Expression of growth differentiation factor-9 in rat ovaries

Aim: To investigate the expression and localization of growth differentiation factor-9 (GDF-9) in rat ovary. Methods: The expression and distribution of GDF-9 in different developmental stages of rat ovary is examined by immunohistochemistry and Western blot. Results: Immunohistochemistry's result shows that no GDF-9 is detected in 0～2 days of rat ovary, on the 3rd day postnatal, GDF-9 begins to express in oocytes of some primordial follicles, and it is distinctly detectable in oocytes from primary to matured follicle. And it is further demonstrated by Western blot that there is no GDF-9 protein in 0～2 days of rat (ovary,) and GDF-9 is detectable in the rat ovary from the 3rd day postnatal to the last stage of folliculogenesis. Conclusion: GDF-9 is secreted in the early stage of ovary, and expressed consequently from then on. It suggests that oocyte may regulate the folliculogenesis with some factors like GDF-9.