Figure 6.

F-actin organization in blebbistatin-treated cells. BAECs migrating at a wound edge for 1 h in the absence (A–C) or presence (D–F) of 100 μM blebbistatin were double-stained with for F-actin (A and D) and myosin IIA (B and E). Color overlays of F-actin in green and myosin IIA in red are shown in C and F. White arrows in A and D indicate the direction of cell spreading, with the nucleus of the cell located on the right-hand side of the lower edge of the image in both cases. Note the numerous, long, F-actin bundles lying perpendicular to the direction of movement in untreated cells. Myosin IIA is organized in periodic stripes across these bundles. In 100 μM blebbistatin, F-actin-rich “ruffles” (D, black arrows) project from the dorsal surface just behind the leading edge. F-actin bundles are short and isotropic and lack myosin IIA striation.