FIG 4.

Characterization of DAR mutants using the ZIKV infectious clone. (A) IFA analysis of viral protein expression in mutant-RNA-transfected Vero and C6/36 cells. Equal amounts of the in vitro-transcribed RNAs were transfected into Vero and C6/36 cells, and IFA was performed at 48 and 72 hpt in Vero cells and at 96 and 168 hpt in C6/36 cells. (B and C) Viral production of supernatants from mutant-RNA-transfected Vero (B) and C6/36 (C) cells. The supernatants harvested from the two cell types at the indicated time points were subjected to plaque assays to determine viral titers. (D and E) Growth curves of mutant viruses in Vero (D) and C6/36 (E) cells. The mutant viruses collected from Vero cells at 72 hpt were used to infect naive Vero and C6/36 cells at an MOI of 0.1, and the virus titers at the indicated time points after infection were determined by plaque assay. ND, not detectable. The data are representative of three independent experiments. Each experiment was performed in triplicate, and the error bars represent standard deviations.