Cryopreservation Of Goat Oocytes

This paper compared the effects of sucrose, cryoprotectants, the developmental stages of oocytes and freezing methods on oocytes Cryopreservation in goat. The results as follows:1. The Cryopreservation effectiveness of the existence and inexistence of 0.1 mol/L sucrose in 1.8mol/L ethylene glycol (EG) freezing protective solution with a programmed freezing method on goat metaphase II (MII) oocytes were compared. The result suggested that the non-permeability protect-sucrose could significantly improve the oocyte's developmental potency. The existence of sucrose not only had no side effects on the oocytes' morphology after thawing procedure, but also improved the cleavages and blastocyst rates of thawed parthenogenetic oocytes.2. By adding 0.1 mol/L sucrose into the freezing protecting solution including 1.8 mol/L EG, 1.5 mol/L propylene glycol (PROH), 1.5 mol/L dimethylsulfoxide (DMSO) and 1.5 mol/L glycerol(GL) respectively, goat oocytes were frozen at GV stage, lOh and 24h (Mil) post maturation accordingly. The judgment was carried out according to the normal morphological oocyte, cleavage and blastocyst rates after thawing and parthenogensis. The effective protection sequence were EG>PTOH>DMSO>GL. The results demonstrated that EG had the strongest protecting efficiency than others.3. Using EG, PROH, DMSO and GL added with sucrose and the Cryopreservation solutions, goat oocytes at GV, 10h and 24h (MII) post maturation were cryoperservated through programmed procedure. The judgment was carried out according to the normal morphological oocyte, cleavage and blastocyst rates after thawing and parthenogensis. The Cryopreservation effectiveness of Mil oocytes was significantly higher than those of GV and 10h post maturation oocytes. The results demonstrated that MII was suited to cryoproservate.4. Using 1.8 mol/L EG supplemented with 0.1 mol/L sucrose as the Cryopreservationsolutions, the efficiencies of programmed freezing procedure and OPS vitrification procedure on goat GV, 10h and 24h post maturation oocytes were compared. The results showed that though there was no significant difference in oocyte morphology between two procedures, the program cryoperservated oocytes had a significantly higher cleavage and blastocyst rates after parthenogenetic activation than did the vitrificated oocytes.