134 SERIAL TREATMENT OF RESVERATROL-TROLOX IMPROVED EMBRYONIC DEVELOPMENT OF PORCINE PARTHENOTES

Abstract

Antioxidants are widely used for in vitro production of embryos due to their activity as reactive oxygen species scavengers. Among various antioxidants, resveratrol supplementation in in vitro-maturation (IVM) media and trolox supplementation in in vitro-culture (IVC) media improves oocyte maturation and embryonic development in other species, such as cattle and sheep. Limited information is available, however, on the effect of resveratrol and/or trolox on porcine embryos produced in vitro. In this study, we evaluated the effect of resveratrol supplemented to the media of IVM and trolox treatment during IVC on porcine parthenotes. We used TCM-199 as IVM media and porcine zygote medium (PZM)-5 as IVC media. For activation, matured oocytes after 44 h of IVM were electrically activated with 280 mM mannitol and cultured in IVC medium (PZM-5). Statistical analyses of all data were carried out using SPSS 17.0 (one-way ANOVA, followed by Duncan's multiple range test). In the experiment 1, a total of 618 oocytes were used in 4 independent replicates to evaluate the effect of 4 different concentrations (0, 1, 2, or 4 μM) of resveratrol during IVM on parthenotes. Oocytes treated with 2 μM resveratrol during IVM had significantly higher cleavage rates and blastocyst formation rates (73.0 and 34.4% v. 64.0 and 18.3%, respectively) than the control group. Experiment 2 involved supplementation with trolox (0 μM, 100 μM, 200 μM, 400 μM) to 957 parthenotes during IVC for 7 days (4 replicates). Cleavage rates significantly increased in the 100 μM group (75.6 v. 69.1%), and blastocyst formation rates in the 200 μM group were significantly higher compared to the control group (33.7 v. 23.8%). To determine the combined effects of resveratrol treatment during IVM and trolox treatment during IVC, in the experiment 3 we selected an optimized concentration (2 μM of resveratrol and 200 μM of trolox) from each experiment and evaluated the combined effects (3 times replicated). We designed 4 groups: (1) control, (2) resveratrol only (R), (3) trolox only (T), and (4) resveratrol-trolox (R-T). The R group and R-T group showed significantly higher cleavage rates than the control group (81.8 and 83.1% v. 72.3%). All treatment groups showed significantly increased blastocyst formation rates compared with the control group (39.2, 37.8, and 38.4% v. 23.7%). There is no significant difference in total cell numbers of blastocyst among the control, R, and T groups (47.8 v. 54.2 v. 54.7). However, the R-T group had significantly more cells than the control group (67.1 v. 47.8). Our results suggest that 2 μM resveratrol treatment during IVM, followed by 200 μM trolox treatment during IVC, improves developmental potential of the parthenotes. For a further study, we will apply this condition to somatic cell nuclear transfer, and we also will verify quantitative PCR analysis of apoptosis-related mRNA expression of PA and somatic cell nuclear transfer embryos. This study was supported by the MOTIE (#10033839), IPET (#311011-05-3-SB010), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.