Protein quantification related to the lipid metabolism of cumulus cells during in vivo and in vitro maturation of bovines oocytes

Abstract

The development of in vitro embryo production (IVP) methodology to maximize genetic improvement and animal production at lower cost is a research challenge and it has been studied for many years (Rumpf, 2007). There are evidences that the IVP embryos are more sensible to cryopreservation than the ones produced in vivo and that the reduced cryotolerance is related to high lipid content present into the cytoplasm of these embryos (Abe et al., 2002; Mucci et al., 2006). Previous data demonstrate failures related to the lipid and mitochondrial metabolism in the oocyte during in vitro maturation when compared with in vivo maturation (del Collado et al., 2015), and some metabolic pathways seems to be strictly related with regulation of intracellular lipid reserves mobilization of matured oocyte (S. M. Downs et al, 2002; C. Holm, 2003), as well as differential expression of some genes. Studies conducted by our research group (unpublished data) determined the gene expression of three genes related to lipid metabolism - PLIN2, SREBP1 and FABP3 - in cumulus cells of immature and in vitro- and in vivo-matured oocytes. The results demonstrated high levels of transcripts of these genes after IVM process. Therefore, this project aims to quantify the proteins from these genes in cumulus cells after in vivo and in vitro oocyte maturation. It is expected a larger amount of these proteins in the in vitro process. This project will elucidate aspects still unknown about the differences in lipid metabolism in the cumulus cells during in vivo and in vitro maturation processes.