Functions of MOV10L1 in piRNA biogenesis and germ cell development

描述（由申请人提供）：当前申请的长期目标是阐明一类新型小非编码rna pirna的生物发生和功能。RNA干扰已成为基因沉默的主要调控机制，其中小的非编码RNA作为序列特异性向导发挥作用。MicroRNAs是一类特征相对较好的小非编码rna，对正常发育至关重要，并与许多人类疾病有关。相比之下，pirna （piwi相互作用rna）的生物发生和功能，一种不同种类的种系特异性小非编码rna，知之甚少。最近对包括苍蝇、斑马鱼和小鼠在内的多种生物的研究表明，Piwi蛋白和pirna是种系转座因子沉默所必需的。我们发现MOV10L1，一种假定的RNA解旋酶，结合所有Piwi蛋白，是piRNA通路的重要组成部分。因此，MOV10L1是唯一已知的哺乳动物piRNA通路的主调控因子。在男性中，Mov10l1的破坏导致pirna的丢失和减数分裂停止。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缺陷圆形精子的染色质完整性和功能能力；2)阐明Mov10l1在粗线素piRNA的生物发生和功能中的作用；3)在培养家蚕（Bombyx mori） BmN4卵巢细胞系中，研究Mov10l1同源物在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。这些研究将为男性不育和出生缺陷等人类疾病的病因、诊断和预防提供见解。

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.