Mutagenizing position 483 variants allows isolation of mutator variants.

<p>(A) HeLa cells, treated with 200 µM or 400 µM ribavirin, or left untreated, were infected at an MOI of 0.1. The percentage of infectious progeny virus surviving treatment at both concentrations of ribavirin relative to the untreated control is shown (mean values ± SEM, n = 3, *P at least<0.05, two-way ANOVA with Bonferroni posttest). ND, not determined. (B) Average mutation frequencies of WT CHIKV and variants with significantly altered fidelity. Mutation frequency is shown as the mean number of mutations per 10,000 nucleotides sequenced by molecular cloning. Variants 483A, G and W made significantly more errors than WT virus (*P<0.05, **P<0.01, ***P<0.001, χ² test). (C) Average diversity of confirmed fidelity variants at each position across the genome. The root-mean-square-deviation (RMSD) is shown (mean values ± SEM, ***P<0.001, Mann-Whitney <i>u</i> test). (D) Neutralization assay showing enhanced escape of mutators due to greater population diversity (mean values ± SEM, *P<0.05, **P<0.01, ***P<0.001, two-way ANOVA with Bonferroni posttest).