Figure 6

LSM simulations of cell shape changes during chemotaxis. A. We simulated the change in cellular morphology of a Dictyostelium cell exposed to a point source of chemoattractant (1 μ M of cAMP). Shown is the resultant chemoattractant field (computed by solving the diffusion equation) as well as the location of the cell at times 0, 1.5, 10, 40, 60, 80 and 100 s. Initially, the cell is assumed to be round (red circle). B. In this model, pressure was determined by the concentration of PI(3,4,5)P₃ on the membrane as described in the text. The maximum and minimum refer to the concentrations experienced by the cell around the membrane. C. The position of the cell (blue) was plotted as a function of time, showing fairly constant velocity (11.7 μ m/min). Also shown is the cell's area (red) during the simulation demonstrating that changes are also minimal.