State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Ministry of Agriculture Key Laboratory of Biotechnology in Plant Protection, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang Province, China.
PLoS One. 2013 Jun 11;8(6):e66007. doi: 10.1371/journal.pone.0066007. Print 2013.
Replication of RNA viruses in insect cells triggers an antiviral defense that is mediated by RNA interference (RNAi) which generates viral-derived small interfering RNAs (siRNAs). However, it is not known whether an antiviral RNAi response is also induced in insects by reoviruses, whose double-stranded RNA genome replication is thought to occur within core particles. Deep sequencing of small RNAs showed that when the small brown planthopper (Laodelphax striatellus) was infected by Rice black-streaked dwarf virus (RBSDV) (Reoviridae; Fijivirus), more viral-derived siRNAs accumulated than when the vector insect was infected by Rice stripe virus (RSV), a negative single-stranded RNA virus. RBSDV siRNAs were predominantly 21 and 22 nucleotides long and there were almost equal numbers of positive and negative sense. RBSDV siRNAs were frequently generated from hotspots in the 5'- and 3'-terminal regions of viral genome segments but these hotspots were not associated with any predicted RNA secondary structures. Under laboratory condition, L. striatellus can be infected simultaneously with RBSDV and RSV. Double infection enhanced the accumulation of particular genome segments but not viral coat protein of RBSDV and correlated with an increase in the abundance of siRNAs derived from RBSDV. The results of this study suggest that reovirus replication in its insect vector potentially induces an RNAi-mediated antiviral response.
昆虫细胞中 RNA 病毒的复制会触发抗病毒防御，该防御由 RNA 干扰 (RNAi) 介导，产生病毒衍生的小干扰 RNA (siRNA)。然而，双股 RNA 基因组复制被认为发生在核心颗粒内的呼肠孤病毒是否也会在昆虫中引发抗病毒 RNAi 反应尚不清楚。小 RNA 的深度测序表明，当褐飞虱（Laodelphax striatellus）感染水稻黑条矮缩病毒 (RBSDV)（呼肠孤病毒科；斐济病毒属）时，积累的病毒衍生 siRNA 比感染水稻条纹病毒 (RSV)（负单链 RNA 病毒）时更多。RBSDV siRNA 主要为 21 和 22 个核苷酸长，正负链的数量几乎相等。RBSDV siRNA 经常从病毒基因组片段 5' 和 3' 末端区域的热点产生，但这些热点与任何预测的 RNA 二级结构无关。在实验室条件下，褐飞虱可以同时感染 RBSDV 和 RSV。双重感染增强了特定基因组片段的积累，但不会增强 RBSDV 外壳蛋白的积累，这与 RBSDV 衍生 siRNA 的丰度增加有关。本研究的结果表明，呼肠孤病毒在其昆虫载体中的复制可能会引发 RNAi 介导的抗病毒反应。
