Cloning, Functional Characterization and Nutritional Regulation of Δ6 Fatty Acyl Desaturase in the Herbivorous Euryhaline Teleost Scatophagus Argus

Marine fish are generally unable or have low ability for the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA) from C18 PUFA precursors, with some notable exceptions including the herbivorous marine teleost Siganus canaliculatus in which such a capability was recently demonstrated. To determine whether this is a unique feature of S. canaliculatus or whether it is common to the herbivorous marine teleosts, LC-PUFA biosynthetic pathways were investigated in the herbivorous euryhaline Scatophagus argus. A putative desaturase gene was cloned and functionally characterized, and tissue expression and nutritional regulation were investigated. The full-length cDNA was 1972 bp, containing a 1338 bp open-reading frame encoding a polypeptide of 445 amino acids, which possessed all the characteristic features of fatty acyl desaturase (Fad). Functional characterization by heterologous expression in yeast showed the protein product of the cDNA efficiently converted 18:3n-3 and 18:2n-6 to 18:4n-3 and 18:3n-6, respectively, indicating Δ6 desaturation activity. Quantitative real-time PCR showed that highest Δ6 fad mRNA expression was detected in liver followed by brain, with lower expression in other tissues including intestine, eye, muscle, adipose, heart kidney and gill, and lowest expression in stomach and spleen. The expression of Δ6 fad was significantly affected by dietary lipid and, especially, fatty acid composition, with highest expression of mRNA in liver of fish fed a diet with a ratio of 18:3n-3/18:2n-6 of 1.72:1. The results indicated that S. argus may have a different LC-PUFA biosynthetic system from S. canaliculatus despite possessing similar habitats and feeding habits suggesting that LC-PUFA biosynthesis may not be common to all marine herbivorous teleosts.

[1]  Ó. Monroig,et al.  Functional characterisation of a Fads2 fatty acyl desaturase with Δ6/Δ8 activity and an Elovl5 with C16, C18 and C20 elongase activity in the anadromous teleost meagre (Argyrosomus regius) , 2013 .

[2]  S. Boonanuntanasarn,et al.  Characterization of fatty acid delta-6 desaturase gene in Nile tilapia and heterogenous expression in Saccharomyces cerevisiae. , 2013, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[3]  H. Ren,et al.  Two Δ6-desaturase-like genes in common carp (Cyprinus carpio var. Jian): structure characterization, mRNA expression, temperature and nutritional regulation. , 2013, Gene.

[4]  J. Sunyer,et al.  Fatty-acid composition of maternal and umbilical cord plasma and early childhood atopic eczema in a Spanish cohort , 2013, European Journal of Clinical Nutrition.

[5]  M. Lagarde,et al.  n-3 PUFA added to high-fat diets affect differently adiposity and inflammation when carried by phospholipids or triacylglycerols in mice , 2013, Nutrition & Metabolism.

[6]  G. Ailhaud,et al.  Omega-6 polyunsaturated fatty acids and the early origins of obesity , 2013, Current opinion in endocrinology, diabetes, and obesity.

[7]  A. Bakillah,et al.  Nutrition & Metabolism: an impressive performance since inception , 2013, Nutrition & Metabolism.

[8]  Katherine E Halliday,et al.  Long-chain PUFA supplementation in rural African infants: a randomized controlled trial of effects on gut integrity, growth, and cognitive development123 , 2012, The American journal of clinical nutrition.

[9]  H. Ren,et al.  Influence of dietary fatty acids on muscle fatty acid composition and expression levels of Δ6 desaturase-like and Elovl5-like elongase in common carp (Cyprinus carpio var. Jian). , 2012, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[10]  Yuanyou Li,et al.  Effects of replacement of dietary fish oil with soybean oil on growth performance and tissue fatty acid composition in marine herbivorous teleost Siganus canaliculatus , 2012 .

[11]  Ó. Monroig,et al.  Elongation of long-chain fatty acids in rabbitfish Siganus canaliculatus: Cloning, functional characterisation and tissue distribution of Elovl5- and Elovl4-like elongases , 2012 .

[12]  Ó. Monroig,et al.  Functional Desaturase Fads1 (Δ5) and Fads2 (Δ6) Orthologues Evolved before the Origin of Jawed Vertebrates , 2012, PloS one.

[13]  Ó. Monroig,et al.  Monroig O, Wang S, Zhang L, You C, Tocher DR & Li Y (2012) Elongation of long-chain fatty acids in rabbitfish Siganus canaliculatus: Cloning, functional characterisation and tissue distribution of Elovl5- and Elovl4-like elongases, Aquaculture, , 2012 .

[14]  A. C. Shu-Chien,et al.  Molecular cloning and ontogenic mRNA expression of fatty acid desaturase in the carnivorous striped snakehead fish (Channa striata). , 2011, Comparative biochemistry and physiology. Part A, Molecular & integrative physiology.

[15]  D. Tocher,et al.  Expression of fatty acyl desaturase and elongase genes, and evolution of DHA:EPA ratio during development of unfed larvae of Atlantic bluefin tuna (Thunnus thynnus L.) , 2011 .

[16]  H. U. Kim,et al.  Functional characterization of a delta 6-desaturase gene from the black seabream (Acanthopagrus schlegeli) , 2011, Biotechnology Letters.

[17]  Ó. Monroig,et al.  Long-chain polyunsaturated fatty acids in fish: recent advances on desaturases and elongases involved in their biosynthesis , 2011 .

[18]  L. Corcos,et al.  Cloning, Tissue Expression Analysis, and Functional Characterization of Two Δ6-Desaturase Variants of Sea Bass (Dicentrarchus labrax L.) , 2011, Marine Biotechnology.

[19]  Ó. Monroig,et al.  Vertebrate fatty acyl desaturase with Δ4 activity , 2010, Proceedings of the National Academy of Sciences.

[20]  Ó. Monroig,et al.  Multiple genes for functional 6 fatty acyl desaturases (Fad) in Atlantic salmon (Salmo salar L.): gene and cDNA characterization, functional expression, tissue distribution and nutritional regulation. , 2010, Biochimica et biophysica acta.

[21]  D. Tocher,et al.  Fish oil replacement and alternative lipid sources in aquaculture feeds , 2010 .

[22]  K. Wan,et al.  Investigation of highly unsaturated fatty acid metabolism in the Asian sea bass, Lates calcarifer , 2010, Fish Physiology and Biochemistry.

[23]  D. Tocher.  Fatty acid requirements in ontogeny of marine and freshwater fish , 2010 .

[24]  Alimuddin,et al.  Cloning and nutritional regulation of polyunsaturated fatty acid desaturase and elongase of a marine teleost, the nibe croaker Nibea mitsukurii , 2010, Fisheries Science.

[25]  D. Tocher,et al.  The effects of fish oil replacement on lipid metabolism of fish , 2010 .

[26]  D. Tocher,et al.  Molecular and functional characterization and expression analysis of a Δ6 fatty acyl desaturase cDNA of European Sea Bass (Dicentrarchus labrax L.). , 2009 .

[27]  Ó. Monroig,et al.  Physiological roles of fatty acyl desaturases and elongases in marine fish: Characterisation of cDNAs of fatty acyl Δ6 desaturase and elovl5 elongase of cobia (Rachycentron canadum) , 2009 .

[28]  D. Tocher,et al.  Ontogenic effects of early feeding of sea bass (Dicentrarchus labrax) larvae with a range of dietary n-3 highly unsaturated fatty acid levels on the functioning of polyunsaturated fatty acid desaturation pathways. , 2009, The British journal of nutrition.

[29]  Ó. Monroig,et al.  Highly Unsaturated Fatty Acid Synthesis in Atlantic Salmon: Characterization of ELOVL5- and ELOVL2-like Elongases , 2009, Marine Biotechnology.

[30]  P. Kestemont,et al.  Influence of different dietary 18:3n-3/18:2n-6 ratio on growth performance, fatty acid composition and hepatic ultrastructure in Eurasian perch, Perca fluviatilis , 2008 .

[31]  Yuanyou Li,et al.  The effects of dietary fatty acids on liver fatty acid composition and Delta(6)-desaturase expression differ with ambient salinities in Siganus canaliculatus. , 2008, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[32]  C. Hernández‐Cruz,et al.  Regulation of growth, fatty acid composition and delta 6 desaturase expression by dietary lipids in gilthead seabream larvae (Sparus aurata) , 2008, Fish Physiology and Biochemistry.

[33]  U. Jung,et al.  n-3 Fatty acids and cardiovascular disease: actions and molecular mechanisms. , 2007, Prostaglandins, leukotrienes, and essential fatty acids.

[34]  C. Transler,et al.  Effects of n-3 long chain polyunsaturated fatty acid supplementation on visual and cognitive development throughout childhood: a review of human studies. , 2007, Prostaglandins, leukotrienes, and essential fatty acids.

[35]  G. Turchini,et al.  Dietary lipid source modulates in vivo fatty acid metabolism in the freshwater fish, Murray cod (Maccullochella peelii peelii). , 2007, Journal of agricultural and food chemistry.

[36]  D. Tocher,et al.  Highly unsaturated fatty acid synthesis in marine fish: Cloning, functional characterization, and nutritional regulation of fatty acyl Δ6 desaturase of Atlantic cod (Gadus morhua L.) , 2006, Lipids.

[37]  J. G. Bell,et al.  Nutritional and environmental regulation of the synthesis of highly unsaturated fatty acids and of fatty-acid oxidation in Atlantic salmon (Salmo salar L.) enterocytes and hepatocytes , 2006, Fish Physiology and Biochemistry.

[38]  A. Geelen,et al.  n-3 Fatty acids, cardiac arrhythmia and fatal coronary heart disease. , 2006, Progress in lipid research.

[39]  D. Tocher,et al.  Influence of dietary oil content and conjugated linoleic acid (CLA) on lipid metabolism enzyme activities and gene expression in tissues of atlantic salmon (Salmo salar L.) , 2006, Lipids.

[40]  J. G. Bell,et al.  Environmental and dietary influences on highly unsaturated fatty acid biosynthesis and expression of fatty acyl desaturase and elongase genes in liver of Atlantic salmon (Salmo salar). , 2005, Biochimica et biophysica acta.

[41]  J. G. Bell,et al.  Highly unsaturated fatty acid synthesis in vertebrates: New insights with the cloning and characterization of a Δ6 desaturase of Atlantic salmon , 2005, Lipids.

[42]  Alimuddin,et al.  Enhancement of EPA and DHA biosynthesis by over-expression of masu salmon Δ6-desaturase-like gene in zebrafish , 2005, Transgenic Research.

[43]  D. Tocher,et al.  Molecular Cloning and Functional Characterization of Fatty Acyl Desaturase and Elongase cDNAs Involved in the Production of Eicosapentaenoic and Docosahexaenoic Acids from α-Linolenic Acid in Atlantic Salmon (Salmo salar) , 2004, Marine Biotechnology.

[44]  D. Tocher,et al.  Characterization and comparison of fatty acyl Delta6 desaturase cDNAs from freshwater and marine teleost fish species. , 2004, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[45]  S. Berry.  Lipid Analysis: Isolation, Separation, Identification and Structural Analysis of Lipids , 2004 .

[46]  B. Ruyter,et al.  Influence of dietary n-3 fatty acids on the desaturation and elongation of [1-14C] 18:2 n-6 and [1-14C] 18:3 n-3 in Atlantic salmon hepatocytes , 2000, Fish Physiology and Biochemistry.

[47]  S. Panserat,et al.  Cloning and nutritional regulation of a Delta6-desaturase-like enzyme in the marine teleost gilthead seabream (Sparus aurata). , 2003, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[48]  M. Whelan,et al.  A method for the absolute quantification of cDNA using real-time PCR. , 2003, Journal of immunological methods.

[49]  J. G. Bell,et al.  Effects of dietary vegetable oil on atlantic salmon hepatocyte fatty acid desaturation and liver fatty acid compositions , 2003, Lipids.

[50]  J. G. Bell,et al.  Substituting fish oil with crude palm oil in the diet of Atlantic salmon (Salmo salar) affects muscle fatty acid composition and hepatic fatty acid metabolism. , 2002, The Journal of nutrition.

[51]  V. Gandhi.  Studies on the food and feeding habits of cultivable butterfish Scatophagus argus (Cuv. and Val.) , 2002 .

[52]  D. Tocher,et al.  A vertebrate fatty acid desaturase with Δ5 and Δ6 activities , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[53]  J. Dick,et al.  Biosynthesis and tissue deposition of docosahexaenoic acid (22∶6n−3) in rainbow trout (Oncorhynchus mykiss) , 2001, Lipids.

[54]  J. G. Bell,et al.  Hepatocyte fatty acid desaturation and polyunsaturated fatty acid composition of liver in salmonids: effects of dietary vegetable oil. , 2001, Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology.

[55]  J. G. Bell,et al.  Replacement of fish oil with rapeseed oil in diets of Atlantic salmon (Salmo salar) affects tissue lipid compositions and hepatocyte fatty acid metabolism. , 2001, The Journal of nutrition.

[56]  J. G. Bell,et al.  The effect of dietary lipid on polyunsaturated fatty acid metabolism in Atlantic salmon (Salmo salar) undergoing parr-smolt transformation , 1997, Lipids.

[57]  J. G. Bell,et al.  Dietary sunflower, linseed and fish oils affect phospholipid fatty acid composition, development of cardiac lesions, phospholipase activity and eicosanoid production in Atlantic salmon (Salmo salar). , 1993, Prostaglandins, leukotrienes, and essential fatty acids.

[58]  A. Fast,et al.  Biology of the Spotted Scat (Scatophagus argus) in the Philippines , 1992, Asian Fisheries Science.

[59]  Desmond G. Higgins,et al.  Fast and sensitive multiple sequence alignments on a microcomputer , 1989, Comput. Appl. Biosci..

[60]  N. Saitou,et al.  The neighbor-joining method: a new method for reconstructing phylogenetic trees. , 1987, Molecular biology and evolution.

[61]  R. R. Brenner,et al.  Early effects of EFA deficiency on the structure and enzymatic activity of rat liver microsomes. , 1981, Progress in lipid research.

[62]  J. Folch,et al.  A simple method for the isolation and purification of total lipides from animal tissues. , 1957, The Journal of biological chemistry.