Tissue distribution of Peroxisome proliferator-activated receptors in salmon fish (Salmo salar L.)

Peroxisome Proliferator-activated Receptors (PPARs) are ligand-inducible transcription factors, that can be activated by both dietary fatty acids and their metabolic derivates in the body, as by eicosanoids, hypolipidemic agents or antidiabetic drugs. To date three PPAR isotypes have been identified in mammals, birds, and amphibians, termed PPARα, PPARγ, and PPARβ/δ. Each isotype is a product of a separate gene and each one has a distinct tissue distribution . The importance of this receptors is nowadays a focus on different stu-dies, due to medical and pharmacological interest, most studies on PPARs have concen-trated on mammalian genes and proteins but also some research has also been done on fish. This recent interests on fish is due to the fact that aquaculture production is increasing and it's being a challenge feeding fish using fish oil, trying to replace it with vegetable oil. Changing the dietary pattern influences the fatty acid composition in fish tissues with the decrease of the n-3 highly unsaturated fatty acids, as main consequence rendering fish less beneficial for human health. One way to find new approaches for using vegetable oil or other ways to feed farmed fish, is to study changes on gene expression, or on receptors that affect lipid's genome and one of those are PPARs. The main objective of this study is to learn about PPAR, focusing on the tissue distribu-tion of his different isotypes, and associate it with their functions on the organism. While studying the PCR methodology in order to know the gene expression of each PPAR