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Add To Calendar 22/02/2017 14:00:0022/02/2017 14:20:00America/ChicagoAquaculture America 2017TRANSCRIPTOMIC STUDIES OF LIPID METABOLISM IN DIFFERENT INTESTINAL SECTION OF SALMON FRY FED VEGETABLE OIL Salon DThe World Aquaculture Societyjohnc@was.orgfalseanrl65yqlzh3g1q0dme13067DD/MM/YYYY


Jin, Y.*, Olsen, R.E., Østensen, M.A., Gillard, G. , Korsvoll, S.A., Santi, N., Gjuvsland, A.B. , Vik, J.O. , Torgersen, J.S. , Sandve, S.R.2, Olsen, Y.
Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway,

The aim of this study was to understand the transcriptomic development of lipid metabolism in salmon fry fed fish oil (FO) or vegetable oil (VO). RNA-seq was done on stomach (SM), pyloric caeca (PC) and hindgut (HG) of 0.16g salmon (before first feeding), and of 2.5g and 10g salmon fed FO or VO diets. We compared expression of duplicated homolog genes involved in biosynthetic pathways of several lipid classes such as phospholipid (PL), fatty acids (FA) and cholesterol (CH) between diets, tissues and developmental stages.

Gene duplicates can have very different expression levels between diets, tissues and developmental stages. The diverged expression of pcyt1 duplicates was a representative example (Figure 1). The pcyt1ab_1 and pcyt1ab_2 duplicates were expressed higher than the two others in SM, while pcyt1bb_1 was the highest expressed duplicate in MG and HG. Dietary inclusion of VO reduced the expression of pcyt1bb_1, while other duplicates were not influenced as much. Like pcyt1 duplicates, we found in most cases one or two gene duplicates had much higher expression than others in each tissue, suggesting these genes to be the key regulators in the pathways. Moreover, the key regulatory genes in PC were mostly expressed higher than the regulators in SM and HG, proving the former to be more important for lipid biosynthesis.

By analyzing the key regulatory genes, we found up-regulation of biosynthetic pathways of phosphatidylcholine, phosphatidylethanolamine, cholesterol and fatty acids during development, while the biosynthesis of other lipid classes was not changed. CH biosynthetic pathway was the most significantly (FDR < 0.05) changed pathway influenced by diet. Almost all regulatory genes in CM biosynthetic pathway were significantly (FDR < 0.05) up-regulated in PC of VO-fed salmon. In relation to lipid transport, lipoprotein formation pathway was also up-regulated in VO-fed salmon. Similar changes of lipid pathways were also identified in HG, though the overall expression levels were much lower in the tissue. The lipid metabolic pathways in SM were mostly unchanged between diets and development.

(Summary of duplicates and pathways will be shown in other figures)

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