FIG. 4.

Excision of the BAC vector sequences from reconstituted virus genomes. (A) Structural organization of the viral genomes before and after vector excision. Probe p detects fragments of 11.7 kbp (before vector excision) and 3.1 kbp (after vector excision) in PmlI-digested viral DNA. The duplicated sequences are indicated as hatched boxes. (B) Ethidium bromide-stained agarose gel of PmlI-digested viral DNA isolated from cells transfected with plasmid pSM3fr (first passage) and from cells infected with reconstituted virus after the second to fifth passages. PmlI-digested DNAs of BAC plasmid pSM3fr and MW97.01 virus were used as controls for the presence of the BAC vector-containing fragment and the reconstituted wt genome fragment, respectively. (C) Southern blot analysis of the viral DNAs with probe p.