title: Modification of the n-3 HUFA biosynthetic pathway by transgenesis in a marine teleost, nibe croaker.
abstract: Marine fishes are generally unable to produce sufficient quantities of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) for their normal growth and survival, as the key fatty acid-metabolizing enzymes in the EPA and DHA biosynthetic pathway are limited. It is therefore necessary to supplement cultured marine fish species diets with fish oils in order to supply EPA and DHA. Given that freshwater fishes are capable of synthesizing both EPA and DHA, they presumably express all of the enzymes required for this biosynthetic pathway. Thus, we hypothesize that transgenic marine species carrying these fatty acid-metabolizing enzymes could be reared without the dietary supplementation of fish oil. As the first step toward this goal, we used marine fish, nibe croaker to produce a transgenic line carrying the elongase gene isolated from masu salmon. Fatty acid analysis revealed that the liver EPA (20:5n-3) content in the transgenic fish was lower (3.3% vs. 7.7%). However, docosapentaenoic acid (22:5n-3) content in the transgenic fish was 2.28-fold (4.1% vs. 1.8%) higher than in non-transgenic fish. Further, tetracosapentaenoic acid (24:5n-3) was specifically detected in the transgenic fish. We therefore conclude that the development of transgenic fish lines with these fatty acid-metabolizing enzymes could be a powerful tool for manipulating fatty acid metabolic pathways in fish.
authors.affiliation: Research Fellow of the Japan Society for the Promotion of Science, 1-8 Ichiban-cho, Chiyoda-ku, Tokyo 102-8472, Japan; Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kabeya
authors.affiliation: Research Center for Advanced Science and Technology, Tokyo University of Marine Science and Technology, Banda 670, Tateyama-shi, Chiba 294-0308, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takeuchi
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Yazawa
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Haga
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Satoh
authors.affiliation: Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan. Electronic address: goro@kaiyodai.ac.jp.
authors.forename: Goro
authors.initials: G
authors.lastname: Yoshizaki
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D053898:Biosynthetic Pathways; D003001:Cloning, Molecular; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D015118:Eicosapentaenoic Acid / Q000378:metabolism*; D000081031:Fatty Acid Elongases; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D010473:Perciformes / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D012474:Salmon / Q000235:genetics / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D029941:Fish Proteins; D004281:Docosahexaenoic Acids; C099830:tetracosapentaenoic acid; D015118:Eicosapentaenoic Acid; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases; C026219:docosapentaenoic acid
keywords: Croaker; DHA; EPA; Elongase; Transgenic