Analysing host-shift patterns of Wolbachia strains (Alphaproteobacteria) using comparative genomics
Evolution, Anthropology
Final Report Abstract
Wolbachia bacteria, maternally inherited intracellular Alphaproteobacteria, are highly prevalent among terrestrial arthropods, with up to 52% of species estimated to be infected. They are classified into distinct supergroups, primarily A and B, which manipulate host reproduction for their spread. Vertical transmission is wellunderstood, but horizontal transfer pathways remain unclear. Factors influencing horizontal transmission include host phylogeny, geography, and ecology. Studies suggest infected species from the same ecological community share similar strains. Our research project aimed to analyze horizontal transmission among arthropods, comparing phylogeny, ecology, and biogeography. Sampling focused on arthropod communities associated with four plant species in Germany. A planned comparison in Kentucky, USA, was cancelled due to pandemic travel restrictions. Instead, soil habitat sampling was added locally. By analyzing the presence of Wolbachia in soil arthropods, a lower prevalence compared to above-ground habitats was supported. Moreover, genomic analysis identified a novel Wolbachia supergroup in pseudoscorpions and genome sequencing and phylogenomic analysis revealed high diversity among strains in the soil habitat. Despite uneven success in retrieving genomes from low-coverage data across the sampled arthropod communities, we found evidence for horizontal transmission of biotin operons in bees, suggesting multiple transfer events of functional operons connected to phage regions in the Wolbachia genome. The presence of biotin operons in bees raises questions about their function and evolutionary implications, suggesting potential roles in bee biology yet to be fully understood. Further studies are needed to elucidate these findings.
