Chikungunya virus adaptation to a mosquito vector correlates with only few point mutations in the viral envelope glycoprotein

Serially- and alternately-passaged strains can be distinguished by amino-acid substitutions in the E2 glycoprotein, responsible for receptor binding. Two substitutions at positions E2-64 and E2-208 only lower the dissemination of the variant E1-226V in Ae. aegypti. These amino-acid changes in the E2 glycoprotein might affect viral infectivity by altering the interaction between CHIKV E1-226V and the cellular receptor on the midgut epithelial cells in Ae. aegypti but not in Aedes albopictus.