Confirmation of the expression of AQP4 protein in bovine ovarian section by immunostaining. (A) H&E staining of bovine ovarian section. The ovary with follicles < 10 mm in diameter shows antrum, granulosa cell layers (G), theca cell layers (T), and stroma. (B) Immunohistochemical staining of AQP4. AQP4 was visualized using an AQP4 antibody, followed by a secondary antibody conjugated with fluorescein isothiocyanate (FITC, blue). The nucleus was stained by DAPI (blue). Scale bar, 50 µm.