Functions of MOV10L1 in piRNA biogenesis and germ cell development

描述(申请人提供)：本申请的长期目标是阐明一类新的小型非编码RNA的生物发生和功能，即piRNAs。RNA干扰已经成为基因沉默的一种主要调控机制，在这种机制中，小的非编码RNA起着序列特异性引导的作用。MicroRNAs是一类特征相对较好的非编码小RNA，对正常发育至关重要，并与许多人类疾病有关。相比之下，piRNAs(Piwi相互作用RNAs)的生物发生和功能却知之甚少。piRNAs是一类不同的生殖系特异性非编码小RNA。最近在包括苍蝇、斑马鱼和小鼠在内的各种生物中的研究表明，Piwi蛋白和piRNAs是沉默生殖系中的转座元件所必需的。我们发现，MOV10L1是一种可能的RNA解旋酶，与所有Piwi蛋白结合，是piRNA途径的重要组成部分。因此，MOV10L1是唯一已知的哺乳动物piRNA途径的主要调节因子。MOV10L1基因的破坏会导致雄性的piRNAs丢失和减数分裂停滞。利用我们独特的MOV10L1条件突变体和其他遗传模型，我们计划：1)研究MOV10L1/piRNA缺失圆形精子细胞的染色质完整性和功能；2)阐明MOV10L1在粗线期piRNAs生物发生和功能中的作用；3)生化表征MOV10L1同源物在家蚕(Bombyx Mori)BmN4卵巢细胞系piRNA生物发生中的作用。这些研究将阐明piRNA生物发生的机制基础，以及MOV10L1和粗线期piRNA在精子发生过程中维持基因组完整性的新功能。这些研究将为人类疾病的病因、诊断和预防提供洞察力，包括男性不育和出生缺陷。 与公共卫生相关：piRNAs是一类新的非编码小RNA。了解它们在维持生殖系基因组完整性方面的功能，将为人类疾病的病因、诊断和预防提供洞察力，如男性不育、妊娠丢失和出生缺陷。

DESCRIPTION (provided by applicant): The long-term objective of the current application is to elucidate the biogenesis and function of a novel class of small non-coding RNAs, the piRNAs. RNA interference has emerged as a major regulatory mechanism in gene silencing in which small non-coding RNAs function as sequence-specific guides. MicroRNAs, a relatively well- characterized class of small non-coding RNAs, are essential for normal development and are implicated in many human diseases. In contrast, the biogenesis and function of piRNAs (Piwi-interacting RNAs), a diverse class of germline-specific small non-coding RNAs, is poorly understood. Recent studies in diverse organisms including fly, zebra fish, and mice have shown that Piwi proteins and piRNAs are required for silencing of transposable elements in the germline. We have found that MOV10L1, a putative RNA helicase, binds to all Piwi proteins and is an essential component of the piRNA pathway. Therefore, MOV10L1 is the only known master regulator of the mammalian piRNA pathway. Disruption of Mov10l1 leads to a loss of piRNAs and meiotic arrest in males. Using our unique Mov10l1 conditional mutant and other genetic models, we plan to: 1) investigate the chromatin integrity and functional competency of MOV10L1/piRNA-deficient round spermatids, 2) elucidate the role of MOV10L1 in the biogenesis and function of pachytene piRNAs, and 3) biochemically characterize the role of the MOV10L1 homologue in piRNA biogenesis in cultured silkworm (Bombyx mori) BmN4 ovarian cell lines. These studies will elucidate the mechanistic basis of piRNA biogenesis and a novel function for MOV10L1 and pachytene piRNAs in maintaining genome integrity during spermiogenesis. These studies will provide insight into etiology, diagnosis, and prevention of human diseases including male infertility and birth defects. PUBLIC HEALTH RELEVANCE: piRNAs are a novel class of small non-coding RNAs. Understanding their function in maintaining genome integrity in the germline will provide insight into the etiology, diagnosis, and prevention of human diseases such as male infertility, pregnancy loss, and birth defects.