JOURNAL OF ASSISTED REPRODUCTION AND GENETICS, cilt.32, sa.4, ss.653-659, 2015 (SCI-Expanded)
Purpose To study the effect of α-linolenic acid (ALA) on meiotic maturation, mRNA
abundance of apoptosis-related (Bax and Bcl-2) molecules, and blastocyst formation in
ovine oocytes.
Methods A preliminary experiment was conducted to analyze the concentration of ALA
in "small" (≤2 mm) and "large" (≥6 mm) follicles using gas chromatography/mass
spectrometry analysis. The concentration of ALA in small and large follicles was
determined to be in a range of 75.4 to 125.7 μM, respectively. In vitro maturation (IVM)
of oocyte was then performed in presence of 0 (control), 10 (ALA-10), 50 (ALA-50),
100 (ALA-100), and 200 (ALA-200) μM of ALA. Meiotic maturation and mRNA
abundance of Bax, and Bcl-2 genes was evaluated after 24 h of IVM. The embryonic
cleavage and blastocyst formation following parthenogenetic activation were also
determined for each group.
Results The highest concentration of ALA (ALA-200) decreased the oocyte maturation
rate compared with the control group. Analysis of apoptosis-related genes in oocytes
after IVM revealed lesser transcript abundances for Bax gene, and higher transcript
abundances for Bcl-2 gene in ALA-treated oocytes as compared with the control
oocytes. In term of cleavage rate (considered as 2-cell progression), we did not
observe any differences among the groups. However, ALA-100 group promoted more
blastocyst formation as compared with the control group.
Conclusion Our results suggested that ALA treatment during IVM had a beneficial effect on developmental competence of ovine oocytes by increasing the blastocyst
formation and this might be due to the altered abundance of apoptosis-regulatory
genes.