Résumé
The microbial community composition is crucial for diverse life-history
traits in many organisms. However, we still lack
a sufficient understanding of how the host microbiome is
acquired and maintained, a pressing issue in times of global environmental
change. Here we investigated to what extent host genotype, environmental
conditions, and the endosymbiont Wolbachia influence the
bacterial communities in the parasitic wasp Asobara japonica. We
sampled multiple wasp populations across ten locations
in their natural distribution range in Japan and sequenced the host genome
(whole genome sequencing) and microbiome (16S rRNA gene). We compared the
host population structure and bacterial community composition of wasps
that reproduce sexually and are uninfected
with Wolbachia with wasps that reproduce asexually and
carry Wolbachia. The bacterial communities in asexual wasps were
highly similar due to a strong effect
of Wolbachia rather than host genomic structure. In
contrast, in sexual wasps, bacterial communities appear primarily shaped
by a combination of population structure and environmental conditions. Our
research highlights that multiple factors shape the bacterial communities
of an organism and that the presence of a single endosymbiont can strongly
alter their compositions. This information is crucial to understanding how
organisms and their associated microbiome will react in the face of
environmental change.