Project description:The aim of the present study was to generate an experimental model to characterize the nutrigenomic profile of a plant-derived nutritional stress (S30 = 300 g Kg-1 Soybean Meal). Our results provided: a) a snapshot of molecular signatures describing a chronic and advanced nutritional stress to which future nutrigenomic studies might refer to; and b) a platform for the identification of candidate genes for the molecular phenotyping of several physiological parameters in liver and distal intestine. Atlantic salmon was used as a model. The nutritional stress was induced by inclusions of dietary defatted soybean meal (SBM) up to a level of 300 g kg-1, being this ingredient extensively demonstrated to induce reduced performance and enteropathy in the distal intestine (Baeverfjord and Krogdahl, 1996;Urán et al., 2009;URÁN et al., 2008). A control treatment with no SBM (S0) as well as intermediate levels of inclusion (100 g kg-1 and 200 g kg-1 SBM) were included to span a range of optimal and sub-optimal conditions. Performance parameters were measured and impaired growth was taken as an indicator of pronounced and chronic nutritional stress. Molecular analyses were performed in two tissues, liver and distal intestine. Distal intestine was chosen for being the site most morphologically and physiologically affected during the development of intestinal pathologies associated with plant ingredients such as SBM (Baeverfjord and Krogdahl, 1996;Kortner et al., 2011), while liver for being arguably the most metabolic active tissue. These tissues have been the most investigated targets in nutritional studies on fish so far. To the best of our knowledge, this study is the most comprehensive of its kind to report on the transcriptomic profile of the distal intestine and the liver, hence highlighting the supporting role of this tissue, in fish undergoing SBM-induced nutritional stress. Skugor et al (, 2011) described gene expression profiles of liver and intestine in fish fed 200 g kg-1 SBM inclusion using a 11K trout array. By investigating a larger number of probes (44K) in a more severe nutritional stress (300 g kg-1), our work will add further nutrigenomic information to the current literature.
Project description:The present work characterizes the response of co-habited Atlantic (Salmo salar), chum (Oncorhynchus keta) and pink salmon (Oncorhynchus gorbuscha) to sea lice infections. Atlantic and pink salmon anterior kidney samples were profiled at three time points over nine days after the start of an experimental infection. Chum salmon anterior kidney was profiled at day six post infection only. All three species were also profiled at six days post exposure for skin responses of the pectoral fin, typically associated with lice infection.
Project description:Dietary soyasaponin supplementation to pea protein concentrate reveals nutrigenomic interactions underlying enteropathy in Atlantic salmon
Project description:Piscine reovirus (PRV) is a causative agent of heart and skeletal muscle inflammation in Atlantic salmon, which is propagated in red blood cells (RBC). Here, transcriptome analyses of PRV infected erythrocytes showed strong and complex innate antiviral responses.
Project description:This study was performed to investigate assess the impacts of CO and/or CM containing diets on Atlantic salmon hepatic gene expression in order to identify candidate molecular biomarkers of responses to camelina-containing diets. Atlantic salmon were fed diets with complete or partial replacement of FO and/or FM with camelina oil (CO) and/or camelina meal (CM) in a 16-week trial (Control diet: FO; Test diet: 100% FO replacement with CO, with solvent-extracted FM and inclusion of 10% CM (100COSEFM10CM). A 44K microarray experiment identified liver transcripts that responded to 100COSEFM10CM (associated with reduced growth) compared to FO controls at week 16.
Project description:Atlantic salmon (Salmo salar L.) is an environmentally and economically important organism and its gene content is reasonably well characterized. From a transcriptional standpoint, it is important to characterize the normal changes in gene expression over the course of early development, from fertilization through to the parr stage.S. salar samples were taken at 17 time points from 2 to 89 days post fertilization. Total RNA was extracted and cRNA was synthesized and hybridized to a new 44K oligo salmonid microarray platform. Quantified results were subjected to preliminary data analysis and submitted to NCBI’s Gene Expression Omnibus. Throughout the entire period of development, several thousand genes were found to be differentially regulated. This work represents the trancriptional characterization of a very large geneset that will be extremely valuable in further examination of the transcriptional changes in Atlantic salmon during the first few months of development. The expression profiles can help to annotate salmon genes in addition to being used as references against any number of experimental variables that developing salmonids might be subjected to.
Project description:Atlantic salmon can synthesize polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (20:5n-3), arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) via activities of very long chain fatty acyl elongases (elovls) and fatty acyl desaturases (fads), albeit to a limited degree. Understanding molecular mechanisms of PUFA biosynthesis and regulation is a pre-requisite for sustainable use of vegetable oils in aquafeeds as current sources of fish oils are unable to meet increasing demands for omega-3 PUFAs. By generating CRISPR-mediated elovl2 knockout, we have shown that elovl2 is crucial for multi-tissue synthesis of 22:6n-3 in vivo and endogenously synthesized PUFAs are important for transcriptional regulation of lipogenic genes in Atlantic salmon. The elovl2 knockouts showed reduced levels of 22:6n-3 and accumulation of 20:5n-3 and docosapentaenoic acid (22:5n-3) in the liver, brain and white muscle, suggesting inhibition of elongation. Additionally, elovl2-knockout salmon showed accumulation of 20:4n-6 in the brain and white muscle. The impaired synthesis of 22:6n-3 induced hepatic expression of sterol regulatory element binding protein-1 (srebp-1), fatty acid synthase-b, Δ6fad-a, Δ5fad and elovl5. Our study demonstrates key roles of elovl2 at two penultimate steps of PUFA synthesis in vivo and suggests Srebp-1 as a main regulator of PUFA synthesis in Atlantic salmon.