期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：4
页码：1606-1611
DOI：10.1073/pnas.0911353107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In response to infection, invertebrates process replicating viral RNA genomes into siRNAs of discrete sizes to guide virus clearance by RNA interference. Here, we show that viral siRNAs sequenced from fruit fly, mosquito, and nematode cells were all overlapping in sequence, suggesting a possibility of using siRNAs for viral genome assembly and virus discovery. To test this idea, we examined contigs assembled from published small RNA libraries and discovered five previously undescribed viruses from cultured Drosophila cells and adult mosquitoes, including three with a positive-strand RNA genome and two with a dsRNA genome. Notably, four of the identified viruses exhibited only low sequence similarities to known viruses, such that none could be assigned into an existing virus genus. We also report detection of virus-derived PIWI-interacting RNAs (piRNAs) in Drosophila melanogaster that have not been previously described in any other host species and demonstrate viral genome assembly from viral piRNAs in the absence of viral siRNAs. Thus, this study provides a powerful culture-independent approach for virus discovery in invertebrates by assembling viral genomes directly from host immune response products without prior virus enrichment or amplification. We propose that invertebrate viruses discovered by this approach may include previously undescribed human and vertebrate viral pathogens that are transmitted by arthropod vectors.
