Abstract
The present study was carried out to investigate the parthenogenetic development rate into blastocyst of in vitro matured bovine oocytes.
In Experiment 1, in vitro mature oocytes without cumulus cells for 30 h were activated by electric pulse (EP; 150 V/mm, 90 μsec) or Ca-ionophore (IA; 5 μM, 5 min) treatment, and were cultured in TCM-199 + 5 % calf serum (CS) supplemented with cytochalasin D for 1018 h. These ova were cultured in CR1aa + 5 %CS for 7 d. Developmentrates up to blastocyst of ova activated by EP or IA treatment were 7 % and 9 %, respectively.
In Experiment 2, in vitro matured oocytes without cumulus cells for 24 h were treated with EP (at 24 h from the beginning of in vitro maturation:100 V/mm, 90 μsec) + cycloheximide (CY; 24 to 30 h), EP (24 h) + CY (24 to 30 h) + IA (30 h) or IA (24 h) + EP (25 h) + CY (24 to 30 h). The activated ova were treated with cytochalasin D (24 to 42 h) and then were cultured in CRlaa + 5 %CS for 7 d. The development rates up to blastocyst were 37% (EP+CY), 49% (EP+CY+IA) or 50% (IA+EP+CY), respectively.
It was demonstrated that bovine activated oocytes can develop to the blastocyst stage. Moreover electric pulse+Ca ionophore+cycloheximide treatment is the optimal activation method for in vitro matured bovine oocytes.
