Efecto de la suplementación con L-cisteína en la maduración in vitro de ovocitos bovinos

in vitro fertilization (ivf) is now a routine technique in a number of biotechnology research laboratories worldwide. ivf is used as a tool for the study of various aspects related to oocytes maturation, fertilization and early embryo development. l-cysteine constitutes an external substrate required for synthesis of glutathione in the maturation of cattle oocytes. in order to study the effect of l-cysteine supplementation on in vitro maturation of cattle oocytes, ovaries were obtained from crossbred cows culled at a local slaughterhouse. three different in vitro maturation treatments were utilized. each treatment had a different concentrations of l-cysteine: t1: 0 mm, t2: 0.1 mm and t3: 1.0 mm. approximately 400 cumulus oocyte complexes (cocs) were matured in wells of 500 ìl of maturation medium (tcm-199), with 5% co2 at 38.5°c and saturated relative humidity. data were analyzed using analysis of variance (anova). there were no significant differences between treatments in term of oocytes that arrived to metafase ii (mii, t1: 72.77%, t2: 67.47% and t3: 70.43%). results indicate that supplementation with l-cysteine during maturation did not possitively affect the percentage of bovine oocytes that reached the m ii state. nonetheless further research should be carried out to determine the effect of l-cysteine supplementation during maturation, on fertilization and on embryonic development in vitro.