Project name: West Nile virus strain:NY99

Description: The emergence of mosquito-borne RNA viruses, such as West Nile virus (WNV), is facilitated by the formation of genetically complex intrahost populations. Mosquito-borne transmission imposes unique evolutionary pressures on WNV: diversification in mosquitoes and selective constraint in birds. We sought to determine whether important enzootic (Culex tarsalis, Cx. quinquefasciatus, and Cx. pipiens) and bridge vectors (Aedes aegypti) of WNV have differential impacts on viral mutational diversity and relative fitness. During systemic mosquito infection, WNV faced stochastic reductions in genetic diversity that was rapidly recovered during intra-tissue population expansions. However, the recovered viral populations contained a preponderance of deleterious mutations (i.e. high mutational load) and had lower relative fitness in avian cells compared to input virus. These findings demonstrate that the adaptive potential associated with mosquito transmission carries a significant fitness cost in vertebrates and that this fitness cost arises during a single systemic infection in a wide array of mosquitoes.

Data type: raw sequence reads

Sample scope: Multiisolate

Relevance: Evolution

Last updated: 2016-02-06