Effects Of Melatonin On Pig Oocyte Development In Vitro

Melatonin (MT) is a kind of indoles hormone, mainly secreted by the pineal gland of the brain in human and mammals, other organs and cells also secrete a small amount of production. It is largely affected by light and presents the circadian rhythm, night more commonly, less during the day. MT can through the cell membrane, and various kinds of membrane structure into organelles to give play to the role of antioxidant. The antioxidant, ant apoptotic effect of MT on mice, sheep, chickens and other animals in vitro maturation of oocytes and early embryo were reported, but less reported in pig in vitro maturation of oocytes. This study use pig oocytes as test object, studies the influence of melatonin in vitro maturation of oocytes and embryo development. The main contents are as follows:1 The effects of melatonin on pig oocyte development in vitro(1)The effects of melatonin on pig oocytes maturation in vitroSelected qualified oocytes, then randomly divided into 6 groups, adding melatonin (OM,10-11M,10-9M,10-7 M,10-5M and 10-3 M, respectively) to the cultures of maturation in vitro cultivating 46h, then statist iced the polar body rate of oocyte. Results show that polar body rate of 10-9 M group (77.54%) and 10-7M group (69.2%) is significantly higher than control group (67.81%) and the other group, no significant difference between the two groups.(2) The effects of melatonin on pig oocytes parthenogenetic embryonic developmentSelect qualified oocytes matured 46h without melatonin in vitro, then parthenogenetic activation and randomly divided oocyte into six groups, adding melatonin (OM,10-11M,10-9M,10-7M,10-5M and 10℃, respectively) to embryo cultures to cultivation. The 2th day of embryo culture statist iced cleavage rate, the 7th day statist iced blastocyst rate. It was found that melatonin does not significantly improve oocyte parthenogenetic embryos cleavage rate between the control group and the experimental groups. Blastocyst rate of 10-5M group (20.31%) was significantly higher than 10-3M group (10.68%) and control group (9.45%).(3)The effects of melatonin on pig oocyte development in vitroMature fluid and embryo cultures respectively add 10-9M,10-5M melatonin, oocytes matured 46h in vitro, and statist iced the cleavage rate. Continuing embryo culture after parthenogenetic activation, the 2th day statist iced cleavage rate, the 7th day statist iced blastocyst rate. The results show that the cleavage rate (77.68% VS 81.37%) and blastocyst rate (17.89% VS 19.27%) of control group and experimental group there was no significant difference, the polar body rate of experimental group (78.03%) was significantly higher than control group (64.55%).2 The effect of melatonin on GPx4 and Caspase-3 Expression of porcine oocyte development in vitroIdentify whether exogenous melatonin affect the expression of porcine embryos in vitro GPx4 and Caspase-3 gene at transcription level by RT-PCR, exploring the mechanism of porcine embryos development in vitro. Cultured porcine oocytes in vitro maturation and parthenogenetic activation embryo after adding melatonin, collect IVM 16h,24h,46h pig oocytes and 2-cell,4-cell and blastocyst stage parthenogenetic embryos, identified the expression of genes transcription level by RT-PCR. Melatonin could significantly upregulate anti-apoptotic gene expression of GPx4 of porcine oocyte embryo stage in vitro (P＜0.05), inhibit the expression of pro-apoptotic gene caspase-3 during whole process of culture (P<0.05).