Table 2.

The mutants deficient in tra gene induction are altered in their ability to transfer pTiC58ΔaccR

StrainRelative level of expression of reportersaConjugal transfer frequencyb
NT1++++2.7 × 10−2
NTM4+/−<10−8
NTM5+/−<10−8
NTM6++3.5 × 10−6
NTM7+/−<10−8
  • a Assessed on ABM medium containing X-Gal after 2 days of incubation. Each strain harbored the two reporter plasmids pDCKI41 and pRKL17. ++++, intensely blue colonies; ++, medium-blue colonies; +/−, very pale blue colonies.

  • b Conjugal transfer of pTiC58ΔaccRfrom the parent and the four mutants to C58C1RS was tested as described in Materials and Methods. The frequency of transfer is expressed as the number of transconjugants obtained per input donor.