シロアリとその細胞内バクテリアの共生

许多节肢动物被胞内细菌感染，如Wolbachia，Cardinium和Rickettsia。这些细菌对宿主的生态和进化有着深远的影响，并进化出了几种策略来增加自己的生殖适应性，有时会为宿主付出代价。并不是所有的都是寄生虫：有些进化出了与宿主的互惠关系。很少有研究大规模调查沃尔巴克氏体的流行病学状况。本研究通过对500余种2392个白蚁样本进行全基因组测序，研究了南美白蚁中该病毒的感染动态，并利用有丝分裂基因组和核超保守元件（UCEs）重建了南美白蚁的生殖发育。在本项目中，针对总共50616个UCE的诱饵是专门为白蚁设计的。基于UCE的同源性恢复具有高度支持的深层次和浅层次的关系恢复至今只有转录组启用的数据集，从而证明我们的诱饵集是可靠的和信息丰富的。阅读图谱方法表明，1205个样本被Wolbachia感染，其中两个超级群体主导了南美的感染景观。在少数情况下，大多数来自单一物种的样本，具有不同的生活方式，在整个范围内都受到感染。因此，这种亲密的共生关系可能解释了这些物种的生态成功（准备中）。这些结果开辟了功能基因组学的道路，并揭示了白蚁-沃尔巴克氏体共生的真实性质。

Many arthropods are infected by intracellular bacteria, such as Wolbachia, Cardinium and Rickettsia. These bacteria have profound influences on the ecology and evolution of their host and evolved several strategies to increase their own reproductive fitness, sometimes with costs for their hosts. Not all are parasites: some evolved mutualistic relationships with their hosts. Few studies investigated the epidemiological status of Wolbachia at a large scale. In this project, we investigated its infection dynamics in South American termites from whole metagenome sequencing of 2392 termite samples encompassing over 500 species.We reconstructed the termite phylogeny using mitogenomes and nuclear ultraconserved elements (UCEs). Baits targeting a total of 50616 UCEs were specifically designed for termites during this project. UCE-based phylogenies recovered with high support the deep- and shallow-level relationships recovered as yet only by transcriptome-enabled dataset, thereby demonstrating our bait set to be reliable and informative. Dedicated database paper and companion phylogenies were published.Read-mapping approach indicated that 1205 samples were infected by Wolbachia, with two supergroups dominating the South American infection landscape. In a few instances, the majority of samples from single species, with contrasted lifestyles, were infected on their whole range. Hence, such intimate symbioses might explain these species’ ecological success (in prep). These results carve the path to functional genomics and unravelling the true nature of termites-Wolbachia symbioses.