A comparative study of parthenogenetic activation and in vitro fertilization of in vitro matured bovine oocytes

The objective of this study was to determine the effects of 3 chemical agents used sequentially and electrical stimuli on parthenogenetic activation of in vitro matured bovine oocytes and comparison with a standard IVF protocol for embryo developmental rates. For this purpose, oocytes were matured in tissue culture medium-199 (TCM-199) at 39 C and 5% of CO(2) in humidified air. For IVF, matured oocytes were fertilized in Modified Tyrode-Lactate Medium. In the parthenogenetic activation process, direct current (DC) was pulsed (133 V/500 mu m) for 25 mu s and oocytes were sequentially activated with calcium ionophore (CaI) for 10 min, cycloheximide (CHX) + cytochalasin D for 1 h, and CHX for 5 h. After that, all embryos (both IVF and parthenogenetic) were cultured in G1.3/G2.3 media containing 6% CO(2), 5% O(2), and 89% N(2) in humidified air at 39 degrees C.