Institut de Recherche sur la Biologie de l'Insecte, CNRS UMR 7261, Université François-Rabelais, , Parc de Grandmont, 37200 Tours, France.
Philos Trans R Soc Lond B Biol Sci. 2013 Aug 12;368(1626):20130051. doi: 10.1098/rstb.2013.0051. Print 2013 Sep 19.
The Polydnaviridae (PDV), including the Bracovirus (BV) and Ichnovirus genera, originated from the integration of unrelated viruses in the genomes of two parasitoid wasp lineages, in a remarkable example of convergent evolution. Functionally active PDVs represent the most compelling evolutionary success among endogenous viral elements (EVEs). BV evolved from the domestication by braconid wasps of a nudivirus 100 Ma. The nudivirus genome has become an EVE involved in BV particle production but is not encapsidated. Instead, BV genomes have co-opted virulence genes, used by the wasps to control the immunity and development of their hosts. Gene transfers and duplications have shaped BV genomes, now encoding hundreds of genes. Phylogenomic studies suggest that BVs contribute largely to wasp diversification and adaptation to their hosts. A genome evolution model explains how multidirectional wasp adaptation to different host species could have fostered PDV genome extension. Integrative studies linking ecological data on the wasp to genomic analyses should provide new insights into the adaptive role of particular BV genes. Forthcoming genomic advances should also indicate if the associations between endoparasitoid wasps and symbiotic viruses evolved because of their particularly intimate interactions with their hosts, or if similar domesticated EVEs could be uncovered in other parasites.
多 DNA 病毒科（PDV），包括柄眼病毒（BV）和微病毒属，起源于两种寄生蜂谱系基因组中无关病毒的整合，这是趋同进化的一个显著例子。具有功能活性的 PDV 代表了内源性病毒元件（EVEs）中最引人注目的进化成功。BV 是由杆状病毒通过 1 亿年前的驯化而产生的。该 nudivirus 基因组已成为一种 EVE，参与 BV 颗粒的产生，但不被包裹。相反，BV 基因组已经采用了毒力基因，被黄蜂用来控制其宿主的免疫和发育。基因转移和复制塑造了 BV 基因组，现在编码了数百个基因。系统基因组学研究表明，BV 对黄蜂的多样化和适应其宿主起到了重要作用。一个基因组进化模型解释了多方向的黄蜂对不同宿主物种的适应如何促进了 PDV 基因组的扩展。将黄蜂的生态数据与基因组分析联系起来的综合研究，应该为特定 BV 基因的适应性作用提供新的见解。即将到来的基因组学进展还应该表明，内寄生黄蜂和共生病毒之间的关联是由于它们与宿主的特别密切的相互作用而进化的，还是可以在其他寄生虫中发现类似的驯化 EVEs。
