earticle

영어

Zinc is an extremely important trace element that plays important roles in several biological processes. In this study, we investigated the role of zinc during meiotic resumption and metaphase arrest in in vitro matured porcine oocytes. Oocytes which arrest at GV or MII stage were treated with TPEN, a Zn2+ chelator, respectively. Meiotic resumption and activation were assayed. Effect of PMA, a PKC activator, on GVBD blocking and oocytes activation results from TPEN treatment were checked. Depletion of zinc with TPEN blocked meiotic resumption and results in failure of metaphase II arrest. The p34cdc2 activity in both MII oocytes and GVBD oocytes which treated with TPEN was decreased. Phosphorylated MAPK also be decreased in GVBD stage after TPEN treatment which might be explained by the low expressions of C-mos Cyclin B1 and Cdc2 in GVBD stage. But treated the oocytes with PKC agonist PMA rescued the meiotic resumption and increased MAPK and increases p34cdc2 activity. Treatment oocytes with PMA in GV stage also increased the zinc content in cytoplasm, showed that zinc regulate meiotic resumption is a PKC dependent event. However, although TPEN treatment reduced phosphorylation of PKC substrates in both meiotic resumption and MII stage, rescue the PKC substrates phosphorylation with PMA didn’t prevent the activation of oocytes caused by zinc depletion. These data demonstrate zinc regulates meiotic resumption via a PKC dependent pathway, but independent of that in maintain metaphase arrest in porcine oocytes.