Figure 6.

FSH and LH induce oocyte maturation by downregulating ER levels in vitro. (a) Effects of FSH and LH on oocyte maturation (referred to as GVB) in follicles. Freshly isolated follicles (0 h) were cultured in medium containing FSH or LH for the indicated period of time. *P<0.05, **P<0.01 and ***P<0.001 versus corresponding control (t-test). n=6. (b) Effects of FSH and LH on Nppc and Npr2 mRNA levels in follicles cultured for the indicated period of time. *P<0.05, **P<0.01 and ***P<0.001 versus corresponding control (t-test). n=3. (c) FSH and LH decreased ERα and ERβ levels in follicles. GAPDH served as a loading control. Graph shows the density quantification of WB band (normalization of target protein with respect to GAPDH). Bars represent mean of relative abundance, different letters (a-c) indicate significant differences between groups (P<0.05, ANOVA and Holm–Sidak test). (d) FSH and LH decreased Esr1 and Esr2 mRNA levels in follicles. Esr1 and Esr2 are the corresponding gene names of ERα and ERβ. *P<0.05, **P<0.01, ***P<0.001 versus corresponding control (t-test). n=3. (e) E2 failed to promote Nppc and Npr2 mRNA levels in follicles primed with FSH or LH for 4 h. **P<0.01 (t-test). n=3. Data represent the mean±S.E.M. FSH, 0.1 IU/ml; LH, 1.0 μg/ml; E2, 1.0 μM