Transposon-facilitated recombination in Vibrio cholerae

Auxotrophic mutations induced by Vibrio cholerae mutator phage VcA1

“…These results are similar to those of Zeldis et al [10], who determined the location and orientation of integrated Mu prophages by measuring gene transfer frequencies of comparable Hfr donors. Analogous procedures have been used to determine the sites and orientations of inserted transposons in other Hfr donors [8,9,13].…”

“…The bacteria were derivatives of the prototrophic E1 Tor strain RJ1, which is non-lysogenic and does not contain plasmids [9]. Derivatives included the following strains: RJI (pSJ15) that contains conjugative plasmid pSJ 15 ( 1); R J39 arg-7 ilv-5 thr-1 rif str; RJ44 arg-7 ilv-5 his-2 rif str; RJ47 arg-7 ilv-5 trp-2 rif str; RJ57 arg-7 ilv-5 met-4 thy-3 rif str; and Tfr donor RJ233 [9]. Bacteriophage VcA1 was propagated and titered on strain RJI as previously described [4].…”

“…Donors and recipients were grown and mated in brain heart infusion broth (Difco) using previously described conditions [9,11]. Transconjugants were selected on meat extract agar containing 300 /~g/ml of ampicillin and donors were counterselected with 100/tg/ml of streptomycin.…”

“…Transconjugants were selected on meat extract agar containing 300 /~g/ml of ampicillin and donors were counterselected with 100/tg/ml of streptomycin. Recombinants were selected on supplemented minimal medium A agar [9].…”

“…Plasmid pSJ15 mediated high-frequency polarized chromosomal transfer in strain 162. The Hfr properties were presumed to result from integration of the plasmid into the bacterial chromosome through the homologous dVcA1 sequences contained in both replicons [8,9]. This explanation predicted that similar Hfr-like donors could be constructed by introducing plasmid pSJ 15 in R J1 strains previously lysogenized with phage VcA1.…”