Fig. 2.

Single-step growth and plaque formation on Vero, WT pUL34-expressing, or Y68A mutant pUL34-expressing cell lines. For single-step growth replicate, cultures of Vero cells, WT UL34-express-ing cells, or Y68A UL34-expressing cells were infected at an MOI of 5 with HSV-1(F) (A), the UL34-null virus vRR1072(TK+) (E), or Y68ARev (I). Residual virus was removed or inactivated with a low-pH wash, and at the indicated times total culture virus was titrated on WT UL34-expressing cells. Virus yields are expressed as PFU per milliliter. Each data point represents the mean of results from three independent experiments. Error bars indicate the range of values. For plaque formation assays, digital micrographs of infected cell monolayers stained for glycoprotein D are shown. The cell line infected is indicated to the left of each panel. In panels B to D, the infecting virus was HSV-1(F). In panels F to H, the infecting virus was the UL34-null virus vRR1072(TK+). In panels J to L, the infecting virus was Y68ARev. All plaques were fixed and stained at 2 days after infection. All plaque images are shown at the same magnification.