earticle

영어

This study investigated the effect of Charcoal-Dextran Stripped fetal bovine serum (CDS FBS) and heat-inactivated FBS (HI FBS) in maturation medium on their ability to support in vitro oocyte maturation, cumulus cell-oocyte gap junctional communication, and development of bovine embryos. Oocytes were cultured in TCM-199 supplemented with either 8% BSA, 10% CDS FBS, or 10% HI FBS and 1 μg/mL estradiol-17β, 10 μg/mL FSH, 10 ng/mL EGF, 0.6 mM cysteine, 0.2 mM sodium pyruvate, and followed by in vitro fertilization and the zygotes were cultured in SOF-BE1 medium. The developmental ability and quality of bovine embryos were determined by assessing their cell number, lipid content, mitochondrial activity, gene expression, immunocytochemistry, and cryo-tolerance. The differences in embryo development between experimental groups were analyzed by one-way ANOVA. We have shown that CDS FBS had a higher significant (p<0.05) effect on the rate of blastocyst formation comparing to HI FBS and BSA (45.2±0.7% vs. 37.4±1.5% and 31.1±3.9%, respectively, six replicates were performed). Culture of oocytes with CDS FBS increased (p<0.05) the expression of gape junction proteins, CX37 and CX43, at both transcriptional and translation levels. We also found that CDS FBS significantly increased total cell number and decreased the apoptotic index in day-8 blastocyst comparing to BSA group. Furthermore, the beneficial effects of CDS FBS on embryos were associated with significantly reduced intracellular lipid content and increased mitochondrial activity in both oocytes and blastocyst. Taken together, these data suggest that supplementation of maturation medium with CDS FBS affect cumulus cell-oocyte gap junctional communication, and subsequently improved in vitro developmental competence of bovine oocytes and embryos.