Fig. 8. Cofilin activity is required for the development of surface protrusions in blebbistatin-treated cysts. Caco-2 cells were embedded for 72 hours into 3D Matrigel in the presence of adenoviruses bearing either control EGFP (A) or an EGFP-tagged inactive S3E cofilin mutant (B), followed by 12 hours of treatment with blebbistatin. Inhibition of cofilin activity significantly attenuated the formation of blebbistatin-induced surface protrusions (D) (^*P<0.01). (C) Caco-2 cells were grown in 3D Matrigel in the presence of adenoviruses bearing an EGFP-tagged constitutively active S3A cofilin mutant. Overexpression of active cofilin induced the formation of F-actin-rich processes on the cyst surface.