Virus-host associations are usually viewed as parasitic, but several studies in recent years have reported examples of viruses that benefit host organisms. The Polydnaviridae are of particular interest because these viruses are all obligate mutualists of insects called parasitoid wasps. Parasitoids develop during their immature stages by feeding inside the body of other insects, which serve as their hosts. Polydnaviruses are vertically transmitted as proviruses through the germ line of wasps but also function as gene delivery vectors that wasps rely upon to genetically manipulate the hosts they parasitize. Here we review the evolutionary origin of polydnaviruses, the organization and function of their genomes, and some of their roles in parasitism.

中文翻译：

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Polydnaviruses：自然的遗传工程师。

病毒与宿主的关联通常被视为寄生虫，但是近年来的一些研究报告了有益于宿主生物的病毒实例。Polydnaviridae是特别令人感兴趣的，因为这些病毒都是专一的昆虫共生者，称为寄生蜂。寄生虫通过在其他昆虫体内觅食而发展为幼虫，这些昆虫是它们的宿主。Polydnaviruses作为原病毒通过黄蜂的种系垂直传播，但也起黄蜂依赖的基因传递载体的作用，对它们寄生的宿主进行基因操作。在这里，我们回顾了polydnaviruses的进化起源，其基因组的组织和功能以及它们在寄生中的作用。