Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
RNA. 2018 Jul;24(7):899-907. doi: 10.1261/rna.065839.118. Epub 2018 Apr 20.
RNAi has revolutionized genetic research, and is being commercialized as an insect pest control technology. Mechanisms exploited for this purpose are antiviral and therefore rapidly evolving. Ideally RNAi will also be used for noninsect pests; however, differences in RNAi biology make this uncertain. (two-spotted spider mite) is a destructive noninsect pest, which has a proclivity to develop pesticide resistance. Here we provide a comprehensive study of the endogenous RNAi pathways of spider mites to inform design of exogenous RNAi triggers. This effort revealed unexpected roles for small RNAs and novel genome surveillance pathways. Spider mites have an expanded RNAi machinery relative to insects, encoding RNA dependent RNA polymerase (Rdrp) and extra Piwi-class effectors. Through analyzing transcriptome data we explored small RNA biogenesis, and discovered five siRNA loci that appear central to genome surveillance. These RNAs are expressed in the gonad, which we hypothesize to trigger production of piRNAs for control of transposable elements (TEs). This work highlights the need to investigate endogenous RNAi biology as lessons from model organisms may not hold in other species, impacting development of an RNAi strategy.
RNAi 技术彻底改变了遗传研究，并正在被商业化作为一种害虫防治技术。为此目的而利用的机制是抗病毒的，因此正在迅速进化。理想情况下，RNAi 也将用于非昆虫害虫；然而，RNAi 生物学的差异使得这一点不确定。（二斑叶螨）是一种具有破坏性的非昆虫害虫，它有产生抗药性的倾向。在这里，我们对蜘蛛螨的内源性 RNAi 途径进行了全面研究，为设计外源性 RNAi 触发因素提供了信息。这项工作揭示了小 RNA 和新的基因组监测途径的意外作用。与昆虫相比，蜘蛛螨具有扩展的 RNAi 机制，编码 RNA 依赖性 RNA 聚合酶 (Rdrp) 和额外的 Piwi 类效应物。通过分析转录组数据，我们探索了小 RNA 的生物发生，并发现了五个似乎对基因组监测至关重要的 siRNA 基因座。这些 RNA 在性腺中表达，我们假设它们会触发 piRNA 的产生，以控制转座元件 (TEs)。这项工作强调了需要研究内源性 RNAi 生物学，因为来自模式生物的经验教训在其他物种中可能并不适用，这会影响 RNAi 策略的发展。
