Fig. 4. Cortical granule translocation is microfilament dependent. Quantitation of cortical granule location following germinal vesicle breakdown shows that disruption of microfilaments severely reduces translocation. (A) Quantitation of cortical granule translocation (%) in the presence of various inhibitors. Error bars indicate ±1 s.d. and the asterisks indicate significantly different from control values at P>0.01 (confidence level determined by Student’s t-test analysis). Treatment with either of two different microtubule inhibitors (nocodozole, C; colchicine, D) shows no significant difference in translocation from control cells (B), whereas treatment with any of three different microfilament inhibitors [cytochalasin D (E), cytochalasin B (data not shown), latrunculin A (F)] has a dramatic inhibitory effect. Recovery from treatment with cytochalasin D suggests that inhibition of translocation does not cause irreparable damage to the cell. Scale bar: 50 µm.