FIG. 1.

Expression of plasmid-encoded RNAs in tissue culture. (A) The β-galactosidase gene of the parental vector was replaced by sequences specific for the capsid proteins VP1 (851 bp), VP3 and VP1 (1,565 bp), VP4 and VP2 (995 bp), and VP4 to VP1 (2,561 bp) of CVB3. (B) Transcriptional activities of the plasmids pCMV/VP1, pCMV/VP3-1, pCMV/VP4-2, and pCMV/VP4-1 were analyzed by transient transfection of HeLa cells followed by RNA isolation, DNase treatment, cDNA synthesis, and PCR using the original primer pairs. No PCR product was detectable in pCMV-transfected cultures, demonstrating the specificity of the PCR conditions. In addition, the presence of VP1 in a protein extract of pCMV/VP1-transfected HeLa cells was analyzed (last lane) by Western blot analysis.