Diverse RNA Viruses Discovered in Three Parasitoid Wasps of the Rice Weevil Sitophilus oryzae.
Diverse RNA Viruses Discovered in Three Parasitoid Wasps of the Rice Weevil Sitophilus oryzae.
复制标题
DOI：
10.1128/msphere.00331-21
复制
发表时间：
2021-05-05
期刊：
影响因子：
4.8
通讯作者：
Ye G
中科院分区：
文献类型：
--
作者：
Wang F;Yuan B;Xiao S;Zhang J;Jia W;Fang Q;Wang F;Song Q;Ye G
昆虫中RNA病毒的巨大多样性不断得到验证。寄生蜂作为农业生态系统中广泛使用的生防昆虫，也可能携带许多“好”的RNA病毒。本研究从三种能寄生和防治水稻象甲的小蜂（8种）、落叶松食蚜小蜂（3种）和秀丽隐翅虫（18种）的转录组中获得了许多病毒样片段。通过进一步的生物信息学分析和测序，我们鉴定了6种新的RNA病毒，并将其命名为WWPSRV-1，WWPSRV-2，AcPSRV-1，AcNSRV-1，AcNSRV-2和LdNSRV-1。PCR检测结果表明，WWPSRV-1和WWPSRV-2具有种间传播的可能性，尤其是WWPSRV-2，其在稻象成虫体内也存在。在系统发育上，这6种病毒中有3种似乎属于小核糖核酸病毒目：WWPSRV-1属于该目未指定的病毒科，而WWPSRV-2和AcPSRV-1分别属于黄病毒科和双链病毒科。在3种病毒编码的非结构蛋白中均发现了解旋酶、蛋白酶和RNA依赖的RNA聚合酶等保守结构域，它们的基因组由不同数目的开放阅读框（ORF）组成。AcNSRV-1和AcNSRV-2属于弹状病毒科，LdNSRV-1属于弹状病毒科。3种病毒的基因组至少含有5个ORF，编码蛋白质的顺序为：3′-N-P-M-G-L-5′。所有的开放阅读框被保守的基因间序列分开，可能调控转录终止和起始。本研究结果加深了对象甲小蜂中RNA病毒的了解，并为进一步研究象甲、象甲小蜂和RNA病毒之间的关系奠定了基础。昆虫中RNA病毒的巨大多样性不断得到验证。寄生蜂作为农业生态系统中广泛使用的生防昆虫，也可能携带许多“好”的RNA病毒。寄生蜂体内的一些RNA病毒已被报道影响寄主蜂或蜂的宿主。在这里，六个新的RNA病毒与完整的基因组被确定在三个寄生蜂的水稻象甲。其中一种病毒在稻象虫成虫中也被检测到。在系统发育学上，WWPSRV-1是第一个明确的诺拉样病毒在昆虫寄生蜂中的检测。WWPSRV-2和AcPSRV-1属于黄病毒科和双链病毒科，其中一些病毒可导致家蚕和蜜蜂的致死性感染。其他三种RNA病毒属于单负病毒目，其中包括许多众所周知的昆虫相关病毒。
The enormous diversity of RNA viruses in insects is continuously validated. Parasitoid wasps, as biocontrol insects which are widely used against insect pests in agroecosystems, may also carry many “good” RNA viruses. In this study, many virus-like fragments were obtained from transcriptomes of three wasp species, including Anisopteromalus calandrae (8), Lariophagus distinguendus (3), and Theocolax elegans (18), which can parasitize and control rice weevil Sitophilus oryzae, a serious insect pest of farm-stored grains. By further bioinformatic analysis and sequencing, we identified six novel RNA viruses with complete genomes and named them WWPSRV-1, WWPSRV-2, AcPSRV-1, AcNSRV-1, AcNSRV-2, and LdNSRV-1. PCR-based detection revealed that WWPSRV-1 and WWPSRV-2 had the possibility of interspecies virus transmission, especially WWPSRV-2, which was also present in the rice weevil adults. Phylogenetically, three out of these six viruses appeared to be members of order Picornavirales: WWPSRV-1 belonged to unassigned virus families of this order, whereas WWPSRV-2 and AcPSRV-1 belonged to families Iflaviridae and Dicistroviridae, respectively. The conserved picornavirus-typical domains helicase, protease, and RNA-dependent RNA polymerase could be found in the nonstructural protein encoded by the three viruses, whose genomes consisted of the different numbers of open reading frames (ORFs). The other three RNA viruses could be classified to order Mononegavirales: AcNSRV-1 and AcNSRV-2 belonged to family Lispiviridae, whereas LdNSRV-1 belonged to a big family Rhabdoviridae. The genomes of the three viruses contained at least five ORFs, encoding deduced proteins in the following order: 3′-N-P-M-G-L-5′. All the ORFs were separated by conserved intergenic sequences which likely regulated the transcription termination and initiation. Our findings enhance the understanding of RNA viruses in weevil wasps and set the foundation for the future study of the association among weevils, weevil wasps, and RNA viruses. IMPORTANCE The enormous diversity of RNA viruses in insects is continuously validated. Parasitoid wasps, as biocontrol insects which are widely used against insect pests in agroecosystems, may also carry many “good” RNA viruses. Some RNA viruses in parasitoid wasps have been reported to affect the host wasps or the wasps’ host. Here, six novel RNA viruses with complete genomes were identified in three parasitoid wasps of the rice weevil. One of these viruses was also detected in the rice weevil adults. Phylogenetically, WWPSRV-1 was the first unambiguous detection of Nora-like virus in insect parasitoids. WWPSRV-2 and AcPSRV-1 belong to families Iflaviridae and Dicistroviridae, some viruses of which can result in lethal infections in silkworms and honeybees. The other three RNA viruses belong to order Mononegavirales, which comprises many well-known insect-associated viruses.