Growth Differentiation Factor 9 (GDF-9)
GDF-9 belongs to TGFβ family. GDF-9 regulates ovarian function, and plays a vital role for fertility. GDF-9 is mainly expressed in the oocytes of ovarian follicles, and some testicular and hypophyseal expression has been detected. GDF-9 is normally secreted by oocytes, and promotes the growth, development, and survival of human ovarian follicles. GDF-9 binds to TGF-β type II receptors (ALK5 and to BMPRII) and exhibits its biological effect[1][2]. Specifically, the activated type II receptor phosphorylates Smad 2/3 proteins. pSmad 2/3 interacts with Smad4, and finally regulates the expression of target genes. GDF-9 also stimulates the expression of the FSHR, protects cells against atresia, promotes cell proliferation, reduces LHR expression and affects the steroidogenesis of granulosa cells[3]. Human GDF-9 shares about 74% aa sequence identity with mouse.
- [1]. Sanfins A,et al. GDF-9 and BMP-15 direct the follicle symphony. J Assist Reprod Genet. 2018 Oct;35(10):1741-1750. [Content Brief]
- [2]. Hreinsson JG, et al. Growth differentiation factor-9 promotes the growth, development, and survival of human ovarian follicles in organ culture. J Clin Endocrinol Metab. 2002 Jan;87(1):316-21. [Content Brief]
- [3]. de Castro FC, et al. Role of Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 in Ovarian Function and Their Importance in Mammalian Female Fertility - A Review. Asian-Australas J Anim Sci. 2016 Aug;29(8):1065-74. [Content Brief]
