The Effect of Different Voltages and Durations on Developmental Rate of Electrofused two Cell Bovine Tetraploid Embryo

Purpose: The values of embryonic stem-like cell and cloning are evident. Production of cloned tissue and animals can be achieved by aggregation and injection of these cells into a tetrapolid morula and blastocyst respectively. Tetraploid embryo is used as a feeder for growth and development of stem-like cell can be produced in vitro by electrofusion of two-cell embryos. The aim of this study was to assess the effect of voltages and durtions on developmental rates of bovine two cell electrofused tetraploid embryo and its comparison with control groups. Materials and Methods: After in vitro maturation and fertilization of cumulus oocyte complexes, two-cell embryos were categorized into three groups: I-Fused group (FG) include two-cell embryos fused by exposure to different voltages (0.5, 0.75, 1, 1.25 & 1.5 kV/cm) and durations (20, 40, 60, 80 & 100 cs). 2- Exposed control group (ECG), two-cell embryos that remained unfused after electrofusion. 3- Unexposed control group (UCG), two-cell embryos culture without exposure to any electrofusion. The embryos from each group were cultured in SOFI and SOF2 and their developmental rates were compared in each group. Results: Increase voltage results in significantly lower developmental rate.The increased duration in high voltages caused decreased blastocyst formation rate, and in low voltage caused increased blastocyst formation rate.The developmental rate in ECG is as trend as FG, and significantly (p<0.05) they were lower related to UCG. Conclusion: The best blastocyst formation rate was obtained in 0.75 kV/cm for 60µs duration.