シロアリとその細胞内バクテリアの共生

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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.