ACTIVATION OF MURINE OOCYTES WITH CA2+ IONOPHORE AND CYCLOHEXIMIDE

A Ca2+ ionophore (A23187, 3 mu M) and inhibitor of protein synthesis ( cycloheximide, 10 mu g/ml) were used sequentially as a unique method f or activating mouse oocytes in vitro. Brief exposure of oocytes to A23 187 followed by 6 hr in cycloheximide resulted in a higher activation rate (93.8%) compared to A23187 or cycloheximide alone (37.7% and 36.5 %, respectively) or the two reagents in reverse order (29.8%). The par thenogenones consistently contained a single pronucleus and second pol ar body, and showed a high degree of developmental potential, as asses sed by transfer to recipient females or addition of a male pronucleus followed by transfer to recipients. This method is a useful way of obt aining large numbers of activated haploid mammalian oocytes for furthe r developmental studies. (C) 1995 Wiley-Liss, Inc.