Ytrestøyl Trine, Afanasyev Sergey, Ruyter Bente, Hatlen Bjarne, Østbye Tone-Kari, Krasnov Aleksei
Nofima AS, Norwegian Institute of Food, Fisheries & Aquaculture Research, Tromsø, Norway.
Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia.
Comp Biochem Physiol Part D Genomics Proteomics. 2021 Sep;39:100841. doi: 10.1016/j.cbd.2021.100841. Epub 2021 Apr 26.
High content of carotenoids in tissues of salmonid species suggests possible functional importance, which has so far remained unclear. The objective of this study was to investigate the effect of astaxanthin on performance and gene expression of sea water adapted Atlantic salmon (Salmo salar) fed diets with low content of marine ingredients (7.5% fishmeal and 5% fish oil). Salmon with start weight 197 g were fed two diets with identical proximate composition except for the content of astaxanthin (<1 and 48 mg/kg, respectively) for 84 days. Absence of dietary astaxanthin caused significant transcriptome changes revealed with DNA microarray. The growth rate was not optimal for the two diet groups but was not affected by dietary astaxanthin concentration. Accumulation of lipid in the intestine and liver was found in salmon fed both diets, indicating malabsorption of lipid. Salmon fed the diet without astaxanthin had larger livers and higher fat content in liver due to accumulation of triglycerides, but the difference in fat content was not significant. Transcriptome responses in different organs suggested that lack of dietary astaxanthin may have functional consequences in salmon fed low marine diets. In the intestine of astaxanthin deprived salmon, decreased expression was observed in a suite of immune genes including genes of innate antiviral immunity, transporters and enzymes of glycan metabolism. Transcriptome responses in liver suggested effect of absence of astaxanthin on lipid metabolism and especially on increased biosynthesis of terpenoids and steroids and only minor effects on immune genes. The greatest transcriptome changes were observed in skeletal muscle in the absence of astaxanthin, with an up-regulation of immune-related genes (119) and multiple genes with well-established association with stress. The condition resembled a mild inflammation of the muscle. Small or moderate scale of gene expression changes were in concordance with equal growth performance of fish fed both diets, however their character may indicate potential risk of absence of dietary carotenoids.
鲑科鱼类组织中类胡萝卜素含量较高，这表明其可能具有重要的功能，但目前尚不清楚。本研究的目的是调查虾青素对食用低海洋成分（7.5%鱼粉和5%鱼油）日粮的海水适应型大西洋鲑（Salmo salar）生长性能和基因表达的影响。初始体重为197克的鲑鱼喂养两种除虾青素含量不同（分别<1毫克/千克和48毫克/千克）外其他近似成分相同的日粮，持续84天。DNA微阵列显示，日粮中缺乏虾青素会导致显著的转录组变化。两个日粮组的生长速度都不是最优的，但不受日粮虾青素浓度的影响。两种日粮喂养的鲑鱼肠道和肝脏中均发现脂质积累，表明脂质吸收不良。喂食不含虾青素日粮的鲑鱼肝脏更大，由于甘油三酯积累肝脏脂肪含量更高，但脂肪含量差异不显著。不同器官的转录组反应表明，日粮中缺乏虾青素可能对食用低海洋日粮的鲑鱼产生功能影响。在缺乏虾青素的鲑鱼肠道中，一组免疫基因的表达下降，包括先天抗病毒免疫基因、聚糖代谢的转运蛋白和酶。肝脏中的转录组反应表明，缺乏虾青素对脂质代谢有影响，尤其是对萜类和类固醇生物合成增加有影响，而对免疫基因影响较小。在缺乏虾青素的情况下，骨骼肌中观察到最大的转录组变化，免疫相关基因（119个）上调，还有多个与应激有明确关联的基因。这种情况类似于肌肉的轻度炎症。基因表达变化的小规模或中等规模与两种日粮喂养的鱼相同的生长性能一致，但它们的特征可能表明日粮中缺乏类胡萝卜素存在潜在风险。
