Table 2. An excess of wild-type donor cells reduces the transfer frequency from up-mutant donors.
| Gene disrupted by mariner/Kmr | Tenfold excess of MKD158 | Average transfer frequency, no. of Kmr Smr transconjugants per donor | Fold decrease in transfer with addition of MKD158 |
|---|---|---|---|
| Wild-type MKD10 | 1.43 ± 0.6 × 10-5 | ||
| MKD10 | + | 1.26 ± 0.16 × 10-5 | 1.14 |
| Ms3868 | 3.17 ± 4.2 × 10-3 | ||
| Ms3868 | + | 3.1 ± 1.8 × 10-5 | 102 |
| Ms3869 | 6 ± 5.5 × 10-3 | ||
| Ms3869 | + | 6.2 ± 2.3 × 10-5 | 97 |
| Ms3871 | 3.01 ± 1.6 × 10-3 | ||
| Ms3871 | + | 3.44 ± 0.97 × 10-5 | 88 |
| Mscfp-10 | 2.00 ± 0.71 × 10-4 | ||
| Mscfp-10 | + | 4.35 ± 1.3 × 10-6 | 46 |
Transfer of the Kmr marker was measured into the Smr recipient MKD8. Transfer is expressed as Kmr Smr transconjugants per donor and is expressed as the average of five experiments. In control experiments, we showed that transfer of Hygr from MKD158 was unaffected. Matings were carried out for 18 h at 30°C. Note that transfer frequencies and ratios differ slightly from those in Fig. 3, because we are monitoring transfer of Kmr from within the RD1 locus and comparing it with transfer of a wild-type Kmr donor rather than comparison with transfer of Hygr from the attB site. Thus, although the absolute frequencies vary between Fig. 3 and this table, the reduction in transfer caused by excess wild-type donor is clear and reproducible.