The evolution of genic piRNA cluster loci expression patterns

This study examines the conservation of Piwi-interacting RNA (piRNA) clusters that come from protein coding gene transcripts. By sequencing small RNA libraries from gonad tissues of Drosophilids and Glires we discover a diverse set of genic piRNA clusters conserved across animals. This dataset reveals new expression patterns for genic piRNA clusters and examines whether changing piRNA expression patterns correlates with sequence changes in piRNA cluster genomic sequence across a variety of animal species. We dissected gonad tissues consisting of ovaries from wildtype adult Drosophilids (D.melanogaster, D.erecta, D.yakuba, D.virilis) and testes from wildtype pre-pubsecent and adult mouse and rats. Adult testes from rabbits were purchased from Pel-Freez Biologicals. Total or immunopreciptated RNAs were extracted from the pulvirized gonad tissues of Drosophilids and Glires. Small RNAs were purified from these samples, converted into cDNA libraries, and sequenced on an Illumina HiSeq2000.

本研究聚焦于源自蛋白质编码基因转录本的Piwi相互作用RNA（Piwi-interacting RNA，piRNA）簇的保守性分析。我们通过对果蝇类（Drosophilids）和啮齿类总目（Glires）的性腺组织构建小RNA文库并测序，发现了一套在动物界中保守且种类多样的基因源性piRNA簇。本数据集揭示了基因源性piRNA簇的全新表达模式，并探究了在多种动物物种中，piRNA表达模式的改变是否与piRNA簇基因组序列的序列变化存在相关性。我们解剖了多份性腺组织：包括野生型成年果蝇类（黑腹果蝇D.melanogaster、直立果蝇D.erecta、雅库巴果蝇D.yakuba、维尔果蝇D.virilis）的卵巢，以及野生型青春期前与成年小鼠、大鼠的睾丸。成年兔睾丸样本购自Pel-Freez Biologicals公司。从粉碎后的果蝇类和啮齿类总目性腺组织中提取总RNA或经免疫沉淀富集的RNA。从上述样本中纯化小RNA，构建cDNA文库，并在Illumina HiSeq2000测序平台上完成测序。