FIG. 4.

Southern analysis of DNA from keratinocyte cell lines established after transfection of HPV31 or HPV31 genomes containing E2BS mutants. Ten micrograms of total cellular DNA was digested with BamHI (lanes N), which does not cut the HPV31 genome, or with EcoRV (lanes S), which cuts the HPV31 genome once. Genome copy number control lanes representing 50 and 5 copies per cell are shown on the left. Marker sizes are indicated in kilobases to the right. The migration of supercoiled (a), linearized (b), and open circle, concatemeric, or integrated (c) DNA forms is indicated to the right.