FIG. 5.
Recombinant BDV expressing P-AASS or P-DDSS is attenuated in cell culture. C6 (A), Vero (B), and Oligo (C) cells were simultaneously infected with the indicated BDV strains using 1,000 focus-forming units. The number of infected cells was determined by immunofluorescence using an N-specific antiserum.