FIG. 4.
Analysis of mutations responsible for 3′UAR-PPMO resistance. The plaque morphologies, 5′UAR/3′UAR base-pairings, and 3′UAR-PPMO resistance are shown for WT WNV (A), four recombinant viruses (B–E), and Sel I P8 virus (F). For resistance analysis, Vero cells were infected with the indicated virus at an MOI of 0.1 with or without 20 μM of 3′UAR-PPMO. Viral titers in culture fluids were measured by plaque assays at indicated time points post-infection. Mean values from three independent experiments are presented. Error bars represent standard deviations.