WCRB2014 POSTER PRESENTATIONS (1) (335 abstracts)
1Chungbuk National University, Cheongju, Republic of Korea; 2Catholic University of Daegu, Daegu, Republic of Korea.
Introduction: Zinc is an extremely important trace element that play 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.
Materials and methods: 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.
Results and discussion: 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 didnt prevent the activation of oocytes caused by zinc depletion. These data demonstrate zinc regulate meiotic resumption via a PKC dependent pathway, but independent of that in maintain metaphase arrest in porcine oocytes.