TABLE 3.

Frequencies of Mu and Lac+ transfers during conjugation with SM10 λpir and S17-1 λpir donor strain derivatives

Donor [relevant characteristics] (plasmid)aRecipientTransconjugant frequencyb% Mu transferc% Lac+c
S17-1 λpir [ChRP4 pir+] (pSC189)MG1655 Δlac1.7 × 10−2 ± 5.5 × 10−363 ± 130.014 ± 0.009
S17-1 λpir [ChRP4 pir+] (pSC189) with 10 mM sodium citrateMG1655 Δlac with 10 mM sodium citrate3.4 × 10−3 ± 1.8 × 10−335 ± 34NDd
S17-1 λpir [ChRP4 pir+]MG1655 ΔlacND61 ± 17e0.55 ± 0.37e
SM10 λpir [ChRP4 pir+] (pSC189-Cm)MG1655-s Δlac6.3 × 10−2 ± 5.4 × 10−289 ± 10<0.001
ω7249 [ChRP4Δnicpir+] (pSC189-Cm)MG1655-s Δlac1.2 × 10−3 ± 3.2 × 10−493 ± 3<0.001
MFDpir [ChRP4 Δnic ΔMu pir+] (pSC189-Cm)MG1655-s Δlac2.0 × 10−3 ± 1.0 × 10−3<0.72<0.001
  • a ChRP4, chromosomal integration of RP4-2-Tc::Mu.

  • b Expressed as the mean number ± standard deviation of transconjugants per recipient cell.

  • c Expressed as the percentage ± standard deviation of events in the transconjugant population. The percentage of Mu transfer was determined by PCR on 46 colonies per mating. The percentage of Lac+ colonies was determined by plating on X-Gal-containing agar plates. Three independent matings were done for each condition.

  • d ND, not determined.

  • e Expressed as the percentage ± standard deviation of events in the exconjugant recipient population.