TABLE 3.

Results of growth phase experiments with various combinations of tetQ, rteA, and rteB and different concentrations of tetracycline

Element(s) carried by BT4001	Tc concn (μg/ml)	Growth phase effectc
PQ-tetQ-rteA-rteB	1.0	Regulated
PQ-tetQ-rteA-rteB	0	No excision
PQ-tetQ, Pq-rteB*a	1.0	Regulated
PQ-rteB*	0.05	Unregulated
PQ-tetQ, PQ-rteB*	0.05	Unregulated
CTnERL (in BT4104N1-3)b	1.0	Regulated
CTnERL	0.05	Unregulated
PsusA-rteA-rteB (grown on maltose)	0	Unregulated
PsusA-rteA-rteB (grown on glucose)	0	No excision

^arteB* is the activated mutant form of rteB.

^bBT4001 containing CTnERL has been called BT4004 in previous publications.

^c“Regulated” means that there was a growth phase-associated pattern (Fig. 2, panel A), and “Unregulated” means that excision was independent of growth phase (Fig. 2, panel B). Cases in which excision did not occur are indicated by “No excision.”