Figure 5.

Y-27632 inhibits contraction but not formation of the actin ring. A, A control E18 utricle fixed 10 h after lesioning and labeled with phalloidin, demonstrating formation of a leading edge actin ring. B, An E18 utricle treated with 1 μm cytochalasin D and fixed 10 h after lesioning. Phalloidin labeling shows that cytochalasin blocked formation of the actin ring, leaving an irregular-shaped lesion. C, An E18 utricle treated with 50 μm Y-27632 and fixed 10 h after lesioning. Phalloidin shows that an actin ring formed and that the edge of the lesion rounded up and became smooth.