Fig. 3. Submarginal membrane protrusions form shortly after wounding and display typical lamellipodial morphology and dynamics. Panels from a time-lapse sequence (see supplementary material, Movie 2) of a basal focal plane of a wounded MDCK cell monolayer (1:10 ratio of GFP-actin-expressing:nontransfected cells) immediately after wounding to 4 hours post-wounding, imaged by two-photon microscopy. The initial width of the rectangular wounds was 700 µm. The visible GFP-actin-expressing submarginal cells are 4-5 cells rows from the wound margin. The dark area to the right of the visible cells is composed of nontransfected submarginal cells. The wound margin is located outside of the images to the right in the direction of the arrow.