Dynamics of nuclear and cytoplasm maturation of bovine oocytes cultivated in vitro in medium supplemented with fulerol

Abstract

The aim of this work was to evaluate, in vitro, the dynamics of nuclear and cytoplasmic maturation of bovine oocytes in traditional IVM medium (CT) and supplemented with fullerol (MF50), for 36 hours. The nuclear maturation of CT (n=300) and MF50 (n=270) every 6 hours, stained with Hoechst33342 and cytoplasmic, the mitochondrial distribution of CT (n=197) and MF50 (n=159) at every 12 hours, stained with Mitotracker Orange. At 6 hours, CT oocytes (19%) were in MI (metaphase I), while in MF50 they were in GV (germ vesicle) or GVB (GV breakeage), repeating at 12 hours. At 18 hours, 46.3% were matured in CT, and 20% in MF50. At 24 hours, 43.9% of maturation was observed in the MF50 group, and 63.8% in the CT. At 30 and 36 hours, the maturation pattern was stable, but with the onset of oocyte degeneration. There was a delay in cytoplasmic maturation with 36 hours (P<0.05) in MF50 (53.9% of mature gametes), compared to CT (69.8%). With immature cytoplasm, they were 10.4% and 31.7% for CT and MF50 (P<0.05), respectively. It was concluded that fullerol possibly interfered in the expansion of cumulus oophorus cells, as well as delayed the meiotic progression and cytoplasmic maturation.