Differential gene expression after total replacement of dietary fish meal and fish oil by plant products in rainbow trout (Oncorhynchus mykiss) liver

Abstract

Our objective was to analyse the hepatic transcriptomes of juvenile rainbow trout fed with a plantbased diet. We focused our analysis on the total replacement of fish meal (FM) and fish oil (FO) by a 100% plant-based diet (0% FM, 0% FO). We analysed the postprandial hepatic transcriptomes of rainbow trout fed the two diets 8 h after feeding. Six total hepatic RNAs from each dietary group were hybridised against a trout cDNA microarray (9K). After treatment of the data respecting the standard MIAME (Minimum Information About a Microarray Experiment) protocol, we found that 176 hepatic genes were differentially expressed between fish fed the two diets: 96 and 80 were over-expressed and under-expressed, respectively, in trout fed the plant-based diet. A large majority of differentially expressed genes were involved in metabolism (57%) and the others in cellular processes (21%) and transport (10%). Among the genes involved in metabolism (n = 86), 37% were associated with protein metabolism (proteolysis, amino acid catabolism), 21% with lipid metabolism (fatty acid biosynthesis, cholesterol biosynthesis), 30% with nucleic acid metabolism and 8% with glucose metabolism. Specifically, we found in rainbow trout fed the 100% plant diet an over-expression of genes involved in lipid biosynthesis (cholesterol metabolism and desaturation of polyunsaturated fatty acids) and an over-expression of a new metabolic actor, i.e., glycerol kinase which plays a key role at the interface of glucose-lipid metabolism. Overall, these data demonstrate that a number of intermediary metabolic effects occur in trout fed a totally plant-based diet.

An initial investigation replacing fish meal with a commercial fermented soybean meal product in the diets of juvenile rainbow trout

“…The observed hepatosomatic index of 0.98 to 1.07 in rainbow trout fed diets containing up to 30% PSG is similar to that reported by Barrows et al [53] and Panserat et al [65] for rainbow trout fed fish meal or other plant-based diets. However, these values are much lower than those from other studies which fed soybean meal or other soybean products [48,50,52,53].…”

Effect of partial fish meal replacement by soybean meal on the growth performance and biochemical indices of juvenile Japanese flounder Paralichthys olivaceus

“…Recent results showed that the HSI increase was accompanied by elevated liver lipid content in fish fed higher plant protein diets (Sitjà-Bobadilla et al 2005;de Francesco et al 2007;Kjaer et al 2009). Panserat et al (2009) observed an over-expression of genes involved in liver lipid biosynthesis (CHO metabolism and desaturation of polyunsaturated fatty acids) in rainbow trout fed the 100% plant diet (versus the FM-based diet). In addition, liver lipid was also positively correlated with serum TG and negatively correlated with HDL-C (Kotronen and Yki-Järvinen 2008).…”

A nutrigenomic analysis of intestinal response to partial soybean meal replacement in diets for juvenile Atlantic halibut, Hippoglossus hippoglossus, L.

“…Nutrigenomics, by providing global gene expression patterns under different dietary conditions, can provide an improved understanding of how overall nutrition or the inclusion of specific dietary ingredients influences metabolic pathways and, potentially, animal performance. This approach has been successfully used to investigate changes in gene expression in Atlantic salmon liver resulting from partial replacement of fish oil with vegetable oil (Jordal et al, 2005;Leaver et al, 2008) and growth hormone transgenesis (Rise et al, 2006), in rainbow trout liver after varying dietary fish oil levels (Panserat et al, 2008) or total replacement of fish protein and oil with vegetable products (Panserat et al, 2009), and in intestine of rainbow trout deficient in phosphorus (Kirchner et al, 2007). We now have identified genes that are differentially regulated in Atlantic halibut in response to replacement of FM with SBM.…”