Effect of Conjugated Linoleic Acid On Gene Expressions Involved in Lipid Metabolism in In Vitro Matured Sheep Oocytes

The aim of this study was to investigate the effect of different concentrations of conjugated linoleic acid (CLA) on in vitro maturation (IVM) and lipid metabolism-related genes in oocytes. In vitro maturation of oocyte was performed in the presence of control (0.0), 50, 100, and 200 µM CLA. Nuclear status and mRNA abundance of selected genes were evaluated following 24 h of IVM. Following the IVM, fertilization and embryo culture were carried out in all groups and embryonic development was examined. The addition of 50 µM CLA to the maturation media yielded a higher number of oocytes at MII stage in comparison to the control group (85.3 ±1.94 versus 68.0±3.04). Higher concentration of CLA (200 µM) was significantly decreased (P<0.05) the maturation rate of oocyte (35.6±1.45). Cleavage, and blastocyte rate were higher in the 50 µM CLA group in comparison to the control one. Also, the 200 µM CLA were significantly decreased the cleavage and blastocyst rate (32.87 and 13.69, respectively). The relative expression of perilipin-2 and hormone sensitive lipase were significantly increased following the addition of 50 µM CLA to the maturation media. Higher concentrations of CLA were significantly dropped the mRNA abundance of both perilipin-2 and hormone sensitive lipase gene in the oocyte. The CPT-1 mRNA abundance was not influenced by the addition of different concentrations of CLA to the maturation media. It seems that the 50 µM CLA yielded a higher number of embryo in comparison to the higher concentration of CLA and excessive concentrations of CLA had undesirable effect on oocyte maturation and embryo development of ovine oocyte.