Sex influences the mosquito virome in a host specific way

Background Mosquitoes ( Diptera: Culicidae) harbor a large diversity of eukaryotic viruses. These viral communities, or viromes, probably influence mosquito physiology, including pathogen transmission. However, the factors that structure the virome remain largely unstudied. This lack of data limits our understanding of the influence of the virome on mosquito biology. Here, we assess the influence of sex on the eukaryotic virome of mosquitoes. Differences in the ecology of males and females, like female-specific blood feeding, may lead to differences in exposure to viral diversity. Consequently, mosquito viromes may differ between sexes. Results To explore this hypothesis, we analyzed the influence of sex in sympatric populations of two mosquito species, Culex quinquefasciatus and Aedes aegypti. These mosquitoes are among the most important vectors of human pathogens worldwide. Males and females of both mosquito species were sampled simultaneously in large numbers (5 743 individuals in total) in different habitats in Burkina Faso (West Africa) over a two-year period. A total of 47 viral taxonomic units (VTUs) from 28 viral families were identified in 115 mosquito pools using shotgun sequencing. The viromes differed between the two mosquito species, thus allowing the analysis of sex influence on viromes within each of these species. Significant differences in beta diversity were observed between sexes in both mosquito species. However, significant differences in alpha diversity were only detected in C. quinquefasciatus. Moreover, five indicators viruses were identified associated to sex. Indicator viruses were taxonomically diverse, including two novel species. Contrary to expectations, most of the indicator VTU were found in both sexes but with different infection rates. Their low infection rates suggest that sex-based differences are not present in all individuals and can only be detected at the population level. Conclusions Our findings unveil that sex can influence the mosquito virome, and that this influence depends on mosquito species. Moreover, our results provide a first model of the virome structure as a function of sex in two mosquito species of public health significance.