Growth properties of PrV-gH I662S and PrV-gH I662S/ΔgL. (A) RK13 cells were infected with the indicated mutants at a MOI of 0.5. Cells and supernatant were harvested at 24 h and 48 h post infection, and titers were determined on RK13 cells. Mean titers and corresponding standard deviations of three independent experiments are shown. (B) RK13 were infected with the indicated virus mutants under plaque assay conditions and plaque diameters were measured two days post infection. Shown are mean percent values (compared to PrV-ΔgGgfp plaques) and corresponding standard deviations from three different experiments. Two-tailed Welch’s t test; ns, not significant; *, p < 0.05; **, p < 0.01; ****, p < 0.0001. (C) Representative images of plaques formed by the indicated virus mutants one day post infection are shown. Scale bar: 100 µm.