Figure 5
Fitness gain of VP3 A116V + VP1 N17D mutant. (a, b) Increase in fitness conferred by VP3 A116V + VP1 N17D replacements both in presence and in absence of NH4Cl. Competition experiments between WT and double mutant VP3 A116V + VP1 N17D during serial passage of a virus mixture, in the absence (a) or in the presence of 25 mM NH4Cl (b). An initial MOI of 0.1 PFU/cell (0.05 PFU/cell for each virus) was used for each infection. Approximate percentage of competing genomes during serial passages was determined by sequencing the capsid coding cDNA. Passage 0 denote the initial mixture of the viruses. Data represent the means ± SDs (n = 3). (c) Rapid fixation of VP1 T22N replacement (nucleotide substitution C3272A) in VP3 A116V + VP1 N17D mutant passaged in presence of 25 mM NH4Cl. The percentage of genomes carrying nucleotide substitution C3272A was calculated in three independent passage series (Experiments 1, 2 and 3).
