Effect of caffeine supplementation during in vitro maturation on parthenogenetic diploid embryo development

Abstract

“Oocyte aging” refers to degradation of oocytes which is considered as the consequence of long time nuclear transfer manipulation which leads to the reduced success rate of somatic cell nuclear transfer (SCNT) embryos. Caffeine, which has an ability of maintenance of the maturation-promoting factor (MPF) from oocyte metaphase, is considered as an improvement factor of oocyte quality. However, the influence of caffeine in aged oocytes in which period of oocyte development is still unknown. Therefore, in this study, the presence of caffeine in the in vitro development of porcine embryos from metaphase I to metaphase II was examined on the parthenogenesis models and evaluated its effect in aged oocyte quality. After reaching metaphase I stage (27 hours) of in vitro maturation (IVM), oocytes were continuously cultured with or without 5mM caffeine until metaphase II (42 hours), then recover in recover medium for 6 hours before parthenogenesis activation. As a result, the supplementation of caffeine during metaphase I to metaphase II of oocyte development has not enhanced the frequencies of matured oocytes. However, there was noticeable significant improvement in rate and quality of parthenogenetic diploid blastocyst of aging oocytes treated with caffeine compared with non-treated group (39.1% and 10.3%, respectively). Furthermore, the DNA fragmentation in blastocysts derived from the non-treated group was observed. Hence, the interpretation of caffeine supplementation during metaphase I to metaphase II could improve the quality of parthenogenetic diploid embryos and quality of parthenogenetic diploid blastocysts developed from aging oocytes (6 hours). Keywords: porcine oocyte, caffeine, parthenogenesis activation, oocyte aging, in vitro maturation