TABLE 3.

2D-DIAS analysis of chemotaxis in a spatial gradient of cAMP^a

Parameter	Value for strain			Pb
	JH10	acaA−	acaA− (r)	acaA− vs JH10	acaA− (r) vs JH10
Motility and chemotaxis parameters
No. of cells	20	26	16
Instantaneous velocity (μm/min)	11.2 ± 3.9	6.8 ± 3.0	6.8 ± 1.8	2.3 × 10−4	1.5 × 10−4
Directional persistence	0.82 ± 0.14	0.44 ± 0.21	0.31 ± 0.16	3.0 × 10−9	3.6 × 10−11
Directional change (°/4 s)	16 ± 5	30 ± 10	46 ± 9	1.5 × 10−7	2.6 × 10−11
Chemotactic index	+0.80 ± 0.18	+0.15 ± 0.35	+0.11 ± 0.30	2.1 × 10−13	2.3 × 10−13
Percent positive chemotaxis	100	65	63	5.8 × 10−10	3.1 × 10−8
Shape parameters
No. of cells	20	26	16
Maximum width (μm)	6.2 ± 0.8	9.9 ± 1.6	9.9 ± 2.7	9.1 × 10−13	6.4 × 10−5
Maximum length (μm)	22.3 ± 5.0	17.8 ± 3.7	16.1 ± 3.3	1.8 × 10−3	8.0 × 10−5
Roundness (%)	45 ± 9	63 ± 11	66 ± 7	1.3 × 10−7	4.5 × 10−9
Radial deviation (%)	43 ± 5	28 ± 5	26 ± 4	2.1 × 10−13	2.3 × 10−13

^aParameters (means ± standard deviations) are calculated according to the method of Soll (30).

^bP values of ≥0.05 were considered nonsignificant.