The comparison of developed mouse vitrified preantral follicle with isolated preantral follicles from vitrified ovary

Cryopreservation techniques are useful methods for long-term storage of cells and tissues of the reproductive system. The purpose of this study was to investigate the development and survival rate of vitrified preantral follicles compare with those of isolated preantral follicles from vitrified ovaries.
Preantral follicles of 14 to 16 days-old of NMRI mice ovaries were randomly divided into three groups. Group I: preantral follicles derived from fresh ovaries (control). Group II: preantral follicles derived from vitrified ovaries and group 3: vitrified preantral follicles. After thawing, preantral follicles were cultured in α- MEM medium containing 5% FBS, 100 mIU/ml hFSH, 1% ITS and 10 ng/ ml EGF. At the day 12 of culture, ovulation was induced by adding 1.5 IU/ml hCG. The preantral follicle diameter and the rates of survival, antrum formation and developmental stages of released oocytes were evaluated.
The results showed that the survival rate of vitrified preantral follicles was significantly higher than that of isolated preantral follicle from vitrified ovaries. The mean diameter of preantral follicles, the rates of antrum formation and MII stage oocytes in vitrified preantral follicles were significantly higher than those of isolated preantral follicles from vitrified ovaries.
Vitrified preantral follicles were more suitable to develop to mature oocytes in comparison with isolated preantral follicles from vitrified ovaries.