AQP4 mRNA expression downregulated in large ovarian follicles (> 25 mm). (A) Semi-quantitative PCR data for AQP-4 in follicles smaller than 10 mm (< 10 mm) and > 25 mm. (B) Normalized AQP-4 mRNA expression levels in follicles < 10 mm and > 25 mm in size. The AQP4 mRNA expression level was normalized to that of GAPDH. Each bar represents the mean ± SD of four independent experiments. *p < 0.05 compared to follicles < 10 mm.