FIG. 6.

FACS analysis demonstrating that UL69 blocks S-phase entry. HF cells were mock infected or infected at a multiplicity of 5 fluorescence units per cell with retro-GFP or retro-UL69. At 24 h after infection, the cells were synchronized in the G₀/G₁ compartment by serum starvation; 48 h later (72 h after infection), the cells were fed with serum-containing medium. To analyze cell cycle progression before and after serum stimulation, the cells were subjected to FACS analysis at 72 h after infection, before serum stimulation (0.2% serum), or at 96 h after infection, i.e., 24 h after serum stimulation (10% serum). The percentage of cells in the G₀/G₁ phase of each infected population was determined. The data shown are from a single experiment representative of two independent experiments with similar results.