Chemotactic behavior in a spatial cAMP gradient
. | AX2 . | gefQ− . |
|---|---|---|
| Buffer | ||
| Speed (μm/min) | 6.04 ± 3.14 | 5.47 ± 1.41 |
| Persistence (μm/min-degree) | 1.35 ± 0.88 | 1.4 ± 0.78 |
| Directionality | 0.31 ± 0.18 | 0.34 ± 0.14 |
| Direction change (degree) | 50.9 ± 12.84 | 50.12 ± 11.74 |
| cAMP gradient | ||
| Speed (μm/min) | 10.62 ± 2.23 | 12.21 ± 3.01 |
| Persistence (μm/min-degree) | 3.76 ± 1.06 | 4.47 ± 1.28 |
| Directionality | 0.79 ± 0.12 | 0.79 ± 0.12 |
| Direction change (degree) | 21.63 ± 12 | 18.66 ± 7.16 |
. | AX2 . | gefQ− . |
|---|---|---|
| Buffer | ||
| Speed (μm/min) | 6.04 ± 3.14 | 5.47 ± 1.41 |
| Persistence (μm/min-degree) | 1.35 ± 0.88 | 1.4 ± 0.78 |
| Directionality | 0.31 ± 0.18 | 0.34 ± 0.14 |
| Direction change (degree) | 50.9 ± 12.84 | 50.12 ± 11.74 |
| cAMP gradient | ||
| Speed (μm/min) | 10.62 ± 2.23 | 12.21 ± 3.01 |
| Persistence (μm/min-degree) | 3.76 ± 1.06 | 4.47 ± 1.28 |
| Directionality | 0.79 ± 0.12 | 0.79 ± 0.12 |
| Direction change (degree) | 21.63 ± 12 | 18.66 ± 7.16 |
Images were taken at magnification of 20× every 30 s. In all cases, cells were analyzed for at least 10 min. The DIAS software was used to trace individual cells along the image series and calculate motility parameters. Persistence is an estimation of movement in the direction of the path. Directionality is calculated as the net path length divided by the total path length and gives a value of 1 for a straight path. Directional change represents the average change of angle between frames in the direction of movement. Values are mean standard deviation of 30–90 cells from at least three independent experiments. For both strains, all parameters varied significantly between the buffer and cAMP conditions