Influence of host species and habitat on the mosquito virome

The study of the viral diversity associated to mosquitoes has been mainly focused on viruses affecting human health. However, beyond human viral pathogens, a large diversity of viruses is linked to these insects. The study of this diversity has been largely facilitated with the advent of metagenomics. Consequently, the list of virus species known to be associated to mosquitoes, also known as the virome, has rapidly increased in recent years. Nevertheless, despite this wealth of new data, we are yet far from having identified the mechanisms structuring virome diversity. This knowledge is required to understand how virome diversity is shaped or which virome assemblies can influence the life cycle of mosquitoes and the human pathogens they transmit. Here, we have compared the virome of two mosquito species, Culex tritaeniorhynchus and Culex poicilipes, two vectors of human viral pathogens like Rift Valley fever virus. Populations of the two mosquitoes living in sympatry in three habitats of Northern Senegal were collected along two consecutive years. The three habitats – a river valley, an area near a lake, and a semi-desert area with temporary ponds - differ in water availability and mosquito diversity. Our results show that the two mosquitoes harbored different viromes despite belonging to the same genus and sharing the same habitats. Moreover, habitat influenced virome diversity similarly to mosquito diversity, with lower virus diversity in the habitat with lower water availability. These data are a first step towards our understanding of the forces driving the virus diversity associated to mosquitoes.