FIG. 3.

Southern hybridization showing true transposition of DEH-ISPpu12 from pAWT34 into the chromosome of P. putida PaW340. Ten independent transposition transconjugants were selected on 2MCPA-SBS medium from 6-h filter matings between the donor E. coli S17-1(pAWT34) and recipient PaW340. (A) Genomic DNAs from strains PaW340 T1 to T10 digested with XhoI (lanes 1 to 10, respectively) and EcoRI (lanes 11 to 20, respectively), blotted, and hybridized with the DIG-labeled dehI-dehR_I probe (Fig. 1). Lane 21, control DNA from strain PaW340 digested with EcoRI. (B) Replicate Southern blot hybridized with the ISPpu12 probe (Fig. 1). Circles are placed alongside XhoI DNA fragments hybridizing only with DIG-labeled ISPpu12, indicating transposition of this element independently of DEH. All strains were Tc^s, and none hybridized with the pSUP202 vector probe (results not shown).