FIG 11.

Growth properties of ORF49-41AAAA44 mutant virus in MeWo and MeWoORF49 cells. (A) Comparison of plaque sizes among recombinant viruses. MeWo cells or MeWoORF49 cells were infected with rpOka, rpOkaORF49-41AAAA44, or rpOkaORF49-41AAAA44Rev (50 PFU/well) and cultured for 7 days. Infected cells were stained with an anti-gE Ab, and the plaques were traced and measured by ImageJ software. Plaque size is shown with the standard error of the mean. Statistical significance was determined by Student's t test. (B) Growth kinetics of recombinant viruses on MeWo cells and MeWoORF49 cells. MeWo cells or MeWoORF49 cells were infected with rpOka, rpOkaORF49-41AAAA44, or rpOkaORF49-41AAAA44Rev (50 PFU/well), harvested at the indicated times, serially diluted, added to newly prepared MeWo cells, and cultured for 5 days. The plaques were stained with an anti-gE Ab and counted. Each point represents the mean titer for two wells of one experiment. Two experiments were performed independently. Statistical significance was determined by Student's t test.