Horizontal transmission between distantly related species has been used to explain how Wolbachia infect multiple species at astonishing rates despite the selection for resistance. Recently, a terrestrial isopod species was found to be infected by an unusual strain of supergroup F Wolbachia. However, only Wolbachia of supergroup B is typically found in isopods. One possibility is that these isopods acquired the infection because of their recurrent contact with termites—a group with strong evidence of infection by supergroup F Wolbachia. Thus, our goals were: (1) check if the infection was an isolated case in isopods, or if it revealed a broader pattern; (2) search for Wolbachia infection in the termites within Brazil; and (3) look for evidence consistent with horizontal transmission between isopods and termites. We collected Neotroponiscus terrestrial isopods and termites along the Brazilian coastal Atlantic forest. We sequenced and identified the Wolbachia strains found in these groups using coxA, dnaA, and fpbA genes. We constructed phylogenies for both bacteria and host taxa and tested for coevolution. We found the supergroup F Wolbachia in other species and populations of Neotroponiscus, and also in Nasutitermes and Procornitermes termites. The phylogenies showed that, despite the phylogenetic distance between isopods and termites, the Wolbachia strains clustered together. Furthermore, cophylogenetic analyses showed significant jumps of Wolbachia between terrestrial isopods and termites. Thus, our study suggests that the horizontal transmission of supergroup F Wolbachia between termites and terrestrial isopods is likely. Our study also helps understanding the success and worldwide distribution of this symbiont.

尽管选择了抗性，但远缘相关物种之间的水平传播已被用来解释沃尔巴克氏体如何以惊人的速度感染多个物种。最近，发现一种陆地等足类动物被一种不寻常的超群 F Wolbachia菌株感染。然而，在等足类动物中通常只发现超群 B 的沃尔巴克氏体。一种可能性是，这些等足类动物因反复与白蚁接触而获得感染——这些白蚁有强有力的证据表明被超群 F Wolbachia 感染。因此，我们的目标是：（1）检查感染是否是等足类动物的孤立病例，或者它是否揭示了更广泛的模式；(2)寻找沃尔巴克氏体巴西境内白蚁感染；(3) 寻找与等足类动物和白蚁之间水平传播相一致的证据。我们沿着巴西沿海大西洋森林收集了Neotroponiscus陆地等足类动物和白蚁。我们使用coxA、dnaA和fpbA基因对在这些组中发现的Wolbachia菌株进行了测序和鉴定。我们为细菌和宿主分类群构建了系统发育并测试了共同进化。我们在其他物种和种群中发现了超群 F Wolbachia新热带鱼属, 以及Nasutitermes和Procornitermes 。白蚁。系统发育表明，尽管等足类动物和白蚁之间的系统发育距离很远，但沃尔巴克氏体菌株聚集在一起。此外，系统发育分析显示Wolbachia在陆地等足类动物和白蚁之间有显着的跳跃。因此，我们的研究表明，超群 F Wolbachia在白蚁和陆地等足动物之间的水平传播是可能的。我们的研究还有助于了解这种共生体的成功和全球分布。