Effects Of Melatonin On In Vitro Growth Of Early Antral Follicles And Studying Expression Of Genes Related To Porcine Oocyte Developmental Capability

Abstract

ABSTRACT For a long time, the researches related to reproductive technologies has been obstructed by the insufficient quantity of fully-grown oocytes. Therefore, it is essential to establish a culture system of in vitro growth (IVG) for harvesting the abundant source of growing oocytes from ovary for further application in assisted reproductive techniques. However, the efficiency of pre-existing IVG remains remarkably low due to one of major threats, which is oxidative stress. A powerful antioxidant, Melatonin, which has been applied in human is predicted to enhance IVG outcomes through the preventive effect against oxidative stress. This research aims to evaluate the effect of melatonin during IVG on the growth, meiotic competence, development competence and gene expression of porcine oocyte-cumulus-granulosa complexes (OCGCs) derived from early antral follicles (1- 1.5mm). OCGCs were cultured in IVG with melatonin supplementation of four concentrations (0 μM, 1 μM, 10 μM, 100 μM) for 4 days. The oocyte diameter, survival rate after IVG, and subsequently the meiotic competence after 42 hours of IVM were assessed. Moreover, the parthenogenetic embryos were generated from oocytes and culture in vitro development (IVD) for 7 days (blastocyst stage) to assessed developmental competence of oocytes as well as gene expression of pluripotent and apoptotic genes in blastocyst. The results expressed that growing oocytes treated with 10 μM melatonin acquired the highest significant improvement in meiotic competence and developmental competence compared with the oocytes in non-melatonin group in every aspect including morphology, average diameter, survival percentage, and maturation percentage. In conclusion, melatonin supplementation in IVG at 10 μM has the best enhancement on the growth and meiotic competence of oocytes from early antral follicles