FIG 4.

Infectivity of the rSA11-s11KU-delNSP6 monoreassortant virus lacking NSP6 expression. (A) Single-step growth curves of rSA11-s11KU and rSA11-s11KU-delNSP6. MA104 cells were infected with rSA11-s11KU or rSA11-s11KU-delNSP6 at an MOI of 5 and then incubated for various times. Virus titers in the cultures were determined by plaque assay. The data shown are the mean viral titers and SDs for three independent cell cultures. (B) Plaque formation by rSA11-s11KU and rSA11-s11KU-delNSP6. rSA11-s11KU or rSA11-s11KU-delNSP6 was directly plated onto CV-1 cells for plaque formation. The experiment was repeated three times with similar results, and representative results are shown.