Linolenic acid improves oocyte developmental competence and decreases apoptosis ofin vitro-produced blastocysts in goat

Abstract

SummaryThe effects of α-linolenic acid (ALA) on developmental competence of oocytes in goats were evaluated in this study. Initially, the level of ALA in small and large antral follicles was determined to be in a range of 0.018–0.028 mg/ml (64.6–100.6 μM, respectively).In vitromaturation was performed in the presence of various concentrations (10, 50, 100, or 200 μM) of ALA. Cumulus expansion, meiotic maturation, levels of intracellular glutathione (GSH), embryonic cleavage, blastocyst formation following parthenogenetic activation (PA) andin vitrofertilization (IVF), number of total and apoptotic cells in blastocyst, and expression ofBax, Bcl-2, and p53 genes in blastocyst cells were determined. Compared with the control, no improvement was observed in cumulus expansion in ALA-treated groups. At 50 μM concentration, ALA increased meiotic maturation rate but had no effect on GSH level. When oocytes treated with 50 μM ALA were subsequently used for PA or IVF, a higher rate of blastocyst formation was observed, and these embryos had a higher total cell number and a lower apoptotic cell number. Expression analyses of genes in blastocysts revealed lesser transcript abundances forBaxgene, and higher transcript abundances forBcl-2gene in 50 μM ALA group. Expression ofp53gene was also less observed in ALA-treated blastocysts. Our results show that ALA treatment at 50 μM duringin vitromaturation (IVM) had a beneficial effect on maturation of goat oocytes and this, in turn, stimulated embryonic development and regulated apoptotic gene expression.