Figure 6.

Gel electrophoresis of BamHI-, KpnI-, PstI-, and SalI-digested vBecker2, vBecker3, PRV253, and PRV-Becker viral nucleocapsid DNA. Restriction fragments unique to vBecker2 are all accounted for by the pBluelox insertion (data not shown). The restriction fragment length polymorphisms observed at ≈3.0 kb and ≈4.0 kb in the BamHI samples (marked by the white asterisks) map to the viral inverted repeats immediately flanking either side of the unique-short region, which contain small direct repeats that fluctuate in copy number during viral replication in mammalian cells (24, 25). Size standards are indicated in kb.