FIG. 4.

Production of infectious virus is reduced for both NLS mutants but more strongly for the NLS2⁻ mutant. Samples collected on days 1 to 8 from HFF cultures infected at an MOI of ∼1 PFU/cell with virus encoding WT UL80 proteins (WT) or the NLS1⁻ or NLS2⁻ UL80 mutants (NLS1⁻ or NLS2⁻) were processed and assayed for infectious virus as described in Results and Materials and Methods. The changing amount of virus present [(number of GFP-expressing foci)(dilution factor) = PFU/ml] in the culture medium each day following infection is shown. Data points and standard deviation bars represent the averages from three replicate samples.