Relative Contributions of Genetic and Non-Genetic Factors on Mosquito Microbiota

Abstract Background The commensal microbiota of mosquitoes impacts their development, immunity, and competency, and could provide a target for alternative entomological control approaches. However, despite the importance of the mosquito/microbiota interactions, little is known about the relative contribution of genetic and non-genetic factors in shaping the bacterial communities of mosquitoes. Methods We used a high-throughput sequencing based assay to characterize the bacterial composition and diversity of 665 individual field-caught mosquitoes, as well as their species, genotype at an insecticide resistance locus, blood meal composition, and the eukaryotic parasites and viruses they carry. We then used these data to rigorously estimate the individual effect of each parameter on the bacterial diversity as well as their relative contribution to the microbial composition. Results Overall, multivariate analyses did not reveal any significant contribution of the mosquito species, insecticide resistance or blood meal to the bacterial composition of the mosquitoes surveyed. Infection with parasites and viruses only contributed very marginally and the main driver of the bacterial diversity was the location where each mosquito was collected which explained roughly 20% of the variance observed. Conclusions This analysis shows that, when confounding factors are taken into account, the sites where the mosquitoes are collected is the main driver of the bacterial diversity of wild-caught mosquitoes, although further studies will be needed to determine how the specific components of the local environment affecting the bacterial composition.