P-96: Mechanical Activation of Parthenogenesis in Mouse Oocytes Using Hydrostatic Pressure

Effective protocols are introduced for parthenogenesis activation in oocytes. Hydrostatic pressure can act as a mechanical stimulator that rearranges egg contents, leading to new structural or molecular combination. Alternatively, mechanical stimulation could stimulate a mechanically-gated process, such as opening or closing of stretch activated ion channels. This study, investigated the use of hydrostatic pressure in the activation of parthenogenesis in mouse oocytes matured in vitro. Materials and Methods: Immature oocytes were isolated from 8-week-old female NMRI mice. Oocytes were cultured in α- MEM culture medium containing 7.5 IU HCG under mineral oil for 24 hours. In vitro-matured oocytes with a polar body were subjected to 10 mmHg pressure for 10, 20, 30 minutes (treatments I, II and III). Oocytes without exposure to pressure were considered as control. Oocytes from two groups were culture for 72 hours and embryo development rate was assessed. Results: After 72 hours, cleavage rate in treatments I, II, III and control was 18.27%, 41.92%, 24.72% and 6.44% respectively. The result showed that, oocyte activation rate in all treatments was higher than control (p<0.05). The highest cleavage rate associated with treatment II which was significantly different from treatmentsI, III and control (p<0.05). Conclusion: We inferred that the exposures to hydrostatic pressure in the parthenogenetic activation can improve the development of in vitro matured oocytes.