A Mutualistic Poxvirus Exhibits Convergent Evolution with Other Heritable Viruses in Parasitoid Wasps
A Mutualistic Poxvirus Exhibits Convergent Evolution with Other Heritable Viruses in Parasitoid Wasps
复制标题
DOI：
10.1128/jvi.02059-19
复制
发表时间：
2020-04-01
影响因子：
5.4
通讯作者：
Burke, Gaelen R.
中科院分区：
文献类型：
--
作者：
Coffman, Kelsey A.;Harrell, Taylor C.;Burke, Gaelen R.
对于被称为拟寄生黄蜂的昆虫来说，作为寄生虫的成功发育会导致宿主昆虫的死亡。由于这种致命的相互作用，黄蜂和它们的宿主共同进化出了在这场进化军备竞赛中获得优势的策略。虽然通常被认为是严格的病原体，但一些病毒在寄生蜂谱系中建立了持续感染，并在寄生蜂寄生期间对寄生蜂有益。病毒和拟寄生蜂之间的遗传关联已经独立进化了多次，但这些系统中的大多数在病毒起源、病毒传播和复制策略以及病毒与宿主昆虫之间的相互作用方面仍未得到充分研究。在这里，我们报告了详细的表征Diachasmimorpha longicaudata昆虫痘病毒（DIEPV），一种在Diachasmimorpha longicaudata黄蜂毒液腺中发现的痘病毒。我们的研究结果表明，与其他寄生性病毒元素相比，DIEPV具有相似但不同的传播和复制动力学，包括病毒在黄蜂体内的垂直传播，以及病毒在雌性黄蜂和果蝇宿主中的复制。功能分析表明，DIEPV在苍蝇宿主中具有很高的毒力，与具有典型病毒载量的黄蜂相比，没有DIEPV的黄蜂的寄生成功率严重降低。综上所述，本研究提供的数据说明了有益病毒进化的一个新案例，其中一种独特起源的病毒与其他与寄生蜂相关的病毒元件经历了趋同进化，在整个寄生过程中提供类似的功能。病毒通常被认为是致病因子，但在被称为拟寄生蜂的昆虫中已经发现了几种有益的病毒成分。这些病毒衍生的实体通过黄蜂一代又一代地传递，并增强了黄蜂寄生生命周期的成功。迄今为止研究的许多类寄生虫-病毒伙伴关系在这一现象的独立病例中表现出共同的特征，包括病毒的母婴传播途径，病毒复制的时间和地点有限，以及病毒活性对黄蜂存活的积极影响。我们对在长尾拟寄生蜂中发现的痘病毒——长尾拟寄生蜂Diachasmimorpha longicaudata虫痘病毒（DIEPV）的鉴定，代表了有益病毒进化的一个新例子。在这里，我们发现DIEPV与已知的类寄生虫病毒元素具有功能相似性，这支持了它在寄生过程中的类似作用。我们的研究结果也显示了独特的差异，表明DIEPV比寄生蜂中描述的其他长期病毒关联更自主。
For insects known as parasitoid wasps, successful development as a parasite results in the death of the host insect. As a result of this lethal interaction, wasps and their hosts have coevolved strategies to gain an advantage in this evolutionary arms race. Although normally considered to be strict pathogens, some viruses have established persistent infections within parasitoid wasp lineages and are beneficial to wasps during parasitism. Heritable associations between viruses and parasitoid wasps have evolved independently multiple times, but most of these systems remain largely understudied with respect to viral origin, transmission and replication strategies of the virus, and interactions between the virus and host insects. Here, we report a detailed characterization of Diachasmimorpha longicaudata entomopoxvirus (DIEPV), a poxvirus found within the venom gland of Diachasmimorpha longicaudata wasps. Our results show that DIEPV exhibits similar but distinct transmission and replication dynamics compared to those of other parasitoid viral elements, including vertical transmission of the virus within wasps, as well as virus replication in both female wasps and fruit fly hosts. Functional assays demonstrate that DIEPV is highly virulent within fly hosts, and wasps without DIEPV have severely reduced parasitism success compared to those with a typical viral load. Taken together, the data presented in this study illustrate a novel case of beneficial virus evolution, in which a virus of unique origin has undergone convergent evolution with other viral elements associated with parasitoid wasps to provide an analogous function throughout parasitism.IMPORTANCE Viruses are generally considered to be disease-causing agents, but several instances of beneficial viral elements have been identified in insects called parasitoid wasps. These virus-derived entities are passed on through wasp generations and enhance the success of the wasps' parasitic life cycle. Many parasitoid-virus partnerships studied to date exhibit common features among independent cases of this phenomenon, including a mother-to-offspring route of virus transmission, a restricted time and location for virus replication, and a positive effect of virus activity on wasp survival. Our characterization of Diachasmimorpha longicaudata entomopoxvirus (DIEPV), a poxvirus found in Diachasmimorpha longicaudata parasitoid wasps, represents a novel example of beneficial virus evolution. Here, we show that DIEPV exhibits functional similarities to known parasitoid viral elements that support its comparable role during parasitism. Our results also demonstrate unique differences that suggest DIEPV is more autonomous than other long-term viral associations described in parasitoid wasps.