Effect of cysteamine during in vitro maturation on buffalo embryo development

The purpose of this study was to evaluate whether the addition of cysteamin e during in vitro maturation (IVM) of buffalo oocytes enhances embryo devel opment. Cumulus-oocyte complexes (COC) from slaughterhouse ovaries were mat ured in vitro in TCM 199 supplemented with 10% fetal calf serum (FCS), 0.5 mug mL(-1) FSH, 5 mug mL(-1) LH, I mug mL(-1) 17 beta estradiol and 0 (cont rol), 50, 100 or 200 mu mol L-1 of cysteamine for 24 hours. The matured ooc ytes then were fertilized and cultured for 7 days. No beneficial effect on maturation and cleavage rate was related to the add ition of cysteamine. However, the percentage of embryos that developed to c ompact morula and blastocyst stage was significantly higher (P less than or equal to0.01) for oocytes matured in medium containing 50 mu mol L-1 of cy steamine than it was for oocytes matured with 0, 100 and 200 mu mol L-1 cys teamine (22.6% vs 14.9%, 15.7% and 13% respectively); moreover, the additio n of 50 mu mol L-1 of cysteamine during IVM significantly (P less than or e qual to0.01) increased the proportion of transferable quality (Grades 1 and 2) embryos (19.3% vs 11.3%, 11.6% and 11.2% respectively). The present study showed that adding a thiol compound (such as cysteamine) to the IVM medium improves buffalo in vitro embryo production (IVEP) effici ency, which so far has been unsatisfactory. (C) 2000 by Elsevier Science In c.