Rodríguez-Pérez Mario A, Beckage Nancy E
Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa Tamaulipas, México.
Rev Latinoam Microbiol. 2006 Jan-Mar;48(1):31-43.
Polydnaviruses are genetic symbionts of wasp endoparasitoids belonging to the hymenopteran families Ichneumonidae (ichnoviruses) and Braconidae (bracoviruses). They exist as proviruses integrated in the wasp's chromosomal genome, which then excise and undergo replication during the stage of adult development of the wasp. During wasp oviposition into their caterpillar host, the fully formed virus particles are injected along the parasitoid's eggs into the host hemocoel, where the eggs hatch and undergo larval development. The primary function of the polydnavirus is to trigger host immunosuppression so that host hemocytes are prevented from encapsulating the parasitoid's eggs and/or larvae. Polydnavirus transcripts are expressed following parasitization and alter host hemocyte adhesive properties that prevents encapsulation; in some species, viral gene expression triggers host hemocyte apoptosis, thereby rendering the host immunosuppressed. This review summarizes the major features of polydnaviruses and provides a global view of their functions in the lepidopteran hosts of the parasitoid wasps that carry them both as integrated viral sequences in their genome and as free virus to function physiologically in host regulation following parasitization of the host.
多DNA病毒是膜翅目茧蜂科（茧蜂病毒）和茧蜂科（杆状病毒）黄蜂内寄生蜂的遗传共生体。它们以原病毒的形式整合在黄蜂的染色体基因组中，然后在黄蜂成虫发育阶段切除并进行复制。在黄蜂将卵产入毛虫宿主的过程中，完全形成的病毒颗粒会随着寄生蜂的卵一起注入宿主血腔，卵在那里孵化并进行幼虫发育。多DNA病毒的主要功能是引发宿主免疫抑制，从而防止宿主血细胞包裹寄生蜂的卵和/或幼虫。多DNA病毒转录本在寄生后表达，并改变宿主血细胞的黏附特性以防止包裹；在某些物种中，病毒基因表达会引发宿主血细胞凋亡，从而使宿主免疫抑制。本综述总结了多DNA病毒的主要特征，并全面介绍了它们在携带它们的寄生蜂的鳞翅目宿主中的功能，这些寄生蜂既将它们作为基因组中的整合病毒序列，也作为游离病毒在宿主被寄生后在宿主调节中发挥生理作用。
