FIG 1.

Impact of E2 mutations on the fitness of IOL CHIKV in Aedes albopictus in the absence of E1-226V. Aedes albopictus mosquitoes were fed artificial blood meals with approximately equal genomic ratios of wt and E2 mutant CHIKV SL07, one with an introduced ApaI marker and one without. At 10 dpi, heads were collected, and their virus mixture was passaged for 2 days in Vero cells. The resulting cell culture supernatant was amplified by RT-PCR, and the ratio of ApaI-marked to unmarked CHIKV was determined by restriction digestion. Reciprocal experiments were conducted such that the ApaI marker was present in either the mutant (A) or the wt (B) strain. Relative replicative fitness values were calculated as described in Materials and Methods. The Holm-Sidak correction for multiple P values was applied. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.