Piwi-interacting RNAs (piRNAs) are an animal-specific class of small non-coding RNAs that are generated via a biogenesis pathway distinct from small interfering RNAs (siRNAs) and microRNAs (miRNAs). There are variations in piRNA biogenesis that depend on several factors, such as the cell type (germline or soma), the organism, and the purpose for which they are being produced, such as transposon-targeting, viral-targeting, or gene-derived piRNAs. Interestingly, the genes involved in the PIWI/piRNA pathway are more rapidly evolving compared with other RNA interference (RNAi) genes. In this review, the role of the piRNA pathway in the antiviral response is reviewed based on recent findings in insect models such as Drosophila, mosquitoes, midges and the silkworm, Bombyx mori. We extensively discuss the special features that characterize host-virus piRNA responses with respect to the proteins and the genes involved, the viral piRNAs' sequence characteristics, the target strand orientation biases as well as the viral piRNA target hotspots across the viral genomes. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > RNAi: Mechanisms of Action Regulatory RNAs/RNAi/Riboswitches > Biogenesis of Effector Small RNAs.

中文翻译：

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针对昆虫中病毒的PIWI途径。

皮维相互作用RNA（piRNA）是一类动物特定的非编码小RNA，它们是通过不同于小干扰RNA（siRNA）和microRNA（miRNA）的生物发生途径生成的。piRNA生物发生方面的变化取决于多种因素，例如细胞类型（生殖细胞或体细胞），生物体以及产生它们的目的，例如转座子靶向，病毒靶向或基因衍生piRNA。有趣的是，与其他RNA干扰（RNAi）基因相比，参与PIWI / piRNA途径的基因发展更为迅速。在这篇综述中，基于昆虫模型（如果蝇，蚊子，mid和家蚕）的最新发现，对piRNA途径在抗病毒应答中的作用进行了综述。我们广泛讨论了表征宿主病毒piRNA对涉及的蛋白质和基因的特殊功能，病毒piRNA的序列特征，目标链方向的偏向以及整个病毒基因组中的病毒piRNA目标热点。本文归类于：调节RNA / RNAi /核糖开关> RNAi：作用机理调节RNA / RNAi /核糖开关>效应子小RNA的生物发生。