title: Cloning and expression characterization of peroxisome proliferator-activated receptors (PPARs) with their agonists, dietary lipids, and ambient salinity in rabbitfish Siganus canaliculatus.
abstract: Rabbitfish Siganus canaliculatus is the first marine teleost reported to have the ability of biosynthesizing C20-22long-chain polyunsaturated fatty acids (LC-PUFA) from C18precursors, and thus provides a model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. To investigate the possible roles of peroxisome proliferator-activated receptors (PPARs), critical transcription factors involved in the regulation of lipid metabolism, in the regulation of LC-PUFA biosynthesis in rabbitfish, the PPAR genes were cloned and their expression characterization with PPAR agonists, dietary lipid resource, and ambient salinity were examined. Three cDNA sequences respectively encoding 477, 516 and 519 amino acids of PPARα, PPARβ, and PPARγ isoforms were obtained. PPARα exhibited a wide tissue expression with its highest levels in the heart and brain; PPARβ was predominantly expressed in the gills, while PPARγ was highly expressed in the intestine and gills. In rabbitfish primary hepatocytes, both the PPAR agonists 2-bromopalmitate (2-Bro) and fenofibrate (FF) increased the expression of PPARγ, SREBP1c and Elovl5, whereas FF depressed the expression of Δ6/Δ5 Fad. Moreover, a higher hepatic PPARβ expression was observed in fish fed diets with vegetable oils (VO) than that with fish oil (FO), in the former the expression of PPARα, PPARβ, and PPARγ were increased at the low ambient salinity (10ppt), where an increasing expression of Δ5/Δ6 Fad, Δ4 Fad and Elovl5 genes was previously reported. These results suggest that PPARs might be involved in the upregulation of LC-PUFA biosynthesis with dietary VO and low ambient salinity in rabbitfish.
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Cuihong
authors.initials: C
authors.lastname: You
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Danli
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Qinghao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Dizhi
authors.initials: D
authors.lastname: Xie
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China.
authors.forename: Yewei
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, Guangdong 515063, China; College of Marine Science, South China Agricultural University, Guangzhou, Guangdong 510642, China. Electronic address: yyli2004@21cn.com.
authors.forename: Yuanyou
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004032:Diet / Q000662:veterinary; D004041:Dietary Fats / Q000494:pharmacology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D010473:Perciformes; D047492:Peroxisome Proliferator-Activated Receptors / Q000819:agonists* / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D054712:Salinity
chemical_list: D004041:Dietary Fats; D047492:Peroxisome Proliferator-Activated Receptors
keywords: Agonist; Ambient salinity; Dietary lipid resource; LC-PUFA biosynthesis; PPARs; Siganus canaliculatus