FIG. 5.

Primer extension analysis on the negative-sense RNAs generated in transfections of 3′CB replicons that contained inserted Tr sequences. (A) Polyacrylamide gel analysis of the primer extension products obtained from total cytoplasmic RNAs extracted from BHK-21 cells that were transfected 23 h earlier with cDNAs of either the 3′CB, 3′CB/Tr, 3′CB/TrC, or WT replicon together with the VSV N and P support plasmids in the presence (+Pol) or absence (−Pol) of the L support plasmid. The oligonucleotide primer (large arrow) annealed to negative-sense RNA at residues 10925 to 10908 of the complete VSV genome sequence. The schematic of the genome of 3′CB/Tr depicts the positions at which the polymerase-dependent products map. (B) Primer extension analysis of the products of replication from WT and 3′CB/Tr in the infectivity assay. A sequence ladder of 3′CB/TrC sequenced with the same primer is shown for reference.