Effect of caffein treatment on in vitro development parthenogenetic embryos derived from aging oocytes

Abstract

Manipulation experiments, such as: somatic cell nuclear transfer (SCNT), intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF), require long time for complicated processes. This leads to delaying of oocyte activation which is also known as ‘oocyte aging’. Aging oocyte is the main reason of decreasing in oocyte quality as well as embryo development. Caffeine is considered as an effective factor in rescue aging oocytes due to ability of maintenance high level of activated maturation-promoting factor (MPF) in oocytes. However the effect of caffeine to porcine oocytes during stimulation delaying as well as the optimized concentration of caffeine supplementation has not been determined obviously. Therefore, in this study, the effect of caffeine during in vitro aging was examined and evaluated its successful enhancement of high quality porcine embryos following by electro- parthenogenetic activation. Porcine oocytes were cultured in 42 hours for maturation and then, conducted in vitro aging in 10 hours with different concentrations of caffeine namely 2.5 mM, 5 mM and 8 mM before activation. Aging oocytes decreased the developmental competence of porcine parthenogenetic embryos compare to fresh oocyte at blastocyst stage, 1.9% and 21 %, respectively (p<0.005). Moreover, significant higher blastocyst embryo frequencies was obtained from group of oocytes treated with 2.5 mM of caffeine in comparison with non- treated group, 19.15% and 1.20%, respectively (p<0.005). We concluded that delaying oocyte activation reduces porcine oocyte quality and embryo developmental competence. Beside that, caffeine in 2.5mM of concentration improves oocyte quality during oocyte activation delaying. Keywords: porcine oocyte, caffeine, parthenogenetic activation, oocyte aging, in vitro maturation