Abstract
In the present study, to elucidate the cause of different developmental potential in porcine oocytes matured in two media, mTCM199 and mNCSU37, we examined the time course of changes in the nuclear states and p34cdc2 kinase activity of oocytes during meiotic maturation. The p34cdc2 kinase activity of oocytes cultured in mTCM199 gradually increased from earlier in the culture time periods than that of oocytes in mNCSU37, and that of oocytes in mNCSU37 rapidly increased from the middle of the culture period, but the oocytes in both media had similar levels of p34cdc2 kinase activity at the end of the culture period. Oocytes cultured in mTCM199 underwent GVBD and reached the MII stage earlier in the culture period than those in mNCSU37. Moreover, MII oocytes cultured in either mTCM199 or mNCSU37 had a similar level of p34cdc2 kinase activity at the end of the culture period. It was therefore concluded that the difference in developmental competence of oocytes matured in different media seems to be independent of p34cdc2 kinase activity.
