"There is an urgent need to replace fish oil (FO) and meal in aquaculture diets with sustainable alternatives, vegetable oils (VO) being the primary candidates. However, growth of fish on VO results in lower levels of n-3HUFA in their flesh, compromising their nutritional value to the human consumer. There is therefore a pressing need to identify strains of fish with reduced requirements for pre-formed dietary n-3HUFA. The intestine is the gateway of nutrients into the body and the enterocyte intracellular metabolic activity is much more important than initially thought. However, very little information exists on how the physiological functions of the intestine are affected by different dietary lipids. Additionally, the inclusion of VO in the diet of carnivorous fish commonly results in histological changes in the intestine. Identification of the genes and pathways involved in PUFA metabolism in salmon intestinal tissue is of direct relevance to these problems. This project will address this issue by the identification of salmon genes and metabolic pathways in intestinal tissue influencing traits that are important in terms of sustainability of farm production and nutritional quality for the consumer. The project will apply cutting edge molecular techniques for the analyses of fish transcriptomes (microarrays) and proteomes (proteomics), to determine differential expression patterns in intestine of salmon fed FO and VO and how they may be affected by genotype (fatty or lean families). Bioinformatic analyses will enable key pathways, genes and enzymes/proteins to be identified. The project is a groundbreaking example of an interdisciplinary approach combining traditional nutritional and biochemical studies with modern molecular analyses to address a problem which is not only of scientific interest but also of critical importance to the future development and continuing expansion of aquaculture and the delivery of safe and nutritious seafood for the people of the EU."