Identification and characterization of two novel classes of small RNAs in the mouse germline: retrotransposon-derived siRNAs in oocytes and germline small RNAs in testes
Identification and characterization of two novel classes of small RNAs in the mouse germline: retrotransposon-derived siRNAs in oocytes and germline small RNAs in testes
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DOI：
10.1101/gad.1425706
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发表时间：
2006-07-01
影响因子：
10.5
通讯作者：
Imai, Hiroshi
中科院分区：
文献类型：
--
作者：
Watanabe, Toshiaki;Takeda, Atsushi;Imai, Hiroshi
在包括酵母，植物和动物在内的许多生物中都发现了尺寸在18至30个核苷酸（NT）之间的小RNA。小RNA通过翻译抑制，mRNA降解和染色质修饰参与了基因表达的调节。在哺乳动物中，microRNA（miRNA）是唯一表征良好的小型RNA。在这里，我们在小鼠种系中确定了两类小型RNA。一个类别由小鼠卵母细胞的20至24-nt小干扰RNA（siRNA）组成，这些卵母细胞源自包括线，正弦和LTR逆转转座子在内的恢复元素。在注射到全生长的卵母细胞中时，将逆转录子衍生的序列添加到记者mRNA的3'未翻译区域（UTR）中会显着不稳定mRNA。这些结果表明，逆转录子通过小鼠卵母细胞的RNAi途径抑制。另一个新型的小RNA类别是睾丸的26至30 nt种系小RNA（GSRNA）。 GSRNA以发育调控的方式表达在精子发生过程中，映射到簇中的基因组，并具有较强的链偏差。这些特征让人联想到类似于23至24-nt小的RNA和秀丽隐杆线虫X簇小RNA的四膜膜。多种动物中可能存在保守的新型小RNA途径。
Small RNAs ranging in size between 18 and 30 nucleotides (nt) are found in many organisms including yeasts, plants, and animals. Small RNAs are involved in the regulation of gene expression through translational repression, mRNA degradation, and chromatin modification. In mammals, microRNAs (miRNAs) are the only small RNAs that have been well characterized. Here, we have identified two novel classes of small RNAs in the mouse germline. One class consists of similar to 20- to 24-nt small interfering RNAs (siRNAs) from mouse oocytes, which are derived from retroelements including LINE, SINE, and LTR retrotransposons. Addition of retrotransposon-derived sequences to the 3' untranslated region (UTR) of a reporter mRNA destabilizes the mRNA significantly when injected into full-grown oocytes. These results suggest that retrotransposons are suppressed through the RNAi pathway in mouse oocytes. The other novel class of small RNAs is 26- to 30-nt germline small RNAs (gsRNAs) from testes. gsRNAs are expressed during spermatogenesis in a developmentally regulated manner, are mapped to the genome in clusters, and have strong strand bias. These features are reminiscent of Tetrahymena similar to 23- to 24-nt small RNAs and Caenorhabditis elegans X-cluster small RNAs. A conserved novel small RNA pathway may be present in diverse animals.