Fig. 4.

Calcium regulates the propagation of directionality waves. a Extracellular Ca²⁺ significantly affects directionality and speed for cell migration. Kymographs show that Ca²⁺ had different effects on directionality wave propagation and speed. b High Ca²⁺ did not affect migration speed. The graph shows the time course of the proportion of cells in the sheet reaching a speed >40 µm/h for control, EGTA 2 mM, calcium 120 µM groups. c High extracellular Ca²⁺ increased, while depletion of Ca²⁺ decreased, the rate of directionality wave propagation. *p < 0.05, **p < 0.01 when compared with the control value using a Student’s t test. Data of the proportion of cells reaching a certain threshold over time are mean ± SEM from three independent experiments. Data on wave propagation rates are mean ± SEM from four independent wounds