Fig. 7. mDia2 is necessary for concerted leading edge protrusions and retractions and rapid cell migration. (A) Control and mDia2 antibody-injected (anti-mDia2) cells were microinjected with X-Rhodamine actin and filmed by time-lapse spinning-disk confocal microscopy. Using qFSM software, the position of the cell edge was extracted from each image and are shown as changing from warm to cool colors over time. The edge of control cells are smooth and protrude and adjacent regions retract in a concerted fashion, whereas mDia2 antibody-injected cells displayed a much more ragged cell edge. (B) Kymographs taken from phase-contrast time-lapse images used to measure parameters of leading-edge dynamics. (C) The distance, rate and frequency of protrusions and retractions were not affected by mDia2 inhibition; n=10 cells per treatment, three measurements per cell. (D) The rate of PtK1 cell migration was significantly reduced by mDia2 inhibition, n=30 cells per treatment.