Nutrigenomic profiling of transcriptional processes affected in liver and distal intestine in response to a soybean meal-induced nutritional stress in Atlantic salmon (Salmo salar)

Abstract

The aim of the present study was to generate an experimental model to characterize the nutrigenomic profile of a plant-derived nutritional stress. Atlantic salmon (Salmo salar) was used as the model species and the nutritional stress was induced by inclusion of dietary defatted soybean meal (SBM), as this ingredient had been previously demonstrated to induce enteropathy in the distal intestine and reduced growth performance in salmon. Triplicate groups of Atlantic salmon were fed increasing concentrations (0, 100, 200 and 300 g kg-1) of SBM for 12 weeks and reduced growth performance was used as the indicator of nutritional stress. The transcriptome was analysed in two tissues, distal intestine and liver, with the hypothesis being that intestinal gene expression would be dominated by specific responses to SBM whereas the liver transcriptome would include gene expression responses that could be more general and related to overall performance. Specifically, a set of 133 genes was differentially expressed in liver including 45 genes in common with the intestinal response. The liver specific response included genes involved in protein digestion and energy metabolism that were up-regulated, whereas genes in other pathways were generally anabolic and down-regulated. These responses may be more related to general nutritional stress than to SBM per se. This study provides a comprehensive report on the profiles of distal intestine and liver transcriptomes, highlighting the role of the latter tissue in fish undergoing SBM-induced nutritional stress.