بررسی فولیکول های آنترال تخمدانی برای تعیین غلظت اسید آلفا- لینولنیک موثر بر توانایی تکوین برون تنی اووسایت های بز

Besides their role in making energy, polyunsaturated fatty acids can affect on ovarian follicles and corpus luteum by providing the precursors required for the synthesis of signaling molecules such as steroids and prostaglandins. The effects of α-linolenic acid (ALA) on developmental competence of oocytes in goats were evaluated in this study. Initially, ALA content of follicular fluid of small and large follicles was determined using GC–mass chromatography. Our results indicated that the ALA concentration was in a range of 64.6 to 100.6 μM for small and large follicles, respectively. Then, based on preliminary results, goat oocytes were matured in presence of 0 (Control), 10 (ALA-10), 50 (ALA-50), 100 (ALA-100) and 200 (ALA-200) μM of ALA. Twenty four hours after in vitro maturation (IVM), oocytes in each group were evaluated for their cumulus cell expansion and also for their maturation rate. Furthermore, matured oocytes were treated for parthenogenetic activation and the cleavage and blastocyst rates of control and ALA-treated group were recorded at day 3 and 8 post-activation. Data from each stage were recorded and analyzed via Compare Means Test and/or chi-square analysis using SAS software. Supplementation of maturation media with different concentration of ALA had no effect on cumulus cell expansion except in the highest concentration (ALA-200) that decreased the cumulus cell expansion (P˂0.05). Our findings indicated that maturation rate was higher (P˂0.05) in ALA-50 group as compared with the control group (68.1% vs. 58.2%). Moreover, supplementation of maturation medium with 50 μM ALA improved the cleavage rate (65.2% vs. 52.8%) and blastocyst rate (25.1% vs. 16.7%) as compared with the control group (P˂0.05). Collectively, our results showed that treatment of maturation medium with optimum concentration of ALA had a beneficial effect on oocyte maturation by increasing the maturation rate and this in turn, can stimulate the embryonic development.