Figure 5. Tpm3 protects cortical actin from depolymerization by cofilin. (A) Phalloidin staining of cortical actin in oocytes injected with control small interfering RNA (siRNA), constitutively active (CA)-cofilin cRNA, or CA-cofilin and Tpm3 cRNAs. The bar represents 10 μm. Red, actin; blue, DNA. (B) Level of cortical actin in oocytes injected with control siRNA, CA-cofilin cRNA, or CA-cofilin and Tpm3 cRNAs. The fluorescence intensity of phalloidin staining in oocytes injected with control siRNA (n = 15), CA-cofilin cRNA (n = 24), or CA-cofilin and Tpm3 cRNAs (n = 30) were measured using ImageJ and the mean value is provided. The box range represents the standard error of the mean, the whiskers represent the standard error, and the line inside the box represents the mean. Statistical significance was assessed by an ANOVA followed by Tukey post-hoc test.*** P < 0.005; **P < 0.01 (C) Distribution of the ratio of the diameter of the polar body to the diameter of the oocyte in oocytes injected with control siRNA, CA-cofilin cRNA, or CA-cofilin and Tpm3 cRNAs. The box range represents the standard error of the mean, the whiskers represent the standard error, and the line inside the box represents the mean. The statistical significance of the difference in oocyte/polar body diameter between control siRNA-injected and Tpm3-targeting siRNA-injected oocytes was assessed by Welch 2-sample t test. ***P < 0.005; *P < 0.05; N.S., not significant.