The Expression Of Gdf-9Protein In Mice Ovaries At Different Age

Researches on the relationship between the oocyte and follicles somatic cell showedgrowth factors oocyte secreted through a complex process of paracrine signals directlyinduced follicular development. Growth differentiation factor-9(GDF-9), secreted by theoocyte,seems essential for normal function of oocyte and granulosa cells and formation oftheca cells. Higher level of GDF-9protein in follicular fluid has significant relationshipswith nuclear maturation of oocytes and embryo quality. Distribution studies on GDF-9proteinin ovarian tissue of animals indicated that GDF-9protein were mainly detected in oocytes.There was also information reported the distribution of GDF-9protein was also in granulosacells. the distribution of GDF-9protein in ovarian tissue from different species has difference.In this study, we used4,6,8,10,12,14,16-week-old kun-bai mice as experimental animalsand used tissue section technique,Hematoxylin&Eosin staining method andImmunohistochemical SP method to research GDF-9protein expression pattern of differentweek-old mice ovaries and follicles at different developmental stages. The results showed thatGDF-9protein follicles had no expression in primordial follicles,was expressed in oocytes inthe primary follicles, secondary follicles, and mature follicles. And GDF-9protein wasexpressed in residual zona pellucida of atretic follicles.The expression of GDF-9proteinshowed dynamic changes. With the growth of mice. The expression of GDF-9proteinincreased rapidly from4weeks to10weeks, and at10weeks of age, the expression of GDF-9protein was up to the highest level, and then showed slow downward trend, but theexpression of the16weeks was higher than that of4weeks. One-way ANOVA analysisshowed the expression of10weeks and that of12weeks were significantly higher, comparedwith other weeks, and the expression of GDF-9protein among groups showed extremelysignificantly different(p<0.01).At first, GDF-9protein expression in different developmentalstages of follicles gradually increased from primary follicles to secondary follicles,and thengradually reduced from secondary follicles to mature follicles, and that of atresic follicle wasdown to the lowest level.The expression of GDF-9protein in atresic follicle was verysignificantly different, compared with that of primary follicle, secondary follicle and mature follicle(p<0.01).GDF-9protein expression of secondary follicle indicated that the extremelysignificant difference(p<0.01), compared with that of primary follicle, mature follicle andatresic follicle.The results demonstrated that GDF-9protein promoted follicular development. Andviability and function of follicles and ovaries could be assessed by detection of ovarian GDF-9protein expression.