TABLE 2.
Quantitation of LacZ expression of isolates with agn′-lacZ fusions containing deletions of the regulatory region as shown in Fig. 4
| Strain | Colony phenotypea | Relevant genotypeb | Mean ± SDc β-galactosidase activity (MU) | % Lac+d |
|---|---|---|---|---|
| MV348 | agn(9296-9525)′-lacZ | 4 | NAd | |
| MV356 | MV348 dam-13::Tn9 | 6 | NA | |
| MV357 | MV348 oxyR::Ω(Spec) | 3 | NA | |
| MV358 | MV348 pTP166 | 2 | NA | |
| MV365 | agn(9248-9525)′-lacZ | 6 | NA | |
| MV367 | MV365 dam-13::Tn9 | 4 | NA | |
| MV366 | MV365 oxyR::Ω(Spec) | 6 | NA | |
| MV368 | MV365 pTP166 | 19 ± 1 | NA | |
| MV301 | Lac+ | agn(9212-9525)′-lacZ | 656 ± 22 | 74 |
| Lac− | 25 ± 1 | 7 | ||
| MV311 | MV301 dam-13::Tn9 | 10 ± 1 | NA | |
| MV317 | MV301 oxyR::Ω(Spec) | 1,039 ± 62 | NA | |
| MV312 | MV301 pTpP166 | 795 ± 79 | NA | |
| MV500 | Lac+ | agn(8785-9312)′-lacZ | 86 ± 3 | 92 |
| Lac− | 15 ± 1 | 18 | ||
| MV501 | MV500 dam-13::Tn9 | 7 ± 3 | NA | |
| MV502 | MV500 oxyR::Ω(Spec) | 81 ± 8 | NA | |
| MV505 | MV500 pTP166 | 138 ± 6 | NA | |
| MV556 | Lac+ | agn(9212-9312)′-lacZ | 43 ± 3 | 95 |
| Lac− | 7 | 13 | ||
| MV557 | MV556 pTP166 | 68 ± 4 | NA | |
| MV201 | MV198 oxyR::Ω(Spec) | 1,312 ± 100 | NA | |
| MV203 | MV198 pTP166 | 906 ± 88 | NA |
a
Cultures of phase-varying isolates were started with a Lac+ or Lac− colony as indicated.
b
Isolates containing pTP166 have an increased level of Dam activity.
c
SD was less than 1 MU if no value for the SD is given.
d
The percentage of Lac+ cells at the time of the assay. NA, not applicable; colonies have uniform Lac phenotype.