Fig. 7. The effects of the rapid addition of 10^–6 M cAMP. 10^–6 M cAMP was added to a representative control cell (A-C) and representative cells of the myosin II mutants 3XALA (D-F), 3XASP (G-I) and HS1 (J-L). Cells in perfusion chambers were first perfused with buffer alone for 5 minutes and then with buffer containing 10^–6 M cAMP for 4 minutes. See legend to Fig. 2 for color code. Deep purple protrusions on the cell surface represent blebs.