Influência do FSH sobre os aspectos celulares e moleculares na maturação in vitro de complexos cumulus-ovócitos de bovinos

Abstract

Biotechniques applied to bovine reproduction still have limitations and many are linked to a lack of knowledge about an update of macromolecules added to the medium of in vitro oocyte maturation (IVM), embryonic development process and cell difference, as well as genes of inhibitors related to pluripotency in in vitro production in this species. Follicle stimulating hormone (FSH) is present in most IVM protocols because of its importance in large cumulus cells, estradiol synthesis and cytoplasmic and nuclear maturation of the oocyte. However, few studies report an influence of FSH on gene activity during maturation. Considering the identification and modification of the biochemistry of the medium and mechanisms of action of the genes contributed to improvements in the various biotechniques applied to the reproduction to increase the production of animals of high genetic value, this work had the objective of evaluating an influence of FSH in cumulus during maturation of bovine oocytes. Hormonal and biochemical analyzes of the in vitro maturation medium before and MAB, with and FSH (G-FSH, G-FSHIN, G-CTL, G-CTLIN), as well as an analysis of the expression of pluripotency related genes in cumulus of cattle matured with and without FSH (G-FSH and G-CTL) collected in slaughterhouses of the Zona da Mata and Agreste of Pernambuco. A concentration of estradiol was observed by immunoassay and concentration of protein, glycogen, sugar and lipid (biochemical analysis) through a spectrophotometer in the analysis of real-time PCR (RT-qPCR). For statistical analysis, normality was assessed by Shapiro-Wilk test to be submitted to analysis of variance (Test F) and, or Tukey HSD test, level of significance of 5.0%. Increased cumulus cell amplitudes were observed during maturation in the FSH medium when compared to the non-FSH medium. In addition, FSH influences glycogen consumption by cells, decreasing their concentration not medium, due to the need for high energy demand for the process. Influence was observed in the expression of RONIN and CMYC, in which the hormone stimulates RONIN activity and represses CMYC. Thus, FSH influences a maturation of oocytes, besides also acting in the energetic activity of the cumulus-oocyte complex of bovine without cellular and molecular physics.