The optimized research of the in vitro culture of preantral follicles in mice

Abstract

Objective: Efficiency of preantral follicle culture in vitro is low and is dependent on species, development stage, and follicle-stimulating hormone (FSH) concentration. Here, we optimized the preantral follicle in vitro culture system in mice. Methods: The primary follicles (PM follicles, 80-100 μm diameter) and early secondary follicles (ES follicles, 110-130 μm diameter) isolated from 14-day female mice were cultured in mediums containing 10 mIU/mL or 100 mIU/mL r-FSH. The follicle growth and oocyte maturation were observed. Estradiol (E2) was detected by ELISA. FSH receptor (FSHR), Ki-67, 3β-HSD, CYP17, and CYP19 levels were detected by immunofluorescence and Western blot. Results: The antrum formation and oocyte maturation rates of ES follicles were significantly higher than those of PM follicles (P