FIG. 7.

Virus mutants in which the U exon is mutated have a mild growth defect. (A) The yield of UXP⁻ mutants is slightly lower than the yield of UXP⁺ mutants. HEL299 cells were infected at 10 PFU/cell. At the indicated days p.i., cells and supernatants were harvested. Virus titers were determined by plaque assay on A549 cells. (B) UXP⁻ mutants have slightly smaller plaques that take longer to develop than UXP⁺ mutants. The graph depicts the number of plaques seen during the plaque assay as a percentage of the total number of plaques seen at the end of the assay. Mutants dl7000 and dl7001 form plaques much more slowly than VRX-006 and VRX-021 because the former lack the gene for the adenovirus death protein.