The roles of host evolutionary relationships (genus: Nasonia) and development in structuring microbial communities

The comparative structure of bacterial communities among closely related host species remains relatively unexplored. For instance, as speciation events progress from incipient to complete stages, does divergence in the composition of the species' microbial communities parallel the divergence of host nuclear genes? To address this question, we used the recently diverged species of the parasitoid wasp genus Nasoniato test whether the evolutionary relationships of their bacterial microbiotas recapitulate theNasoniaphylogenetic history. We also assessed microbial diversity inNasoniaat different stages of development to determine the role that host age plays in microbiota structure. The results indicate that all three species ofNasoniashare simple larval microbiotas dominated by the γ-proteobacteria class; however, bacterial species diversity increases asNasoniadevelop into pupae and adults. Finally, under identical environmental conditions, the relationships of the microbial communities reflect the phylogeny of theNasoniahost species at multiple developmental stages, which suggests that the structure of an animal's microbial community is closely allied with divergence of host genes. These findings highlight the importance of host evolutionary relationships on microbiota composition and have broad implications for future studies of microbial symbiosis and animal speciation.