The Complete Genome of Chelonus insularis Reveals Dynamic Arrangement of Genome Components in Parasitoid Wasps That Produce Bracoviruses
The Complete Genome of Chelonus insularis Reveals Dynamic Arrangement of Genome Components in Parasitoid Wasps That Produce Bracoviruses
复制标题
DOI：
10.1128/jvi.01573-21
复制
发表时间：
2022-03-09
影响因子：
5.4
通讯作者：
Burke, Gaelen R.
中科院分区：
文献类型：
--
作者：
Mao, Meng;Strand, Michael R.;Burke, Gaelen R.
茧状病毒是病毒内源化的一个显著例子，因为来自裸壳病毒祖先的大量基因组继续产生病毒体，数千种黄蜂物种依赖这些病毒体来寄生宿主。了解这些基因是如何相互作用并被黄蜂利用以获得新功能的，是病毒进化研究中的一个热点。小腹蜂利用裸病毒基因产生复制缺陷型病毒体，雌性小腹蜂利用这些病毒体将毒力基因转移到被寄生的宿主。微胃复合体进一步由6个亚科组成，类似于50，000个物种，但目前对BV基因库存和组织的理解主要来自对产生M的微胃亚科中的两种黄蜂物种（Microplitis demolitor和Cotesia congregata）的分析。demolitor BV（MdBV）和C.聚集体BV（CcBV）。值得注意的是，MdBV和CcBV的一些基因组特征自M. demolitor和C.与5300万年前（MYA）相似。然而，目前还不清楚这些保守的特征是否更广泛地反映了BV的进化，因为在Microgastrinae之外的任何Microgastraid黄蜂都不存在完整的基因组。在这方面，龟鳖亚科是最感兴趣的，因为它最早从微胃亚科（类似于85百万年）后，nudivirus祖先的内源化。在这里，我们提出了完整的基因组的龟insularis，这是一个卵幼虫寄生在龟亚科，产生C。insularis BV（CinsBV）。我们报道了裸病毒基因在C。insularis是保守的，但与M. demolitor和C.集合。相反，CinsBV前病毒片段与MdBV和CcBV共享组织特征，但毒力基因库几乎没有重叠。总而言之，我们的研究结果指出了裸病毒基因的保守库存和一组动态的毒力基因的成功寄生的主机的功能的重要性。我们的研究结果还表明，以前在MdBV和CcBV中发现的组织特征可能不是BV病毒体形成所必需的。重要性茧病毒是病毒内源化的一个显著例子，因为来自裸壳病毒祖先的大量基因组继续产生病毒体，成千上万的黄蜂物种依赖这些病毒体来寄生宿主。了解这些基因如何相互作用，并已增选黄蜂的新功能是在病毒进化研究的广泛兴趣。这项工作的特点，在寄生蜂Chelonus insularis，它与现有的黄蜂基因组捕获了很大一部分的黄蜂物种之间的多样性，产生bracoviruses的bracovirus基因组成分。研究结果提供了关于不同黄蜂中杆状病毒基因组成分如何组织的新信息，同时也提供了关于功能所需关键特征的更多见解。
Bracoviruses are a remarkable example of virus endogenization, because large sets of genes from a nudivirus ancestor continue to produce virions that thousands of wasp species rely upon to parasitize hosts. Understanding how these genes interact and have been coopted by wasps for novel functions is of broad interest in the study of virus evolution.Bracoviruses (BVs) are endogenized nudiviruses in parasitoid wasps of the microgastroid complex (family Braconidae). Microgastroid wasps have coopted nudivirus genes to produce replication-defective virions that females use to transfer virulence genes to parasitized hosts. The microgastroid complex further consists of six subfamilies and similar to 50,000 species but current understanding of BV gene inventories and organization primarily derives from analysis of two wasp species in the subfamily Microgastrinae (Microplitis demolitor and Cotesia congregata) that produce M. demolitor BV (MdBV) and C. congregata BV (CcBV). Notably, several genomic features of MdBV and CcBV remain conserved since divergence of M. demolitor and C. congregata similar to 53 million years ago (MYA). However, it is unknown whether these conserved traits more broadly reflect BV evolution, because no complete genomes exist for any microgastroid wasps outside the Microgastrinae. In this regard, the subfamily Cheloninae is of greatest interest because it diverged earliest from the Microgastrinae (similar to 85 MYA) after endogenization of the nudivirus ancestor. Here, we present the complete genome of Chelonus insularis, which is an egg-larval parasitoid in the Cheloninae that produces C. insularis BV (CinsBV). We report that the inventory of nudivirus genes in C. insularis is conserved but are dissimilarly organized compared to M. demolitor and C. congregata. Reciprocally, CinsBV proviral segments share organizational features with MdBV and CcBV but virulence gene inventories exhibit almost no overlap. Altogether, our results point to the functional importance of a conserved inventory of nudivirus genes and a dynamic set of virulence genes for the successful parasitism of hosts. Our results also suggest organizational features previously identified in MdBV and CcBV are likely not essential for BV virion formation. IMPORTANCE Bracoviruses are a remarkable example of virus endogenization, because large sets of genes from a nudivirus ancestor continue to produce virions that thousands of wasp species rely upon to parasitize hosts. Understanding how these genes interact and have been coopted by wasps for novel functions is of broad interest in the study of virus evolution. This work characterizes bracovirus genome components in the parasitoid wasp Chelonus insularis, which together with existing wasp genomes captures a large portion of the diversity among wasp species that produce bracoviruses. Results provide new information about how bracovirus genome components are organized in different wasps while also providing additional insights on key features required for function.