Discrete small RNA-generating loci as master regulators of transposon activity in Drosophila
Discrete small RNA-generating loci as master regulators of transposon activity in Drosophila
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DOI：
10.1016/j.cell.2007.01.043
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发表时间：
2007-03-23
期刊：
影响因子：
64.5
通讯作者：
Hannon, Gregory J.
中科院分区：
文献类型：
--
作者：
Brennecke, Julius;Aravin, Alexei A.;Hannon, Gregory J.
果蝇Piwi家族蛋白与转座子控制有关。在这里，我们研究了与每个果蝇Piwi蛋白相关的Piwi相互作用RNA（piRNA），发现Piwi和Aubergine主要与转座子反义的RNA结合，而Ago3复合物主要含有正义piRNA。与哺乳动物一样，大多数果蝇piRNA来源于离散的基因组基因座。这些基因座主要包括有缺陷的转座子序列，并且一些先前已被鉴定为转座子活性的主调节子。我们的数据表明，异染色质皮尔纳基因座与潜在活性的常染色质转座子相互作用，形成一个自适应系统的转座子控制。有义和反义皮尔纳群体之间的互补关系表明扩增环，其中每个piRNA指导的切割事件产生新皮尔纳的5'端。因此，在转座子mRNA切割后形成的有义piRNA可以通过引导转录物从主控制基因座切割来增强与活性元件互补的反义piRNA的产生。
Drosophila Piwi-family proteins have been implicated in transposon control. Here, we examine piwi-interacting RNAs (piRNAs) associated with each Drosophila Piwi protein and find that Piwi and Aubergine bind RNAs that are predominantly antisense to transposons, whereas Ago3 complexes contain predominantly sense piRNAs. As in mammals, the majority of Drosophila piRNAs are derived from discrete genomic loci. These loci comprise mainly defective transposon sequences, and some have previously been identified as master regulators of transposon activity. Our data suggest that heterochromatic piRNA loci interact with potentially active, euchromatic transposons to form an adaptive system for transposon control. Complementary relationships between sense and antisense piRNA populations suggest an amplification loop wherein each piRNA-directed cleavage event generates the 5' end of a new piRNA. Thus, sense piRNAs, formed following cleavage of transposon mRNAs may enhance production of antisense piRNAs, complementary to active elements, by directing cleavage of transcripts from master control loci.