P34^cdc2 Kinase and MAP Kinase Activities and Parthenogenetic Activation in Porcine Oocytes after Injection of Miniature Pig Sperm Extracts

Abstract

The aim of the present study was to examine the rate of activation and time-dependent changes in p34^cdc2 kinase and MAP kinase activities in porcine oocytes after injection of sperm extracts (SE) or treatment with Ca²⁺ ionophore to clarify whether SE injection is useful for porcine oocyte activation. SE was prepared from miniature pig sperm by non-ionic surfactant. Oocytes that were treated with Ca²⁺ ionophore and injected with SE were activated at rates of 41% and 46%, respectively. The activities of p34^cdc2 kinase and MAP kinase in each culture period (4, 8 and 12 h) in the Ca²⁺ ionophore group and SE injection group were significantly lower than those in the control group. These results suggest that SE injection induces decrease of p34^cdc2 kinase and MAP kinase activity, and induces oocyte activation, as well as Ca²⁺ ionophore treatment, but the induction was comparatively limited.