Effect Of EGCG For The Goat IVM, IVF And The Expression Of BMP15 Gene In The Process Of Oocyte Maturation

Antioxidant level in vitro culture of oocyte and embryo is lower than in vivo development, that's because oocyte and embryo could not benefit from the maternal antioxidant protection when divorced from the donor body. This is a restrict factor in vitro culture. In our experiment we added antioxidant to optimize vitro culture circumstances.EGCG is a natural antioxidant extracted from tea, having no toxico-side effect. In this study, we used goats as animal model, TCM-199 as foundation culture systems, added different levels of EGCG to study EGCG effect on IVM, IVF. Main finding as: in TCM-199 foundation culture systems added EGCG from 0 to 25μM. Discovered that added 15μM EGCG could promote the goats IVC,also during IVM.and significant(P<0.05).Bone morphogeneticprotein 15(BMP15) has identified as important components of oocyte-secreted factors. It was demonstrated to be important in folliculogenesis and oocyte maturation. Recently, the studies were mainly investigated in human, rat, milch goat, cow, procine and so on. However, up to now, the report of the research of the BMP15 about goat were all in multi-foetus. However, majority literature support BMP15 were particular expression in oocyte. Thus, in order to research the biological functions of BMP15 in goat reproductive system, and its expressed level during IVM of gosts oocytes were analyzed.According to BMP15 gene sequences of goat in Genbank, we designed the primers(The primers were designed according to BMP15 gene sequences of goat in Genbank) and regarded the PCR productions as the internal standard. Using semi-quantitative RT-PCR analysis, BMP15 mRNA expression could be seen in different time of cultivate, and finded BMP15 had different expression. The result showed that BMP15mRNA were expressed at low levels in immature oocytes and increased to the highest level at 12 h of IVM, which coincides with the time of cumulus cell expansion, then declined slowly during IVM . so proved it was very significant. The expression pattern of BMP15 suggested that it might be important in cumulus expansion of goats.To study the distribution of BMP15 protein in goats ovary, immunohistochemical analysis was carried out on frozen sections of tissues. The results showed that BMP15 protein were highly expressed in oocytes of follicles from the primary stage onward, but not in primordial follicles. It indicated that it play an important role in folliclar development. Meanwhile, we found BMP15 protein in folliclar antrum that may be secreted by oocytes to regulate the development of follicles.