Le Thomas Adrien, Marinov Georgi K, Aravin Alexei A
California Institute of Technology, Division of Biology and Biological Engineering, 147-75, 1200 East California Boulevard, Pasadena, CA 91125, USA; Ecole Doctorale Complexité du Vivant, Université Pierre et Marie Curie, 4 place Jussieu, 75005 Paris, France.
California Institute of Technology, Division of Biology and Biological Engineering, 147-75, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Cell Rep. 2014 Sep 25;8(6):1617-1623. doi: 10.1016/j.celrep.2014.08.013. Epub 2014 Sep 4.
Piwi-interacting (pi)RNAs repress diverse transposable elements in germ cells of Metazoa and are essential for fertility in both invertebrates and vertebrates. The precursors of piRNAs are transcribed from distinct genomic regions, the so-called piRNA clusters; however, how piRNA clusters are differentiated from the rest of the genome is not known. To address this question, we studied piRNA biogenesis in two D. virilis strains that show differential ability to generate piRNAs from several genomic regions. We found that active piRNA biogenesis correlates with high levels of histone 3 lysine 9 trimethylation (H3K9me3) over genomic regions that give rise to piRNAs. Furthermore, piRNA biogenesis in the progeny requires the transgenerational inheritance of an epigenetic signal, presumably in the form of homologous piRNAs that are generated in the maternal germline and deposited into the oocyte. The inherited piRNAs enhance piRNA biogenesis through the installment of H3K9me3 on piRNA clusters.
与Piwi相互作用的（pi）RNA抑制后生动物生殖细胞中多种转座元件，对无脊椎动物和脊椎动物的生育能力至关重要。piRNA的前体从不同的基因组区域转录而来，即所谓的piRNA簇；然而，piRNA簇如何与基因组的其他部分区分开来尚不清楚。为了解决这个问题，我们研究了两种果蝇品系中的piRNA生物合成，这两种品系在从几个基因组区域产生piRNA的能力上存在差异。我们发现，活跃的piRNA生物合成与产生piRNA的基因组区域上高水平的组蛋白3赖氨酸9三甲基化（H3K9me3）相关。此外，子代中的piRNA生物合成需要表观遗传信号的跨代遗传，推测是以在母系生殖系中产生并沉积到卵母细胞中的同源piRNA的形式。遗传的piRNA通过在piRNA簇上安装H3K9me3来增强piRNA生物合成。
