FIG. 7.

Rescue of mutant viruses. The rescue of viruses containing deletions or alanine substitutions in the CT domains was attempted as described in Materials and Methods. Recombinant viruses were obtained from transfections involving BUNMGcCTA1 and BUNMGcA4 DNAs. (A) Yields of transfectant viruses rBUNGcCTA1 and rBUNGcA4. Supernatants from the initial transfection dishes were titrated by plaque assay on Vero cells. The results are the averages for two independent titrations. (B) Comparison of plaque sizes produced on Vero cells. The right column represents typical images of single plaques under a light microscope (magnification, ×100). Cell monolayers were fixed with 4% formaldehyde-PBS and stained with Giemsa solution.