FIG. 3.

Kinetics of UL4 gene expression by wild-type and mutant viruses. Extracts of HF were prepared at various times after infection with the indicated viruses. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gpUL4 (A) and ppUL44 (C) were detected by immunoblot analysis using rabbit anti-gpUL4 serum or a mouse monoclonal antibody, respectively. (B) RNA samples harvested from HF infected at the same time were analyzed by Northern blot hybridization, using probes specific for UL4 or β-actin. Since all the RNA samples were analyzed on one Northern blot for each probe, the mock-infected-cell lane, shown only in the CMV(Towne) panel, is the control for all panels.