title: Diet × genotype interactions in hepatic cholesterol and lipoprotein metabolism in Atlantic salmon (Salmo salar) in response to replacement of dietary fish oil with vegetable oil.
abstract: The present study investigates the effects of genotype on responses to alternative feeds in Atlantic salmon. Microarray analysis of the liver transcriptome of two family groups, lean or fat, fed a diet containing either a fish oil (FO) or a vegetable oil (VO) blend indicated that pathways of cholesterol and lipoprotein metabolism might be differentially affected by the diet depending on the genetic background of the fish, and this was further investigated by real-time quantitative PCR, plasma and lipoprotein biochemical analysis. Results indicate a reduction in VLDL and LDL levels, with no changes in HDL, when FO is replaced by VO in the lean family group, whereas in fat fish fed FO, levels of apoB-containing lipoproteins were low and comparable with those fed VO in both family groups. Significantly lower levels of plasma TAG and LDL-TAG were measured in the fat group that was independent of diet, whereas plasma cholesterol was significantly higher in fish fed the FO diet in both groups. Hepatic expression of genes involved in cholesterol homeostasis, β-oxidation and lipoprotein metabolism showed relatively subtle changes. A significantly lower expression of genes considered anti-atherogenic in mammals (ATP-binding cassette transporter A1, apoAI, scavenger receptor class B type 1, lipoprotein lipase (LPL)b (TC67836) and LPLc (TC84899)) was found in lean fish, compared with fat fish, when fed VO. Furthermore, the lean family group appeared to show a greater response to diet composition in the cholesterol biosynthesis pathway, mediated by sterol-responsive element-binding protein 2. Finally, the presence of three different transcripts for LPL, with differential patterns of nutritional regulation, was demonstrated.
authors: Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, UK. sofia.morais@stir.ac.uk
authors: Sofia
authors: S
authors: Morais
authors: Jarunan
authors: J
authors: Pratoomyot
authors: Bente E
authors: BE
authors: Torstensen
authors: John B
authors: JB
authors: Taggart
authors: Derrick R
authors: DR
authors: Guy
authors: J Gordon
authors: JG
authors: Bell
authors: Douglas R
authors: DR
authors: Tocher
mesh_terms: D000818:Animals; D001483:Base Sequence; D002784:Cholesterol / Q000378:metabolism*; D017931:DNA Primers; D004032:Diet; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D005395:Fish Oils / Q000008:administration & dosage*; D020869:Gene Expression Profiling; D005838:Genotype; D008074:Lipoproteins / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D010938:Plant Oils / Q000008:administration & dosage*; D060888:Real-Time Polymerase Chain Reaction; D020317:Salmo salar
chemical_list: D017931:DNA Primers; D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D008074:Lipoproteins; D010938:Plant Oils; D002784:Cholesterol