VASA is an evolutionarily conserved RNA helicase essential for germ cell development. The mouse PIWI family proteins MILI and MIWI2 are involved in production of Piwi-interacting RNAs (piRNAs) in fetal male germ cells through a ping-pong amplification cycle. Expression of retrotransposons is elevated in MILI- and MIWI2-deficient male germ cells due to defective de novo DNA methylation, which is presumably caused by impaired piRNA expression. Here, we report that essentially the same abnormalities are observed in MVH (mouse VASA homolog)-deficient mice. Comprehensive analysis of piRNAs in MVH-deficient fetal male germ cells showed that MVH plays crucial roles in the early phase of the ping-pong amplification cycle.

中文翻译：

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逆转录转座子的 piRNA 加工和基因沉默中的 MVH。

VASA 是一种进化上保守的 RNA 解旋酶，对生殖细胞发育至关重要。小鼠 PIWI 家族蛋白 MILI 和 MIWI2 通过乒乓扩增循环参与胎儿雄性生殖细胞中 Piwi 相互作用 RNA (piRNA) 的产生。由于从头 DNA 甲基化缺陷导致逆转录转座子在 MILI 和 MIWI2 缺陷的雄性生殖细胞中的表达升高，这可能是由 piRNA 表达受损引起的。在这里，我们报告在 MVH（小鼠 VASA 同源物）缺陷小鼠中观察到基本相同的异常。对 MVH 缺陷的胎儿男性生殖细胞中 piRNA 的综合分析表明，MVH 在乒乓扩增循环的早期阶段起着至关重要的作用。