FIG. 5.

Transfected ncp NADLJiv90⁻pac RNA fails to replicate in ncp NADLJiv90⁻ infected cells. Naïve MDBK cells were either mock infected (plates 1 to 4) or acutely infected with ncp NADLJiv90⁻ (plates 5 to 8). The cells were then mock transfected or transfected with in vitro-transcribed ncp NADLJiv90⁻pac RNA. The + and − above each column of plates indicate transfection and mock transfection with ncp NADLJiv90⁻pac RNA, respectively. Following transfection, the cells were incubated in culture medium with and without 5 μg of puromycin per ml as indicated, and viable cells were fixed and stained with crystal violet after 5 days.