A adição de ácido linoleico conjugado (CLA) durante a maturação in vitro (MIV) diminui a expressão do gene SCD em oócitos bovinos

Abstract

One of the major obstacles to in vitro embryo production (PIVE) is the cryopreservation of embryos, since the rate of pregnancies is reduced after this process. It is suggested that this impairment results from the accumulation of lipids resulting from the use of fetal bovine serum (SFB) in in vitro culture media. The addition of polyunsaturated fatty acids (PUFA), especially linoleic acid (CLA) in the in vitro culture medium of oocytes and embryos has shown promising results in reducing lipids. Thus, the objective was to evaluate the effect of adding conjugated linoleic acid CLA to the in vitro maturation medium (IVM) in the presence of fetal bovine serum (SFB), on the expression of genes related to lipid metabolism. The oocytes from ovary collected in the slaughterhouse were aspirated, selected and then separated into two experimental groups for maturation: MIV (control) and MIV + CLA. After the maturation period, gene expression patterns (FADS2, GREM1, SCD, SREBP1, AREG, COX2) in oocytes and cumulus cells were investigated. There was less (p <0.05) SCD gene expression in oocytes matured in the presence of CLA (0.63 ± 0.12) when compared to the control group (1.04 ± 0.15), whereas in cumulus cells there was no effect on this gene. The addition of CLA did not influence (p> 0.05) the expression of the other evaluated genes (FADS2, GREM1, SREBP1, AREG, COX2) in the oocyte or in the cumulus cells. We conclude, therefore, that the addition of CLA in culture media may be an alternative to improve maturation in vitro, since it reduces the expression of the SCD gene, which is related to lipid metabolism in bovine oocytes.