Correlation of somatic cell steroid secretion and quality of generated oocytes after in-vitro stimulation of mouse follicles

Abstract

Purpose: To test the possibility of follicular somatic cell steroidogenesis as a marker for quality of their embraced oocytes. Methods: Mechanically isolated mouse preantral follicles were cultured and matured in-vitro (IVC/IVM) for study. Results: During IVC/IVM, oogenesis occurred concomitantly with folliculogenesis in a coordinated manner and simultaneously with progressive increments of somatic cell steroidogenesis. Follicular E2 production of matured oocytes were significantly higher than that of immature ones. The majority of MII oocytes (32/36) and all developed blastocysts(12/12) were associated with active E2 production prior to ovulation. In this study, 18 MII oocytes met both requirements for active and optimal E2 production. 13 of them were fertilized and 10 developed into blastocysts. Conclusion: Active somatic cell steroidogenesis prior to ovulation and an optimal steroid milieu at ovulation are prerequisites for generation of competent oocytes after follicular maturation in-vitro. © Springer Science+Business Media, Inc. 2006.