In a previous study we described a Helitron transposon that apparently became one of the segments in the symbiotic Cotesia vestalis bracovirus (CvBV) from the parasitoid wasp C. vestalis. We presented evidence that this Helitron, named Hel_c35, invaded the C. vestalis genome through a horizontal transfer (HT) event from a dipteran and was later transferred horizontally from C. vestalis to a lepidopteran species. Based on the phylogeny of Hel_c35, we suggested that both HTs occurred in East Asia. We have also anticipated that, as more sequenced genomes from new species become available, more HTs involving Hel_c35 would be detected. Although the inclusion of Hel_c35 as a CvBV segment turned out to be a methodological artifact, the fact that Hel_c35 copies are present in the genomes of C. vestalis and other arthropods still remains. Here, we investigated the evolution of Hel_c35 in arthropods using an updated data set to reassess our previous findings. Most species (95%) included in the present work had their genomes sequenced after our initial study was published, thus representing new descriptions of taxa harboring Hel_c35. Our results expand considerably the number of putative HTs involving Hel_c35, with up to dozens of previously undescribed events, and suggest that the most recent HTs associated with C. vestalis took place in Europe. Considering the phylogenetic distribution of Hel_c35, and the evidence that its DNA sequences are present in the calyx fluid of C. vestalis and tissues from its parasitized host, we argue that many HT events were favored by the behavior of this wasp.

中文翻译：

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与寄生蜂相关的 Helitron 转座子的多次水平转移

在之前的一项研究中，我们描述了一个 Helitron 转座子，它显然成为来自寄生蜂 C. vestalis 的共生 Cotesia vestalis bracovirus (CvBV) 中的一个片段。我们提供的证据表明，这个名为 Hel_c35 的 Helitron 通过来自双翅目的水平转移 (HT) 事件侵入了维斯塔利斯基因组，后来从维斯塔利斯水平转移到了鳞翅目物种。基于 Hel_c35 的系统发育，我们认为这两个 HT 都发生在东亚。我们还预计，随着更多来自新物种的测序基因组变得可用，将检测到更多涉及 Hel_c35 的 HT。尽管将 Hel_c35 作为 CvBV 片段纳入结果证明是一种方法论伪影，但 Hel_c35 拷贝存在于 C.vestalis 和其他节肢动物的基因组中的事实仍然存在。这里，我们使用更新的数据集研究了节肢动物中 Hel_c35 的进化，以重新评估我们之前的发现。目前工作中包括的大多数物种（95%）在我们的初步研究发表后对其基因组进行了测序，因此代表了对含有 Hel_c35 的分类群的新描述。我们的结果大大增加了涉及 Hel_c35 的假定 HT 的数量，多达数十个以前未描述的事件，并表明与 C.vestalis 相关的最新 HT 发生在欧洲。考虑到 Hel_c35 的系统发育分布，以及它的 DNA 序列存在于 C.vestalis 的花萼液和寄生宿主的组织中的证据，我们认为许多 HT 事件受到这种黄蜂行为的青睐。