Mutation of PRV R2 results in a post-entry microtubule-dependent delay in gene expression.

(A) Percent of PRV internalized into PK15 epithelial cells prior to extracellular virion inactivation with citrate at indicated times post-infection. Five experimental replicates are shown for each virus, with each representing average values from duplicate infections. (B) Expression of the PRV immediate early gene IE180 was quantified by qRT-PCR and normalized to expression of the host S28 rRNA at 4 hpi with the wild-type (WT) and R2 mutant (R2). Where indicated, 9 μM of nocodazole was added 1 hr prior to infection and maintained throughout the infection. All values were plotted relative to levels observed during the untreated wild-type (WT) infection. Three independent experiments were performed with each experimental replicate performed in triplicate. Values are expressed as mean ± s.e.m. (****, p < 0.0001; ns, not significant based on two-tailed unpaired t test).