| dc.description.abstract | The deterioration in quality of the oocytes, also known as “oocyte aging” due to the long nuclear transfer manipulation duration is supposed to be the main reason of the low success rate of somatic cell nuclear transfer (SCNT). Caffeine with an effect to maintain the maturation-promoting factor (MPF) from the metaphase of oocytes is expected to enhance the quality of the oocytes. Therefore, in this study, the effect of caffeine treatments on the in vitro development of porcine embryos from aged oocytes was examined on the parthenogenesis model with durations of aging for the purpose of evaluate its effect on rescuing aged oocytes, further enhancing the development ability of embryos. After 42-44 hours of in vitro maturation (IVM), oocytes were left for aging in 6 or 8 hours with or without 5 mM or 10 mM caffeine treatments (0 mM, 5 mM, 10 mM caffeine for 6 hours and 0 mM, 5 mM 10 mM caffeine for 8 hours), then electro-activated and cultured for development to 2-cell and 4-cell embryos. Morphologies of embryos developed from aged oocytes treated with caffeine were observed to be maintained as same as the natural morphologies of embryos without undergoing the oocyte aging, with only a little difference in the homogeneity of the cellular cytoplasm. There was a significant difference recorded between oocytes treated and non-treated by caffeine for 6 hours in production of 4-cell embryos (non-treated, 5 mM and 10 mM caffeine treated: 47.06%, 72.73% and 83.33%, respectively). The long duration of aging was observed to cause more serious deterioration in quality of the oocytes that caffeine could not or only partially express its effect, even a reverse effect with high concentration (10 mM). Caffeine treatments with concentrations of 5 mM and 10 mM were recorded to have a similar effect on the aged oocytes. Thus, 5 mM caffeine for 6 hours was suggested to be the best treatment to rescue aged oocytes for the embryo development.
Keywords: caffeine, parthenogenesis, oocyte aging, pig, activation, electro-stimulation, electro-activation | en_US |
