FIG. 4.

RT-nested-PCR analysis of HPV31b spliced E2 transcripts expressed following infection of HaCaT cells. Details of the experiment are given in the legend to Fig. 3. (A) Primers E6A and E2.2B were used in the first round, and primers E6.2A and E1B were used in nested PCR. (B) Primers E7.4A and E2.2B were used in the first round, and primers 742A and E1B were used in nested PCR. For each reaction, the input RNA in the first round of PCR corresponded to 1.9 μg. (C) Early region of the HPV31b genome and explanation of observed RNA structures as described in the legend to Fig. 1 and 3C. Boldface letters denote previously characterized ORFs, with their splice junctions indicated in parentheses. The novel RNA structures containing the 877∧2513 splice junction, the 210∧2513 splice junction, and the 210∧2646 splice junction are indicated. Each of the novel spliced structures was verified by sequencing from at least one of the samples as shown.