A total of 100 individuals of juvenile Atlantic salmon (Salmo salar L .) with body weight of(165 ± 15)g were divided equally into two groups and fed diets containing fish oil or soybean oil for 5 months at water temperature of 10 ℃ and a salinity of 32-34 .The fatty acid composition was analyzed in the livers and the hepatocytes was isolated and cultured for 24 h in 3 individuals sampled randomly from each group . Then total RNA in the cells was extracted and the relative expression of stress biomarker genes of glutathione peroxidase (GSH-Px) ,heat shock protein 70 (HSP 70) ,metallothionein (MTA) and ubiquitin was studied by RT-PCR to evaluate the effect of dietary fish oil (FO) and vegetable oil (VO) on stress in Atlantic salmon .The results showed that the fatty acid composition of the liver was affected by different oil based diet while the growth was not found significantly different between the two groups (P>0 .05) . There was very significantly higher relative mRNA expression of the four stress biomarkers in the hepatocyes of the fish fed the diet containing VO than the fish fed the diet containing FO (P< 0 .01) , indicating that VO induced higher stress state for Atlantic salmon .The findings provided the valuable information for the feasibility of replacing dietary FO with VO in Atlantic salmon diet .%在水温10℃、盐度32～34条件下，将体质量（165±15） g的大西洋鲑幼鲑100尾平均分为两组，并分别投喂以鱼油和大豆油为油源的两组试验饲料，经过5个月的饲养，称取鱼体质量后，每组随机采取3尾鱼的肝脏样品进行脂肪酸组成测定，另外每组随机选取3尾鱼，分离并培养其肝细胞，24 h后以TRIZOL法提取肝细胞总RNA ，以RT-PCR法检测谷胱甘肽过氧化物酶、热应激蛋白70、金属硫蛋白和泛素等4个应激基因的相对表达量，以研究不同油质对大西洋鲑应激状态的影响。试验结果表明，两组间大西洋鲑的终末体质量差异不显著（P＞0．05），而大西洋鲑肝脏脂肪酸组成受饲料脂肪酸组成的影响，同时植物油组的泛素等4个基因的相对表达量均显著高于鱼油组（P＜0．01），表明在植物油源试验饲料的饲喂下，大西洋鲑肝细胞处于更高的应激状态，为大西洋鲑饲料油源的合理选择提供了有益参考。
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