ACTIVATION OF IN-VITRO MATURED PIG OOCYTES BY COMBINED TREATMENT OF ETHANOL AND CYCLOHEXIMIDE

Activation of meiosis in oocytes by artificial means is important in s tudies of oocyte function. In pigs, it seems that treatment with ethan ol alone is inadequate for efficient activation of oocytes. Data colle cted in cattle, suggested that addition of a protein synthesis inhibit or increased the effectivness of ethanol for oocyte activation. We inv estigated the combined effects of exposure to ethanol and to the prote in synthesis inhibitor cycloheximide, on activation of in vitro-mature d pig oocytes. Treatment with ethanol alone (concentrations 0, 5, 7 an d 10 %) for intervals of up to 3 minutes resulted in very limited acti vation rates (max, 15 %), A culture of IVM pig oocytes with cyclohexim ide alone (10 mu g/ml) for 24 hours did not induce oocyte activation e ither. However, exposure of IVM pig oocytes to 7 and 10 % ethanol foll owed by culture with cyloheximide substantially increased the activati on rate. A maximal activation rate (over 80 %) was observed when oocyt es were treated with 10 % ethanol for 1 min and subsequently cultured with cycloheximide.