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Updated: Aug 7, 2026
A Method for Ovarian Follicle Encapsulation and Culture in a Proteolytically Degradable 3 Dimensional System
Published on: March 15, 2011
Recombinant growth differentiation factor-9 (GDF-9) enhances growth and differentiation of cultured early ovarian
1Department of Gynecology and Obstetrics, Stanford University School of Medicine, California 94305-5317, USA.
Abstract:
Transgenic mice with deletion of the GDF-9 (growth differentiation factor-9) gene are characterized by the arrest of ovarian follicle development at the primary stage. Based on the hypothesis that GDF-9 is important for early follicle development, we isolated rat GDF-9 complementary DNA (cDNA) and generated recombinant GDF-9 protein to study its physiological role. Using bacteria-derived GDF-9-glutathione S-transferase (GST) fusion protein, specific antibodies to the mature form of GDF-9 was generated. Immunohistochemical staining of ovarian sections indicated the localization of GDF-9 protein in the oocyte of primary, secondary and preantral follicles, whereas immunoblotting demonstrated the secretion of GDF-9 by mammalian cells transfected with GDF-9 cDNAs. Recombinant GDF-9 was shown to be an N-glycosylated protein capable of stimulating early follicle development. Growth of preantral follicles isolated from immature rats was enhanced by treatment with either GDF-9 or FSH whereas the combined treatment showed an additive effect. In addition, treatment with GDF-9, like forskolin, also stimulated inhibin-alpha content in explants of neonatal ovaries. In contrast, the stimulatory effects of GDF-9 were not mimicked by amino-terminal tagged GDF-9 that was apparently not bioactive. Thus, the present study demonstrates the important role of GDF-9 in early follicle growth and differentiation. The availability of recombinant bioactive GDF-9 allows future studies on the physiological role of GDF-9 in ovarian development in vivo.
Insights
Growth differentiation factor-9 (GDF-9) is crucial for ovarian follicle development. This study generated recombinant GDF-9 protein, confirming its role in stimulating early follicle growth and differentiation in mammals.
Area of Science:
- Reproductive Biology
- Molecular Endocrinology
- Developmental Biology
Background:
- Transgenic mice lacking growth differentiation factor-9 (GDF-9) exhibit arrested ovarian follicle development at the primary stage.
- This suggests a critical role for GDF-9 in early folliculogenesis.
Purpose of the Study:
- To investigate the physiological role of GDF-9 in early ovarian follicle development.
- To generate recombinant bioactive GDF-9 for further research.
Main Methods:
- Isolated rat GDF-9 complementary DNA (cDNA) and produced recombinant GDF-9-glutathione S-transferase (GST) fusion protein.
- Generated specific antibodies against mature GDF-9.
- Utilized immunohistochemistry, immunoblotting, and in vitro follicle culture assays.
Main Results:
- GDF-9 protein localizes to oocytes in primary, secondary, and preantral follicles.
- Mammalian cells transfected with GDF-9 cDNAs secreted bioactive GDF-9.
- Recombinant GDF-9 stimulated preantral follicle growth, showing additive effects with FSH.
- GDF-9 treatment increased inhibin-alpha content in neonatal ovaries.
Conclusions:
- GDF-9 plays a vital role in the growth and differentiation of early ovarian follicles.
- The availability of recombinant bioactive GDF-9 facilitates future in vivo studies on its function in ovarian development.
