342 EFFECTS OF MELATONIN ON PREIMPLANTATION DEVELOPMENT OF PORCINE PARTHENOGENETIC EMBRYOS
J.-T. Kang A , O.-J. Koo A , D.-K. Kwon A , S.-J. Park A , M. Atikuzzaman A , N. Gomez A , G. Jang A and B.-C. Lee AA Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea;
B Transplantation Research Institute, Seoul National University Medical Research Center, Seoul 110-744, Korea
Reproduction, Fertility and Development 22(1) 327-328 https://doi.org/10.1071/RDv22n1Ab342
Published: 8 December 2009
Abstract
In mammalian species, melatonin is a multi-functional pineal gland hormone that regulates several circadian and seasonal rhythms including reproduction. However, the melatonin study was not common as to the oocytes in the pig. Recently, we reported that exogenous melatonin has beneficial effects on nuclear and cytoplasmic maturation during porcine oocyte IVM and we also reported an existence of melatonin receptor on the cumulus cells and granulose cells (Kang JT et al. 2009 J. Pineal Res. 46(1), 22-28). In this study, as adding further experiments rather than our previous study, we investigated effect of exogeneous melatonin (10 ng mL-1) on the porcine oocytes and analyzed possible factors which can be responsible for that results. Oocytes were recovered by aspiration of slaughterhouse ovaries, and then matured in TCM-199 supplemented with EGF, insulin, pyruvate, cystine, and gonadotropin. Expression of apoptosis-related genes mRNA in oocytes cultured with melatonin were evaluated by real-time PCR (Exp 1), cumulus cell expansion on COC was assessed on the microscopes during in vitro maturation (Exp 2), and developmental effects between melatonin treatement group and non-treatment group on the in vitro culture of parthenogenetically activated oocytes was investigated (Exp 3). In results, oocytes matured with melatonin were assessed for the expression of apoptosis-related genes Bcl-xl (anti-apoptotic gene) and Bax (proapoptotic gene) by real-time quantitative PCR. Analysis of data showed that the expression of Bcl-xl was higher compared to the control while the expression of Bax was decreased relative to the control (P < 0.05). Cumulus cell expansion was evaluated under a stereomicroscope at 22 h, 44 h during IVM. Representative photomicrographs of porcine COC at the start of the IVM, after 22 h and 44 h treatment with melatonin, are shown in Figure. After 22 h of melatonin treatment, cumulus cells were visually expanded compared with non-treatment group. We analyzed significantly greater proportion of parthenogenetically activated oocytes developed to blastocyst when the IVM medium was supplemented with melatonin. Melatonin treatment in the IVM has consequently beneficial effect on the blastocyst formation rates on the development of porcine parthenogenetic embryos (15.4%) compared to non-treatment group (10.7%, P < 0.05). However, cleavage frequency was not affectedby the treatment. In conclusion, the present study demonstrated that melatonin had a beneficial effect on the development of parthenogenetically activated porcine embryos, probably through decreased apoptosis rate and increased cumulus cell expansion.
This study was supported by Korean MKE, MEST (BK21 program), and Hanhwa L&C
