The Preliminary Study About The Effects Of BMP15, FGF8b On Sheep Oocytes Maturation And Early Embryo Development In Vitro

With applicated by embryo engineering and technology in the field of human assistedreproduction and livestock breeding, people had given more attention to the IVM of oocytes.However, the lower rate of IVM of oocytes and early embryo development blocked after IVF,had been awlays the factors which had affected the production of mammal animals in vitro.We studied the influences of the methods of collecting oocytes, hormone and cultivating timeon IVM of sheep oocytes. And the effects cytokines BMP15and FGF8b on sheep oocytesmaturation, fertilization and early embryo in vitro was also studied. The main study results areas follows:1. Adopting two kinds of methods to obtain oocyte: slicing and aspiration. The resultsshowed that slicing method was superior to aspiration method, which got more the averageoocytes. The rate of IVM of cutting eggs was66.06%, and the latter was62.96%. There weremost siginificant between them (P<0.01).2. The experiment aim is to compare the effects of different culturing media on IVM: addestrus sheep serum (ESS) and FSH, LH and FBS in the culturing media respectively. Theoccytes were cultured in the conditions of38.5℃and5%CO2saturated humidity. Thematural rate of IVM of adding FSH, LH and FBS was70.53%, but the maturation of addingESS was54.74%. There were most significiant difference between them (P<0.01).3.Sheep occytes were cultured in38.5℃,5%CO2and saturated humidity for20hours,22hours,24hours and26hours. It is higher in22and24hours group compared with20hours group (P<0.05), and there were no differences between22hours and24hours (P>0.05),which was lower than the26hours group (P<0.01). The matural rate of occytes cultured26hwas the highest.4. The mature solution was regarded as the control group. In cultural solution, we addedBMP15, FGF8b respectively as treatments group. The experiment aimed at to study theeffects of different solutions on IVM, IVF, and IVC of sheep occytes. The results showed thatthe group of adding BMP15had higher rate of IVM and embryonic development than thegroup of adding FGF8b and the control group. There were most significant differences between them (P<0.01). The control grouo and the group of adding FGF8b had no differencebetween them (P>0.05).5. The mature solution was regarded as the control group. We added BMP15, FGF8brespectively in mature solution as treatments group. The occytes were cultured26h. Afteroccytes was cracked, the mRNA expressions of Bcl-2and Bax were evaluated by RT-PCR，respectively．The results showed that in BMP15treatment group, the rate of expression ofBcl-2and Bax genes was higher than the control group and the FGF8b treatment group.Theresult implied that BMP15maybe can promote to make sheep oocytes mature.