Abstract: Growth differentiation factor 9 (GDF-9) is a new member of transforming growth factor beta (TGF-β) superfamily. The role of GDF-9 as a factor secreted by oocyte has been broadly discussed in recent years. GDF-9 participates in regulating the differentiation and development of granulosa cells, the production of relative proteins and factors, the expression of genes related to the reproductive system, and the metabolism and apoptosis of ovarian cells. GDF-9 is therefore a vital factor of folliculogenesis, maturation of oocytes, ovulation and luteinization. Furthermore, BMP-15 is another oocyte-derived factor which shares high-homologous amino acid sequences and similar protein structure with GDF-9. GDF-9 and BMP-15 can form a heterodimer, in which they have synergistic effects. Now it′s believed that GDF-9 is an impotant factor of the two-way communication between oocyte and granulosa cells, and that GDF-9 participates in the synchronous communication and coordinated growth of the two kinds of cells. The abnormal expression of GDF-9 may be associated with female reproductive endocrine disorders and subsequent infertility. Here we reviewed the effects of GDF-9 on ovarian function, including the regulation of oocyte development and folliculogenesis.

Key words: Growth differentiation factor 9, Granulosa cell, Cumulus cell, Oocytes, Ovary