Abstract: Objective: To explore the effect of alpha-linolenic acid (ALA) on human oocytes maturation and the mitochondrial DNA（mtDNA） copy numbers of oocyte. Methods: A total of 441 morphologically normal immature oocytes were recruited from 273 infertile women underwent ICSI in our Center from October 2014 to October 2015. There were 179 oocytes at MⅠ stage and 262 oocytes at GⅤ stage. Oocytes with the same proportion of MⅠ and GⅤ were randomly divided into 5 groups, and in vitro cultured for 24 hours in the medium with ALA at different level [0（as controｌ）, 10 μmol/L, 50 μmol/L, 100 μmol/L, 200 μmol/L]. The oocyte maturation was observed, and the mtDNA copy numbers in the ALA 0 μmol/L (as control) group and the ALA 50 μmol/L group were determined by real-time PCR. Results: ①The total maturation rate of the ALA 50 μmol/L group （７０．１％） was significantly higher than that of the control group （42.1%） and the ALA 200 μmol/L group （３４．１％, both P＜0.05）. ②The total maturation rate of GⅤ in the ALA 50 μmol/L group （64.4%） was significantly higher than that in the control group （２８．９％） and the ALA 200 μmol/L group （１８．２％, ｂｏｔｈ Ｐ＜０．０５）. ③The mtDNA copy number of in vitro matured oocytes in the ALA 50 μmol/L group （3.64×107±1.85×106） was significantly higher than that in the ALA 0 μmol/L group （3.42×106±1.95×105, P＜0.05）. Conclusions: 50 μmol/L ALA can increase the mtDNA copy number of the in vitro matured human oocyte, suggesting that ALA can promote the in vitro maturation of human oocyte.

Key words: Alpha-linolenic acid, Oocytes, Cell culture techniques, DNA, mitochondrial