研究反义转录本和RNA剪接在该过程中的作用，鉴定piRNA前体中与piRNAs生成有关的特征序列和结合蛋白。

中文关键词： 生殖细胞；精子发生；非编码RNA；piRNA；基因组

英文摘要： piRNAs are a novel class of small RNAs that were specifically produced from germ cells in large quantities. piRNAs that map to repetitive sequences were generated from retrotransposon RNAs, therefore their production is tightly coupled to its function. However, the mechanism for the production of other types of piRNAs and their functions are largely unknown. In our previous studies, we profiled the expression of small RNAs at three important stages of mouse spermatogenesis (spermatogonia, spermatocytes, and round spermatids) and performed in-depth bioinformatics analysis of the sequences of piRNA and their precursors. We found that about one-third of mRNAs were potential precursors of piRNAs, and named such mRNAs as PRMRs. Sequences of PRMRs were more conserved evolutionarily, possessed more splice isoforms and more antisense transcripts compared with non-PRMRs. In the present application, we are planning to investigate how piRNAs are processed from PRMRs. We will examine how antisense transcripts and alternative splicing are related to piRNA generation. We will also examine whether there is any sequence motif(s) and novel protein factors that may play a role in the production of piRNAs. These results will contribute to people's understanding of the production and function of small RNAs.

英文关键词： germ cell；spermatogenesis；noncoding RNA；piRNA；genome