In vivo phenotypes of mutants expressing extra copies of ICP0 and VP16.

<p>A) Viral replication in trigeminal ganglia (TG). Outbred Swiss Webster mice were infected via both corneas with 1x10⁵ pfu of the indicated virus isolates. Tissues from three mice per viral mutant per time point were harvested and analyzed for infectious virus titers. Bars represent the fold increase in titer relative to the parental strain 17syn+. Viral titers appear in the text. B) Survival was determined in groups of mice infected on the eyes with 1x10⁵ pfu. The color code is the same as that in Fig 2A with the addition of a gray colored line which represents mice infected with the wild type strain McKrae (a virulent laboratory strain). C) Replication and spread of virus within the central nervous system was assessed by examining virus titers in four roughly equal divisions as depicted below the graphs. Viral titers detected on days 5, 7 and 9 pi in the CNS of three mice from each group are shown. 17LATpVP16R is a genomically restored isolate in which the VP16 transgene in the 17LATpVP16 mutant was removed (detailed in methods). Each bar represents the average of the amount of virus found in each of the brain sections. There was no significant difference between 17syn+ and 17LATpVP16R infected brain regions (bar labeled NS for not significant). There was significantly more virus detected in all four brain sections infected with 17LATpVP16 compared to 17syn+ and 17LATpVP16R (bar labeled ** is p<0.05; labeled *** is p<0.001). Both Fisher’s exact test and unpaired Student’s t-test were employed.