FIG 8.

Effects of selection II mutations on viral replication in the presence of the K188-del mutation. (A) IFA of naive BHK-21 cells transfected with genome-length RNA of the WT or mutants (K188-del alone or in combination with various selection II mutations). E-positive cells (green) were stained with MAb 4G2. (B) IFA of NS2A-expressing BHK-21 cells transfected with WT or mutant genome-length RNA. Viral E protein was stained with MAb 4G2 (red). (C) Quantification of PIV_NS2A titers generated from NS2A-expressing BHK-21 cells transfected with the indicated genome-length RNAs. Mean values and standard deviations from the results of three independent experiments are shown. (D) Luciferase replicon analysis. WT or mutant luciferase replicon RNAs containing single or multiple selection II mutations were electroporated into naive BHK-21 cells. Luciferase activities were measured at the indicated time points. NC, negative control using an NS4B lethal mutant, K143A. Each data point shows the average result from three independent experiments, and the error bars represent standard deviations.