Sex influences the mosquito virome in a host-specific way

ABSTRACT Mosquitoes harbor diverse eukaryotic viruses. These viral communities, or viromes, probably influence mosquito physiology, including pathogen transmission. However, the factors shaping the virome remain largely unstudied, limiting our understanding of its role in mosquito biology. Here, we assess the influence of sex on the eukaryotic virome of mosquitoes. Ecological differences between males and females, such as female-specific blood feeding, may lead to differential viral exposure and virome structure. We investigated the influence of sex in sympatric populations of Culex quinquefasciatus and Aedes aegypti, two major human pathogen vectors. A total of 5,743 mosquitoes were collected in various habitats in Burkina Faso (West Africa) over 2 years. Shotgun sequencing of 115 pools revealed 47 viral taxonomic units (VTUs) from 28 viral families. Viromes differed between the two mosquito species, enabling within-species analysis of sex effects. Significant differences in beta diversity were observed between sexes in both species, while alpha diversity differences were significant only in C. quinquefasciatus . Additionally, five indicator viruses, taxonomically diverse and including two novel species, were identified associated with sex. Most indicator VTUs were found in both sexes but with different infection rates. Their low prevalence suggests that sex-based differences are not present in all individuals but are detectable at the population level. Our findings unveil that sex can influence the mosquito virome, and that this effect 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. IMPORTANCE Mosquitoes carry many viruses that do not infect humans but can influence how mosquitoes interact with pathogens that threaten human health. Yet, the factors that shape these viral communities in nature remain poorly understood. Here, we investigated whether male and female mosquitoes differ in the viruses they carry. Sex could affect the virome because males and females have distinct ecological and physiological traits, such as blood feeding in females. We examined the viromes of two major disease vectors, Aedes aegypti and Culex quinquefasciatus , collected in large numbers in Burkina Faso and screened using metagenomics. We found that males and females harbor different viral communities, and that these differences vary between species. These patterns were not driven by sex-specific viruses but by viruses that differed in prevalence between sexes. Our findings show that sex influences mosquito viromes in the field and offer new insight into mosquito–virus interactions.