FIG. 1.

Mapping SaPIbov by PCR and Southern hybridization. Vectorette PCR was performed on DNA flanking the 6.5-kb HindIII fragment harboring tst and sec. DNA was cleaved with BclI, ligated with the Vectorette cassette, and subjected to PCR with outward-directed primer VL or VR and a primer specific for the Vectorette unit attached to the end of each fragment. These PCR products provided probes A and B, which were used to analyze genomic DNA of strain RF122 tst sec (lanes 1 and 3) and wild-type strain RF120 (lanes 2 and 4). Primers VR and JR1 were used to amplify the 9-kb right junction fragment. The left and right junctions of SaPIbov are denoted by open boxes.