Translocation of the cell body depends on leading edge protrusion in blebbistatin-treated cells. (A and B) Treatment of the cell with cytochalasin D results in the arrest of the leading edge while the cell body continues to move (Video 4, left). (C and D) Treatment with cytochalasin D of the cell pretreated with blebbistatin results in the simultaneous arrest of the leading edge and the cell body (Video 4, right). (A and C) Time-lapse sequences of phase-contrast images; experiment on a clear glass substrate is shown for clarity, but similar results were obtained on elastic gelatin substrate. Blue and red lines and arrows indicate the positions and displacements of the leading edge and the front margin of the cell body, respectively; time after the addition of cytochalasin D is indicated in the images. (B and D) Displacement in time of the leading edge (blue) and of the front margin of the cell body (red). The time of cytochalasin D addition is indicated by black arrows, and blue arrows indicate the time when the front of the cell stopped. Stress dynamics during comparable cytochalasin D treatment are shown in Fig. 4 (A–C). Stress dynamics during combined blebbistatin and cytochalasin D treatment were not reliably measurable because of the low level of deformation. Bar, 10 µm.