Effects of three different media on in vitro maturation and development, intracellular glutathione and reactive oxygen species levels, and maternal gene expression of abattoir-derived goat oocytes

This study was designed to compare the behavior of abattoir-derived goat oocytes submitted to different in vitro maturation (IVM) treatments. Cumulus-oocyte complexes collected from abattoir ovaries were subjected to IVM in three maturation media, which consisted of TCM199 supplemented either with: (1) 10 ng/ml EGF and 100 μM cysteamine (Defined medium); (2) 10% FCS, 5 μg/ml FSH, 10 μg/ml LH, 1 μg/ml estradiol (FCS medium); or (3) combined components of both Defined and FCS media (Combined medium). After 22 h of IVM, oocyte maturation rate was significantly higher in Combined medium compared to FCS medium (52.0 ± 2.0% vs. 37.7 ± 3.2%, P < 0.05); however, no significant difference (P > 0.05) was observed in maturation rates between Defined (43.4 ± 4.7%) and FCS or Combined medium. There was no significant difference (P > 0.05) in the rates of cleavage, blastocyst, or blastocyst cell number among different maturation conditions. The intracellular glutathione (GSH) level was observed to be significantly higher (P < 0.05) in oocytes matured in Combined medium compared to either Defined or FCS medium. The level of intracellular reactive oxygen species (ROS) was lower (P < 0.05) in Defined medium compared to both FCS and Combined media. Relative mRNA expression analysis of 39 developmentally associated genes revealed that four genes (MATER, PLAT, NANOG, and CCNB1) were differentially expressed between the groups. In summary, our results indicate that similar in vitro maturation rates and developmental ability can be obtained when Defined and Combined maturation media were used and the supplementation of FCS medium with EGF and Cysteamine improves IVM efficiency of goat oocytes.