. 2006 Dec 15;189(5):1556–1564. doi: 10.1128/JB.01580-06

TABLE 4.

Flagellar-phase transition rates are differentially affected in Dam^OP derivatives of strains 14028 and LT2

Strain^a	Genotype	Switching frequency (10⁻³)		fljB_On to fljB_Off/fljB_Off to fljB_On
Strain^a	Genotype	fljB_On to fljB_Off	fljB_Off to fljB_On	fljB_On to fljB_Off/fljB_Off to fljB_On
14028	dam⁺	1.69	0.446	3.8
	dam mutant	2.79	0.820	3.4
	Dam^OP	1.90	0.238	8.0
LT2	dam⁺	1.19	0.469	2.5
	dam mutant	2.23	0.463	4.8
	Dam^OP	1.65	1.26	1.3

fljB::lacZ transition rates (per cell per generation) of fljB_On to fljB_Off and fljB_Off to fljB_On were calculated from a single blue colony (Lac⁺) or a single white colony (Lac⁻) from dam⁺, dam mutant, and Dam^OP derivatives of fljB5001::MudJ fusions (38) in Typhimurium pathogenic strain, 14028, and avirulent laboratory strain, LT2, grown on minimal E medium agar (25) containing 0.2% glycerol and 40 to 80 μg of X-Gal/ml. Colonies exhibiting a Lac⁺ or Lac⁻ phenotype (no sectors) were excised from the agar and plated to determine the total number of organisms in the colony and to score the Lac phenotype after incubation for 48 h at 37°C. Transition rates represent the weighted average of five independent colonies as described in Materials and Methods.