Fig. 8. Vector flow analysis of monolayers of control and mutant cells in natural aggregation territories. For each strain, a window of several hundred cells was monitored in a monolayer after 6 hours of incubation. In the vector flow plots, the magnitude of the vector components in the selected direction of the aggregation center were averaged and plotted over time for one control strain (nh6b), and mutant strains myoA, myoF and myoA/myoF. Because myoA/myoF cells did not aggregate, an arbitrary direction was selected. The x-axis represents time, and the y-axis the direction and extent of cell displacement. Displacement towards the aggregation center is positive and displacement away from the aggregation is negative. Note that while myoA and myoF cells initiate cyclic surges towards the aggregation center (positive displacement) in a manner similar to control cells, myoA/myoF cells do not initiate cyclic surges in any consistent direction.