Arbovirus minority variants required to traverse bottlenecks in the mosquito

Viral diversity is theorized to play a significant role during arbovirus infections, which must infect vertebrate and invertebrate hosts. To determine how viral diversity influences mosquito infection and dissemination Culex taeniopus mosquitoes were infected with Venezuelan equine encephalitis virus. Bodies, and legs and wings were collected and sequenced. Virus sequence diversity was calculated for each tissue. Differences were seen between mosquitoes with successful dissemination versus those with no dissemination. Diversity across time revealed that bottlenecks influence diversity following dissemination to the legs and wings, but levels of diversity are restored four days post-dissemination. Minority variants were identified in every tissue at every time point, suggesting that certain variants are important in mosquito infection and dissemination. This study demonstrates that the interaction between the mosquito and the virus results in changes in diversity and the mutational spectrum and may be essential for successful transition of the bottlenecks associated with arbovirus infection.