FIG 1.
Generation and characterization of an sfRNA1-deficient WNV. (A) Two-dimensional (2D) RNA structure model of the 3′ UTR/sfRNA of WNVGR. The lines indicate pseudoknot interaction; the nucleotides mutated in WNVΔSF1 are shaded. (B) Northern blot of RNA harvested from Vero cells infected with WNVIC or WNVΔSF1 or mock treated. Numbers at right are kilobases. (C) Vero cells were infected with WNVGR, WNVIC, or WNVΔSF1 at an MOI of 1. Supernatants were taken at 0, 1, 2, 3, and 4 dpi and titrated by EPDA. Shown are the mean titers of two independent experiments ± standard errors of the mean (SEM). Statistics were done using a two-way ANOVA. (D) Vero cells were infected with WNVGR10, WNVIC, or WNVΔSF1 at an MOI of 5, and at the indicated times, the cell viability was measured by CellTiter-Glo assay. hpi, hours postinfection.