遗传材料在非交配物种间的横向转移（HT）在细菌中很常见，并且越来越多地被认为是真核演化中的一个重要力量。
后生动物中迄今所介绍的大多数HT实例都涉及移动遗传元素（主要是转位子），但使得相差很大的物质间这种交换成为可能的机制却不清楚。现在，Gilbert等人发现，转位元素是通过在由不同物种共享的寄生虫的基因组中“搭便车”来在这些物种间传播的。
具体来说，长红锥蝽（Rhodnius prolixus）（一种以四足动物血液为食、是人类锥虫病传播媒介的虫子）的基因组中有四个截然不同的转位子家族，它们入侵包括负鼠和松鼠猴在内的一系列不同四足动物的基因组。这些转位子家族中的其中一个也存在于名为“静水椎实螺”的塘螺中，这种螺是感染很多脊椎动物的吸虫的一种传播媒介。(生物谷Bioon.com)
生物谷推荐原文出处：
Nature doi:10.1038/nature08939
A role for host–parasite interactions in the horizontal transfer of transposons across phyla
Clément Gilbert,Sarah Schaack,John K. Pace II,Paul J. Brindley& Cédric Feschotte
Horizontal transfer (HT), or the passage of genetic material between non-mating species, is increasingly recognized as an important force in the evolution of eukaryotic genomes1, 2. Transposons, with their inherent ability to mobilize and amplify within genomes, may be especially prone to HT3, 4, 5, 6, 7. However, the means by which transposons can spread across widely diverged species remain elusive. Here we present evidence that host–parasite interactions have promoted the HT of four transposon families between invertebrates and vertebrates. We found that Rhodnius prolixus, a triatomine bug feeding on the blood of various tetrapods and vector of Chagas’ disease in humans, carries in its genome four distinct transposon families that also invaded the genomes of a diverse, but overlapping, set of tetrapods. The bug transposons are ~98% identical and cluster phylogenetically with those of the opossum and squirrel monkey, two of its preferred mammalian hosts in South America. We also identified one of these transposon families in the pond snail Lymnaea stagnalis, a cosmopolitan vector of trematodes infecting diverse vertebrates, whose ancestral sequence is nearly identical and clusters with those found in Old World mammals. Together these data provide evidence for a previously hypothesized role of host–parasite interactions in facilitating HT among animals3, 7. Furthermore, the large amount of DNA generated by the amplification of the horizontally transferred transposons supports the idea that the exchange of genetic material between hosts and parasites influences their genomic evolution.
