FIG. 9.

Nuclear run-on transcription analysis of viral gene transcription in d13-lacZ-infected HEL cells. HEL cells were infected with the WT virus strain KOS1.1 (A), the ICP22 mutant 22/n199 (B), or the UL13 mutant d13-lacZ (C) for the times indicated. Nuclei were isolated, and transcription was allowed to proceed in the presence of [³²P]UTP as described in Materials and Methods. RNA products from equal numbers of nuclei per sample were hybridized to immobilized single-stranded DNA probes which detect sense (S) or antisense (AS) transcripts arising from the IE genes ICP4 and ICP27 and the L genes ICP5, VP16 (ICP25), and UL36 (ICP1-2). Single-stranded DNA of M13mp19 was included as a background hybridization control. Nuclear run-on transcription assays of mock-infected cells yielded no hybridization to these probes (data not shown). (D) Quantitation of the relative ³²P-labeled hybridization signals to the ICP5, VP16, and UL36 gene probes by phosphorimager analysis at 9 h p.i. The values shown are in arbitrary units. Sense transcription levels are denoted by solid bars; antisense transcription levels are indicated by crosshatched bars.