Effects On In Vitro Maturation And In Vitro Fertilization Of Glutathione In Mouse Oocytes

With the application of embryo biotechnology in human assistant reproduction and animal reproduction, people need lots of high grade embryos for scientific research and commerce. Oocytes undergo in vitro maturation and in vitro fertilization could provide lots of embryos. However, compared with in vivo, the quality of embryo in vitro was very unstable in vitro embryo production and affected the practice of fertilization in vitro and animal cloning. One of the factors influencing oocyte in vitro maturation and in vitro fertilization is reactive oxygen species (ROS) which can reduce the quality of IVM oocyte and the ability of embryo following development after fertilization. As a most important material against ROS damage in oocyte during maturation and fertilization process, glutathione (GSH) can improve the competence of embryo following development. In this present research, we added three kinds of thiol: cysteine, cystine andβ- mercaptoethanol, in maturation medium to stimulate GSH synthesize in mouse oocytes. We also studied that added different concentration of GSH in sperm capacitation medium and in vitro fertilization process for improve the developmental competence of embryo after maturation and fertilization.The results are as follows:1. Cysteine and cystine could stimulate GSH synthesization during mouse oocyte in vitro maturation and enhance competence of embryo development and increase blastocysts cell number. This consequence depended on the concentration of cysteine and cystine. Furthermore, the best concentration of cystine was 200μM, but it could impair the developmental competence of embryo in a higher concentration.2.β-mercaptoethanol could improve the concentration of GSH in mouse oocytes during in vitro maturation. Nevertheless, it could not significantly improve the developmental competence of embryo until 200μM, but a higher concentration had contrary effects. 3. Adding GSH in capacitation medium could improve the fertilization efficiency during spermatozoa capacitation; consequently enhance ability of fertilization in mouse spermatozoa. This consequence depended on GSH concentration.4. Adding GSH in fertilization medium could increase the cleavage and blastocyst rate during in vitro fertilization in mouse. This consequence depended on GSH concentration.