The effect of leukemia inhibitory factor and coculture on the in vitro maturation and ultrastructure of vitrified and nonvitrified isolated mouse preantral follicles

ObjectiveTo develop a system for in vitro maturation of preantral follicles isolated from vitrified and nonvitrified mouse ovaries by leukemia inhibitory factor (LIF) and coculture with cumulus cells.DesignExperimental study.SettingUniversity-based research laboratory.Animal(s)Twelve- to 14-day-old National Medical Research Institute female mice.Intervention(s)Vitrification of mouse ovaries and in vitro maturation of follicles.Main Outcome Measure(s)The growth, maturation, steroidogenesis, alkaline phosphatase activity, and ultrastructure of preantral follicles derived from vitrified and nonvitrified mouse ovaries and the developmental capacity of embryos obtained from metaphase II to blastocyst stage.Result(s)The follicular diameters were increased in the presence of LIF in the simple culture, coculture, and vitrified coculture groups. The survival and developmental rates of follicles were not significantly different between groups. The E2 production was increased in all groups during the culture period. Alkaline phosphatase activity was observed in the follicles of cryosectioned slices and cultured preantral follicles. There was no remarkable change in ultrastructural maturation features of cultured follicles.Conclusion(s)LIF alone or in combination with the coculture system increased the growth of cultured preantral follicles but had no effect on their maturation; the ultrastructure, growth, and maturation of vitrified follicles were the same in the cultured groups and in the controls.