FIG 4 .

CHIKV replication at target sites in vivo is not impaired by mutagenesis of the opal stop codon. Twenty-four-day-old C57BL/6J mice were infected in the left rear footpad with 100 PFU of wild-type CHIKV or the Opal524R mutant (9 to 10 mice per group per time point). Mice were sacrificed at 1 (A), 3 (B), 5 (C), or 7 (D) days postinfection, and the indicated tissues were harvested. Tissues were homogenized and titers were determined by plaque assay on Vero cells. Horizontal bars represent the arithmetic mean. Dashed horizontal lines represent the limit of detection for the assay. LF, left (ipsilateral) foot; LQ, left quadriceps muscle; RF, right (contralateral) foot; RQ, right quadriceps muscle; LN, popliteal lymph node. Combined data from two independent experiments are shown. Data were analyzed by one-way ANOVA for significance, with corrections for multiple comparisons. Statistical significance is indicated as follows: *, P < 0.05.