FIG. 7.

Kinetics of NS mRNAs in transfected cells. (A) COS-1 cells were transfected with either pME18S-WTNS (WTNS lanes) or pME18S-L20,45stop (L20,45stop lanes) in which a premature termination of translation was introduced into the Leu residues at positions 20 and 45 of the influenza C virus NS coding region. The unspliced and spliced NS mRNAs at the indicated times posttransfection were quantitated by RNase protection assay using a ³³P-labeled influenza C virus RNA segment 7 (NS gene)-specific RNA probe (vRNA sense). The probe lane contains the undigested probe. (B) Ratios of 3′ spliced NS mRNA to unspliced NS mRNA in cells transfected with pME18S-WTNS (open circles) or pME18S-L20,45stop (closed circles).