FIG. 9.

Analysis of IE gene expression from the HSV-1 LAT-null mutant ΔLAP1-2. (A) Northern blot analysis of viral gene expression from wild-type HSV-1 (strain KOS), ΔLAP1-2, and QOZ.HG at different time points following infection of 293T cells. The expression of ICP0, ICP22, and LAT is shown by sequential hybridization of a Northern blot with different probes; 18S rRNA acts as a loading control. (B) Northern blot hybridization analysis of ICP0 and ICP22 mRNA expression in LAT-expressing cell populations, clonal LAT-expressing cell lines, and controls after infection with ΔLAP1-2 at an MOI of 1. There is no evidence that ICP0 mRNA accumulation is suppressed in the presence of LAT in trans, even though the LAT-null deletion was shown to increase ICP0 mRNA expression (A), presumably by acting in cis.