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Ramos-Llorens M, Hontoria F, Navarro JC, Ferrier DEK, Monroig Ó. Functionally diverse front-end desaturases are widespread in the phylum Annelida. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159377. [PMID: 37517549 DOI: 10.1016/j.bbalip.2023.159377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/24/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
Aquatic single-cell organisms have long been believed to be unique primary producers of omega-3 long-chain (≥C20) polyunsaturated fatty acids (ω3 LC-PUFA). Multiple invertebrates including annelids have been discovered to possess methyl-end desaturases enabling key steps in the de novo synthesis of ω3 LC-PUFA, and thus potentially contributing to their production in the ocean. Along methyl-end desaturases, the repertoire and function of further LC-PUFA biosynthesising enzymes is largely missing in Annelida. In this study we examined the front-end desaturase gene repertoire across the phylum Annelida, from Polychaeta and Clitellata, major classes of annelids comprising most annelid diversity. We further characterised the functions of the encoded enzymes in selected representative species by using a heterologous expression system based in yeast, demonstrating that functions of Annelida front-end desaturases have highly diversified during their expansion in both terrestrial and aquatic ecosystems. We concluded that annelids possess at least two front-end desaturases with Δ5 and Δ6Δ8 desaturase regioselectivities, enabling all the desaturation reactions required to convert the C18 precursors into the physiologically relevant LC-PUFA such as eicosapentaenoic and arachidonic acids, but not docosahexaenoic acid. Such a gene complement is conserved across the different taxonomic groups within Annelida.
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Affiliation(s)
- Marc Ramos-Llorens
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - Francisco Hontoria
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - Juan C Navarro
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - David E K Ferrier
- The Scottish Oceans Institute, School of Biology, University of St. Andrews, St Andrews, Fife KY16 8LB, UK
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain.
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2
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Marrero M, Monroig Ó, Navarro JC, Ribes-Navarro A, Pérez JA, Galindo A, Rodríguez C. Metabolic and molecular evidence for long-chain PUFA biosynthesis capacity in the grass carp Ctenopharyngodon idella. Comp Biochem Physiol A Mol Integr Physiol 2022; 270:111232. [PMID: 35580802 DOI: 10.1016/j.cbpa.2022.111232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/09/2022] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
There is a growing interest to understand the capacity of farmed fish species to biosynthesise the physiologically important long-chain (≥C20) n-3 and n-6 polyunsaturated fatty acids (LC-PUFAs), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and arachidonic acid (ARA), from their C18 PUFA precursors available in the diet. In fish, the LC-PUFA biosynthesis pathways involve sequential desaturation and elongation reactions from α-linolenic acid (ALA) and linoleic acid (LA), catalysed by fatty acyl desaturases (Fads) and elongation of very long-chain fatty acids (Elovl) proteins. Our current understanding of the grass carp (Ctenopharyngodon idella) LC-PUFA biosynthetic capacity is limited despite representing the most farmed finfish produced worldwide. To address this knowledge gap, this study first aimed at characterising molecularly and functionally three genes (fads2, elovl5 and elovl2) with putative roles in LC-PUFA biosynthesis. Using an in vitro yeast-based system, we found that grass carp Fads2 possesses ∆8 and ∆5 desaturase activities, with ∆6 ability to desaturase not only the C18 PUFA precursors (ALA and LA) but also 24:5n-3 to 24:6n-3, a key intermediate to obtain DHA through the "Sprecher pathway". Additionally, the Elovl5 showed capacity to elongate C18 and C20 PUFA substrates, whereas Elovl2 was more active over C20 and C22. Collectively, the molecular cloning and functional characterisation of fads2, elovl5 and elovl2 demonstrated that the grass carp has all the enzymatic activities required to obtain ARA, EPA and DHA from LA and ALA. Importantly, the hepatocytes incubated with radiolabelled fatty acids confirmed the yeast-based results and demonstrated that these enzymes are functionally active.
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Affiliation(s)
- Manuel Marrero
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna 38206, Santa Cruz de Tenerife, Spain.
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - Juan Carlos Navarro
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - Alberto Ribes-Navarro
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, 12595 Ribera de Cabanes, Castellón, Spain
| | - José Antonio Pérez
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna 38206, Santa Cruz de Tenerife, Spain
| | - Ana Galindo
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna 38206, Santa Cruz de Tenerife, Spain
| | - Covadonga Rodríguez
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna 38206, Santa Cruz de Tenerife, Spain
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Weerasingha R, Kamarudin MS, Karim MMA, Ismail MFS. Replacing fish oil with crude palm oil in the diet of larval hybrid lemon fin barb (Barbonymus gonionotus ♀ × Hypsibarbus wetmorei ♂). AQUACULTURE REPORTS 2022; 24:101121. [DOI: 10.1016/j.aqrep.2022.101121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Kumar G, Sharma J, Goswami RK, Shrivastav AK, Tocher DR, Kumar N, Chakrabarti R. Freshwater Macrophytes: A Potential Source of Minerals and Fatty Acids for Fish, Poultry, and Livestock. Front Nutr 2022; 9:869425. [PMID: 35479737 PMCID: PMC9036174 DOI: 10.3389/fnut.2022.869425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
The freshwater macrophytes are abundant in tropical and subtropical climates. These macrophytes may be used as feed ingredients for fish and other animals. The nutritional value of twelve freshwater-cultured macrophytes was evaluated in the present study. Significantly higher crude protein (36.94–36.65%) and lipid (8.13–7.62%) were found in Lemna minor and Spirodela polyrhiza; ash content was significantly higher in Hydrilla verticillata, Wolffia globosa, and Pistia stratiotes (20.69–21.00%) compared with others. The highest levels of sodium, magnesium, chromium, and iron levels were recorded in P. stratiotes. H. verticillata was a rich source of copper, manganese, cobalt, and zinc; the contents of calcium, magnesium, strontium, and nickel were highest in S. polyrhiza. Selenium and potassium contents were higher in Salvinia natans and W. globosa, respectively. The n-6 and n-3 polyunsaturated fatty acids (PUFAs) contents were significantly higher in W. globosa and Ipomoea aquatica, respectively compared with others. Linoleic and α-linolenic acids were dominant n-6 and n-3 PUFAs. The highest value (4.04) of n-3/n-6 was found in I. aquatica. The ratio ranged from 0.61 to 2.46 in other macrophytes. This study reveals that macrophytes are rich sources of minerals, n-6 and n-3 PUFAs.
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Affiliation(s)
- Guddu Kumar
- Aqua Research Lab, Department of Zoology, University of Delhi, New Delhi, India
| | - JaiGopal Sharma
- Department of Biotechnology, Delhi Technological University, New Delhi, India
| | - Ravi Kumar Goswami
- Aqua Research Lab, Department of Zoology, University of Delhi, New Delhi, India
| | | | - Douglas R. Tocher
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, United Kingdom
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, China
| | - Neelesh Kumar
- Department of Biotechnology, Delhi Technological University, New Delhi, India
| | - Rina Chakrabarti
- Aqua Research Lab, Department of Zoology, University of Delhi, New Delhi, India
- *Correspondence: Rina Chakrabarti
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Nyunoya H, Noda T, Kawamoto Y, Hayashi Y, Ishibashi Y, Ito M, Okino N. Lack of ∆5 Desaturase Activity Impairs EPA and DHA Synthesis in Fish Cells from Red Sea Bream and Japanese Flounder. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:472-481. [PMID: 34176006 DOI: 10.1007/s10126-021-10040-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
Long-chain (≥ C20) polyunsaturated fatty acids (LC-PUFA), such as eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), are necessary for human health and are obtained from marine fish-derived oils. Marine fish are LC-PUFA-rich animals; however, many of them require LC-PUFA for growth. Therefore, it is suggested that they do not have sufficient ability to biosynthesize LC-PUFA. To evaluate in vivo LC-PUFA synthetic activity in fish cells, fish-derived cell lines from red sea bream (Pagrus major, PMS and PMF), Japanese flounder (Paralichthys olivaceus, HINAE), and zebrafish (Danio rerio, BRF41) were incubated with n-3 fatty acids labeled by radioisotopes or stable isotopes, and then, n-3 PUFA were analyzed by thin-layer chromatography or liquid chromatography-mass spectrometry. Labeled EPA and DHA were biosynthesized from labeled α-linolenic acid (18:3n-3) in BRF41, whereas they were not detected in PMS, PMF, or HINAE cells. We next cloned the fatty acid desaturase 2 (Fads2) cDNAs from PMF cells and zebrafish, expressed in budding yeasts, and then analyzed the substrate specificities of enzymes. As a result, we found that Fads2 from PMF cells was a ∆6/∆8 desaturase. Collectively, our study indicates that cell lines from red sea bream and Japanese flounder were not able to synthesize EPA or DHA by themselves, possibly due to the lack of ∆5 desaturase activity. Furthermore, this study provides a sensitive and reproducible non-radioactive method for evaluating LC-PUFA synthesis in fish cells using a stable isotope and liquid chromatography-mass spectrometry.
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Affiliation(s)
- Hayato Nyunoya
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Tatsuki Noda
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - You Kawamoto
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yasuhiro Hayashi
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
- Faculty of Pharma-Science, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Yohei Ishibashi
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Makoto Ito
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Nozomu Okino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan.
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Kabeya N, Ogino M, Ushio H, Haga Y, Satoh S, Navarro JC, Monroig Ó. A complete enzymatic capacity for biosynthesis of docosahexaenoic acid (DHA, 22 : 6n-3) exists in the marine Harpacticoida copepod Tigriopus californicus. Open Biol 2021; 11:200402. [PMID: 33906414 PMCID: PMC8080000 DOI: 10.1098/rsob.200402] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The long-standing paradigm establishing that global production of Omega-3 (n–3) long-chain polyunsaturated fatty acids (LC-PUFA) derived almost exclusively from marine single-cell organisms, was recently challenged by the discovery that multiple invertebrates possess methyl-end (or ωx) desaturases, critical enzymes enabling the biosynthesis of n–3 LC-PUFA. However, the question of whether animals with ωx desaturases have complete n–3 LC-PUFA biosynthetic pathways and hence can contribute to the production of these compounds in marine ecosystems remained unanswered. In the present study, we investigated the complete enzymatic complement involved in the n–3 LC-PUFA biosynthesis in Tigriopus californicus, an intertidal harpacticoid copepod. A total of two ωx desaturases, five front-end desaturases and six fatty acyl elongases were successfully isolated and functionally characterized. The T. californicus ωx desaturases enable the de novo biosynthesis of C18 PUFA such as linoleic and α-linolenic acids, as well as several n–3 LC-PUFA from n–6 substrates. Functions demonstrated in front-end desaturases and fatty acyl elongases unveiled various routes through which T. californicus can biosynthesize the physiologically important arachidonic and eicosapentaenoic acids. Moreover, T. californicus possess a Δ4 desaturase, enabling the biosynthesis of docosahexaenoic acid via the ‘Δ4 pathway’. In conclusion, harpacticoid copepods such as T. californicus have complete n–3 LC-PUFA biosynthetic pathways and such capacity illustrates major roles of these invertebrates in the provision of essential fatty acids to upper trophic levels.
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Affiliation(s)
- Naoki Kabeya
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato, Tokyo, Japan
| | - Masanari Ogino
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato, Tokyo, Japan
| | - Hideki Ushio
- Department of Aquatic Bioscience, The University of Tokyo, Yayoi 1-1-1, Bunkyo, Tokyo, Japan
| | - Yutaka Haga
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato, Tokyo, Japan
| | - Shuichi Satoh
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato, Tokyo, Japan
| | - Juan C Navarro
- Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes 12595, Castellón, Spain
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes 12595, Castellón, Spain
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7
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Xie D, Chen C, Dong Y, You C, Wang S, Monroig Ó, Tocher DR, Li Y. Regulation of long-chain polyunsaturated fatty acid biosynthesis in teleost fish. Prog Lipid Res 2021; 82:101095. [PMID: 33741387 DOI: 10.1016/j.plipres.2021.101095] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/24/2021] [Accepted: 03/12/2021] [Indexed: 12/26/2022]
Abstract
Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA, C20-24), including eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), are involved in numerous biological processes and have a range of health benefits. Fish have long been considered as the main source of n-3 LC-PUFA in human diets. However, the capacity for endogenous biosynthesis of LC-PUFA from C18 PUFA varies in fish species based on the presence, expression and activity of key enzymes including fatty acyl desaturases (Fads) and elongation of very long-chain fatty acids (Elovl) proteins. In this article, we review progress on the identified Fads and Elovl, as well as the regulatory mechanisms of LC-PUFA biosynthesis both at transcriptional and post-transcriptional levels in teleosts. The most comprehensive advances have been obtained in rabbitfish Siganus canaliculatus, a marine teleost demonstrated to have the entire pathway for LC-PUFA biosynthesis, including the roles of transcription factors hepatocyte nuclear factor 4α (Hnf4α), liver X receptor alpha (Lxrα), sterol regulatory element-binding protein 1 (Srebp-1), peroxisome proliferator-activated receptor gamma (Pparγ) and stimulatory protein 1 (Sp1), as well as post-transcriptional regulation by individual microRNA (miRNA) or clusters. This research has, for the first time, demonstrated the involvement of Hnf4α, Pparγ and miRNA in the regulation of LC-PUFA biosynthesis in vertebrates. The present review provides readers with a relatively comprehensive overview of the progress made into understanding LC-PUFA biosynthetic systems in teleosts, and some insights into improving endogenous LC-PUFA biosynthesis capacity aimed at reducing the dependence of aquafeeds on fish oil while maintaining or increasing flesh LC-PUFA content and the nutritional quality of farmed fish.
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Affiliation(s)
- Dizhi Xie
- College of Marine Sciences of South China Agricultural University & Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Cuiying Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China
| | - Yewei Dong
- Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510642, China
| | - Cuihong You
- Animal Science & Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510642, China
| | - Shuqi Wang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China.
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Castellón, Spain.
| | - Douglas R Tocher
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, China; Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling FK94LA, Scotland, United Kingdom
| | - Yuanyou Li
- College of Marine Sciences of South China Agricultural University & Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China.
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8
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Reda RM, El Asely A, Salah AS, Mahmoud MA. Replacement of dietary fish oil with plant oils improves the immunological responses and the antioxidant status in Oreochromis niloticus exposed to suboptimal temperature. FISH PHYSIOLOGY AND BIOCHEMISTRY 2020; 46:2181-2196. [PMID: 32862264 DOI: 10.1007/s10695-020-00867-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
Here, we investigated the effects of total dietary fish oil (FO) substitution with plant oil (PO) on hematological indices, immune status, antioxidant activity, IL1β and TNF-α gene expression, and hypoxia stress resistance in Oreochromis niloticus at suboptimal temperatures. Fish (n = 360) were randomly divided into 12 circular fiberglass tanks (500 L; 3 replicates for each dietary group, 30 fish/replicate, 90 fish/group). The control group was fed a basal diet with FO as the lipid source. The CO, SFO, and LSO groups were fed a basal diet with complete replacement of FO with corn, sunflower, and linseed oils, respectively. After 4 weeks, no effects on hematological indices were observed in fish fed the experimental diets. The LSO and CO groups showed a significant increase in γ globulin levels. The highest levels of non-specific immune parameters, antioxidant activity, and IL-1β and TNF-α gene expressions were recorded in the LSO group. The LSO group also exhibited good resistance to hypoxia stress. Therefore, the total dietary substitution of FO with PO (especially LSO and CO) is recommended as a valuable strategy to ameliorate the immunosuppressive effects of suboptimal temperatures and enhance the resistance of O. niloticus to hypoxia stress.
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Affiliation(s)
- Rasha M Reda
- Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharqia, 44511, Egypt.
| | - Amel El Asely
- Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine,, Benha University, Benha, Egypt
| | - Ayman S Salah
- Department of Animal Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine,, New Valley University, New Valley, Egypt
| | - Mohamed A Mahmoud
- Department of Physiology, Faculty of Veterinary Medicine,, New Valley University, New Valley, Egypt
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9
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Ferraz RB, Machado AM, Navarro JC, Cunha I, Ozório R, Salaro AL, Castro LFC, Monroig Ó. The fatty acid elongation genes elovl4a and elovl4b are present and functional in the genome of tambaqui (Colossoma macropomum). Comp Biochem Physiol B Biochem Mol Biol 2020; 245:110447. [PMID: 32325254 DOI: 10.1016/j.cbpb.2020.110447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 10/24/2022]
Abstract
Long-chain (C20-24) polyunsaturated fatty acids (LC-PUFA) are physiologically important nutrients for vertebrates including fish. Previous studies have addressed the metabolism of LC-PUFA in the Amazonian teleost tambaqui (Colossoma macropomum), an emerging species in Brazilian aquaculture, showing that all the desaturase and elongase activities required to convert C18 polyunsaturated fatty acids (PUFA) into LC-PUFA are present in tambaqui. Yet, elongation of very long-chain fatty acid 4 (Elovl4) proteins, which participate in the biosynthesis of very long-chain (>C24) saturated fatty acids (VLC-SFA) and very long-chain polyunsaturated fatty acids (VLC-PUFA), had not been characterized in this species. Here, we investigate the repertoire and function of two Elovl4 in tambaqui. Furthermore, we present the first draft genome assembly from tambaqui, and demonstrated the usefulness of this resource in nutritional physiology studies by isolating one of the tambaqui elovl4 genes. Our results showed that, similarly to other teleost species, two elovl4 gene paralogs termed as elovl4a and elovl4b, are present in tambaqui. Tambaqui elovl4a and elovl4b have open reading frames (ORF) of 948 and 912 base pairs, encoding putative proteins of 315 and 303 amino acids, respectively. Functional characterization in yeast showed that both Elovl4 enzymes have activity toward all the PUFA substrates assayed (18:3n-3, 18:2n-6, 18:4n-3, 18:3n-6, 20:5n-3, 20:4n-6, 22:5n-3, 22:4n-6 and 22:6n-3), producing elongated products of up to C36. Moreover, both Elovl4 were able to elongate 22:5n-3 to 24:5n-3, a key elongation step required for the synthesis of docosahexaenoic acid via the Sprecher pathway.
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Affiliation(s)
- Renato B Ferraz
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton De Matos S/N, 4450-208 Matosinhos, Portugal; ICBAS - Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - André M Machado
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton De Matos S/N, 4450-208 Matosinhos, Portugal
| | - Juan C Navarro
- Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain
| | - Isabel Cunha
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton De Matos S/N, 4450-208 Matosinhos, Portugal
| | - Rodrigo Ozório
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton De Matos S/N, 4450-208 Matosinhos, Portugal
| | - Ana L Salaro
- Department of Animal Biology, Federal University of Viçosa, Avenida Peter Henry Rolfs, s/n - Campus Universitário, Viçosa, MG 36570-900, Brazil
| | - L Filipe C Castro
- CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton De Matos S/N, 4450-208 Matosinhos, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua Campo Alegre s/n, 4169-007, Portugal.
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
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Coutinho NM, Canto ACVDCS, Mársico ET, Silva FAD, Keller LAM, Conte-Junior CA, Monteiro MLG. Fatty acid composition and influence of temperature on the lipid stability of Arapaima gigas meat. BRAZILIAN JOURNAL OF FOOD TECHNOLOGY 2019. [DOI: 10.1590/1981-6723.13218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract The nutritional quality and lipid stability of Arapaima gigas fillets were investigated. A total of 27.32 kg of A. gigas fillets were obtained and the proximate composition and fatty acid profile immediately determined. In addition, the lipid oxidation parameters were analyzed during 15 and 90 days at 4 °C and –20 °C, respectively. The A. gigas fillets presented high protein (> 15%) and low lipid (< 2%) contents with elevated polyunsaturated fatty acid (PUFAs) contents (43.97%). The nutritional quality indices were the atherogenicity index (0.35), thrombogenicity index (0.28) and the hypocholesterolemic acid/ hypercholesterolemic acid ratio (2.37). Overall, an increase followed by a decrease was observed in the peroxide index (PI) and malondialdehyde content (MDA) results at both storage temperatures ( p < 0.05). The lipid profile exhibited great nutritional quality, however new conservation methods should be investigated for this matrix due to increased lipid oxidation during refrigerated and frozen storage.
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11
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Ferraz RB, Kabeya N, Lopes-Marques M, Machado AM, Ribeiro RA, Salaro AL, Ozório R, Castro LFC, Monroig Ó. A complete enzymatic capacity for long-chain polyunsaturated fatty acid biosynthesis is present in the Amazonian teleost tambaqui, Colossoma macropomum. Comp Biochem Physiol B Biochem Mol Biol 2019; 227:90-97. [DOI: 10.1016/j.cbpb.2018.09.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 12/30/2022]
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12
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Kühn G, Pallauf K, Schulz C, Birringer M, Diaz-Rica B, de Pascual-Teresa S, Rimbach G. Resveratrol Modulates Desaturase Expression and Fatty Acid Composition of Cultured Hepatocytes. Front Nutr 2018; 5:106. [PMID: 30488034 PMCID: PMC6246710 DOI: 10.3389/fnut.2018.00106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/23/2018] [Indexed: 11/13/2022] Open
Abstract
This study aimed to evaluate whether resveratrol (RSV) and its microbial metabolites dihydro-resveratrol (DHR) and lunularin (LUN) affected fatty acid metabolism and omega-3 polyunsaturated fatty acid (n3-PUFA) synthesis in cultured hepatocytes. To this end, cultured human HepG2 hepatocytes were treated with non-toxic concentrations of these polyphenols (40 μM) and Δ5- and Δ6-desaturase (FADS1 and FADS2, respectively) expression was measured. Resveratrol induced both genes but DHR and LUN showed no effect. Co-incubation of RSV with α-linolenic acid (ALA) also induced FADS1 and FADS2 expression. Moreover, transcription of carnitine palmitoyltransferase 1A and fatty acid synthase expression was increased, indicating induction of β-oxidation and fatty acid synthesis, respectively. Using gas chromatography to measure fatty acid levels, we observed the impact of RSV with and without ALA treatment on fatty acid composition. However, RSV reduced unsaturated while increasing saturated fatty acid levels. We found lower amounts of monounsaturated fatty acids (16:1n-7c, 18:1n-9c, 18:1n7c, and 20:1n-9) and n3-PUFA docosahexaenoic acid whereas unsaturated fatty acid levels, especially of stearic acid, were elevated. Of interest, once we co-incubated the cells with RSV together with bovine serum albumin, we found no differences in gene expression compared to cells without RSV treatment. Although we found no positive effect of RSV on n3-PUFA synthesis, the stilbene could possibly prevent cellular stress by decreasing unsaturated fatty acid levels.
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Affiliation(s)
- Gianna Kühn
- Institute of Human Nutrition and Food Science, University of Kiel, Kiel, Germany
| | - Kathrin Pallauf
- Institute of Human Nutrition and Food Science, University of Kiel, Kiel, Germany
| | - Carsten Schulz
- Institute of Animal Breeding and Husbandry, University of Kiel, Kiel, Germany.,GMA-Gesellschaft für Marine Aquakultur mbH, Büsum, Germany
| | - Marc Birringer
- Department of Nutritional, Food, and Consumer Sciences, University of Applied Sciences Fulda, Fulda, Germany
| | - Beatriz Diaz-Rica
- Department of Metabolism and Nutrition, Institute of Food Science, Food Technology and Nutrition (ICTAN-CSIC), Madrid, Spain
| | - Sonia de Pascual-Teresa
- Department of Metabolism and Nutrition, Institute of Food Science, Food Technology and Nutrition (ICTAN-CSIC), Madrid, Spain
| | - Gerald Rimbach
- Institute of Human Nutrition and Food Science, University of Kiel, Kiel, Germany
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Nayak M, Pradhan A, Giri SS, Samanta M, Konkimalla VB, Saha A. Molecular characterization, tissue distribution and differential nutritional regulation of putative Elovl5 elongase in silver barb (Puntius gonionotus). Comp Biochem Physiol B Biochem Mol Biol 2018; 217:27-39. [DOI: 10.1016/j.cbpb.2017.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 12/05/2017] [Accepted: 12/05/2017] [Indexed: 01/31/2023]
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14
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Zárate R, el Jaber-Vazdekis N, Tejera N, Pérez JA, Rodríguez C. Significance of long chain polyunsaturated fatty acids in human health. Clin Transl Med 2017; 6:25. [PMID: 28752333 PMCID: PMC5532176 DOI: 10.1186/s40169-017-0153-6] [Citation(s) in RCA: 272] [Impact Index Per Article: 38.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/11/2017] [Indexed: 12/12/2022] Open
Abstract
In the last decades, the development of new technologies applied to lipidomics has revitalized the analysis of lipid profile alterations and the understanding of the underlying molecular mechanisms of lipid metabolism, together with their involvement in the occurrence of human disease. Of particular interest is the study of omega-3 and omega-6 long chain polyunsaturated fatty acids (LC-PUFAs), notably EPA (eicosapentaenoic acid, 20:5n-3), DHA (docosahexaenoic acid, 22:6n-3), and ARA (arachidonic acid, 20:4n-6), and their transformation into bioactive lipid mediators. In this sense, new families of PUFA-derived lipid mediators, including resolvins derived from EPA and DHA, and protectins and maresins derived from DHA, are being increasingly investigated because of their active role in the "return to homeostasis" process and resolution of inflammation. Recent findings reviewed in the present study highlight that the omega-6 fatty acid ARA appears increased, and omega-3 EPA and DHA decreased in most cancer tissues compared to normal ones, and that increments in omega-3 LC-PUFAs consumption and an omega-6/omega-3 ratio of 2-4:1, are associated with a reduced risk of breast, prostate, colon and renal cancers. Along with their lipid-lowering properties, omega-3 LC-PUFAs also exert cardioprotective functions, such as reducing platelet aggregation and inflammation, and controlling the presence of DHA in our body, especially in our liver and brain, which is crucial for optimal brain functionality. Considering that DHA is the principal omega-3 FA in cortical gray matter, the importance of DHA intake and its derived lipid mediators have been recently reported in patients with major depressive and bipolar disorders, Alzheimer disease, Parkinson's disease, and amyotrophic lateral sclerosis. The present study reviews the relationships between major diseases occurring today in the Western world and LC-PUFAs. More specifically this review focuses on the dietary omega-3 LC-PUFAs and the omega-6/omega-3 balance, in a wide range of inflammation disorders, including autoimmune diseases. This review suggests that the current recommendations of consumption and/or supplementation of omega-3 FAs are specific to particular groups of age and physiological status, and still need more fine tuning for overall human health and well being.
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Affiliation(s)
- Rafael Zárate
- Canary Islands Cancer Research Institute (ICIC), Ave. La Trinidad 61, Torre A. Arévalo, 7th floor, 38204 La Laguna, Tenerife Spain
| | - Nabil el Jaber-Vazdekis
- Centre Algatech, Institute of Microbiology, Academy of Sciences of the Czech Republic, Třeboň, Czech Republic
| | - Noemi Tejera
- Department of Nutrition and Preventive Medicine, Norwich Medical School, University of East Anglia, Norwich, NR4 7UQ UK
| | - José A. Pérez
- Department of Animal Biology, Soil Science and Geology (Animal Physiology Unit), Faculty of Sciences, Universidad de La Laguna, Ave. Astrofísico Francisco Sánchez s/n, 38206 La Laguna, Tenerife Spain
| | - Covadonga Rodríguez
- Department of Animal Biology, Soil Science and Geology (Animal Physiology Unit), Faculty of Sciences, Universidad de La Laguna, Ave. Astrofísico Francisco Sánchez s/n, 38206 La Laguna, Tenerife Spain
- Institute of Biomedical Technologies (ITB), Universidad de La Laguna, Campus de Ofra, 38071 La Laguna, Tenerife Spain
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15
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Abstract
Docosahexaenoic acid (DHA) plays important physiological roles in vertebrates. Studies in rats and rainbow trout confirmed that DHA biosynthesis proceeds through the so-called “Sprecher pathway”, a biosynthetic process requiring a Δ6 desaturation of 24:5n−3 to 24:6n−3. Alternatively, some teleosts possess fatty acyl desaturases 2 (Fads2) that enable them to biosynthesis DHA through a more direct route termed the “Δ4 pathway”. In order to elucidate the prevalence of both pathways among teleosts, we investigated the Δ6 ability towards C24 substrates of Fads2 from fish with different evolutionary and ecological backgrounds. Subsequently, we retrieved public databases to identify Fads2 containing the YXXN domain responsible for the Δ4 desaturase function, and consequently enabling these species to operate the Δ4 pathway. We demonstrated that, with the exception of Δ4 desaturases, fish Fads2 have the ability to operate as Δ6 desaturases towards C24 PUFA enabling them to synthesise DHA through the Sprecher pathway. Nevertheless, the Δ4 pathway represents an alternative route in some teleosts and we identified the presence of putative Δ4 Fads2 in a further 11 species and confirmed the function as Δ4 desaturases of Fads2 from medaka and Nile tilapia. Our results demonstrated that two alternative pathways for DHA biosynthesis exist in teleosts.
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16
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Nayak M, Saha A, Pradhan A, Samanta M, Giri SS. Dietary fish oil replacement by linseed oil: Effect on growth, nutrient utilization, tissue fatty acid composition and desaturase gene expression in silver barb (Puntius gonionotus) fingerlings. Comp Biochem Physiol B Biochem Mol Biol 2016; 205:1-12. [PMID: 27913275 DOI: 10.1016/j.cbpb.2016.11.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/14/2016] [Accepted: 11/24/2016] [Indexed: 10/20/2022]
Abstract
Silver barb (Puntius gonionotus) is considered a promising medium carp species for freshwater aquaculture in Asia. This study in silver barb was carried out to evaluate the effects of total or partial substitution of dietary fish oil (FO) with linseed oil (LO) on growth, nutrient utilization, whole-body composition, muscle and liver fatty acid composition. Fish (12.1±0.4g of initial body weight) were fed for 60days with five experimental iso-proteinous, iso-lipidic and iso-caloric diets in which FO (control diet) was replaced by 33.3%, 50%, 66.7% and 100% LO. Final weight, weight gain, percent weight gain, SGR decreased linearly (p<0.001) with increasing LO levels in the diets. Dietary LO substitution levels did not significantly (p>0.05) affect the feed conversion ratio (FCR), protein efficiency ratio (PER) and whole body proximate composition. Furthermore, enhanced level of LO increased α-linolenic acid (ALA; 18:3n3) and linoleic acid (LA; 18:2n6) and decreased eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n3) in muscle and liver. To understand the molecular mechanism of long chain-polyunsaturated fatty acid (LC-PUFA) biosynthesis, we cloned and characterized the fatty acyl Δ6 desaturase (Δ6 fad) cDNA and investigated its expression in various organs/tissues following replacement of FO with LO in the diet. The full-length Δ6 fad cDNA was 2056bp encoding 444 amino acids and was widely expressed in various organs/tissues. Replacement of FO with LO increased the expression of Δ6 fad mRNA in liver, muscle and intestine but no significant difference was found in the brain.
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Affiliation(s)
- Madhusmita Nayak
- Division of Fish Nutrition and Physiology, ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, India
| | - Ashis Saha
- Division of Fish Nutrition and Physiology, ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, India.
| | - Avinash Pradhan
- Division of Fish Nutrition and Physiology, ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, India
| | - Mrinal Samanta
- Division of Fish Nutrition and Physiology, ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, India
| | - Shiba Shankar Giri
- Division of Fish Nutrition and Physiology, ICAR-Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar, Odisha, India
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17
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Long-chain polyunsaturated fatty acid biosynthesis in chordates: Insights into the evolution of Fads and Elovl gene repertoire. Prog Lipid Res 2016; 62:25-40. [DOI: 10.1016/j.plipres.2016.01.001] [Citation(s) in RCA: 242] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 12/28/2015] [Accepted: 01/01/2016] [Indexed: 01/01/2023]
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18
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Abdul Hamid NK, Carmona-Antoñanzas G, Monroig Ó, Tocher DR, Turchini GM, Donald JA. Isolation and Functional Characterisation of a fads2 in Rainbow Trout (Oncorhynchus mykiss) with Δ5 Desaturase Activity. PLoS One 2016; 11:e0150770. [PMID: 26943160 PMCID: PMC4778901 DOI: 10.1371/journal.pone.0150770] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/17/2016] [Indexed: 11/18/2022] Open
Abstract
Rainbow trout, Oncorhynchus mykiss, are intensively cultured globally. Understanding their requirement for long-chain polyunsaturated fatty acids (LC-PUFA) and the biochemistry of the enzymes and biosynthetic pathways required for fatty acid synthesis is important and highly relevant in current aquaculture. Most gnathostome vertebrates have two fatty acid desaturase (fads) genes with known functions in LC-PUFA biosynthesis and termed fads1 and fads2. However, teleost fish have exclusively fads2 genes. In rainbow trout, a fads2 cDNA had been previously cloned and found to encode an enzyme with Δ6 desaturase activity. In the present study, a second fads2 cDNA was cloned from the liver of rainbow trout and termed fads2b. The full-length mRNA contained 1578 nucleotides with an open reading frame of 1365 nucleotides that encoded a 454 amino acid protein with a predicted molecular weight of 52.48 kDa. The predicted Fads2b protein had the characteristic traits of the microsomal Fads family, including an N-terminal cytochrome b5 domain containing the heme-binding motif (HPPG), histidine boxes (HDXGH, HFQHH and QIEHH) and three transmembrane regions. The fads2b was expressed predominantly in the brain, liver, intestine and pyloric caeca. Expression of the fasd2b in yeast generated a protein that was found to specifically convert eicosatetraenoic acid (20:4n-3) to eicosapentaenoic acid (20:5n-3), and therefore functioned as a Δ5 desaturase. Therefore, rainbow trout have two fads2 genes that encode proteins with Δ5 and Δ6 desaturase activities, respectively, which enable this species to perform all the desaturation steps required for the biosynthesis of LC-PUFA from C18 precursors.
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Affiliation(s)
- Noor Khalidah Abdul Hamid
- Deakin University, School of Life and Environmental Sciences, Waurn Ponds, Geelong, Victoria, Australia
- Universiti Sains Malaysia, School of Biological Sciences, Penang, Malaysia
- * E-mail:
| | - Greta Carmona-Antoñanzas
- University of Stirling, Institute of Aquaculture, School of Natural Sciences, Stirling, Scotland, United Kingdom
| | - Óscar Monroig
- University of Stirling, Institute of Aquaculture, School of Natural Sciences, Stirling, Scotland, United Kingdom
| | - Douglas R. Tocher
- University of Stirling, Institute of Aquaculture, School of Natural Sciences, Stirling, Scotland, United Kingdom
| | - Giovanni M. Turchini
- Deakin University, School of Life and Environmental Sciences, Waurn Ponds, Geelong, Victoria, Australia
| | - John A. Donald
- Deakin University, School of Life and Environmental Sciences, Waurn Ponds, Geelong, Victoria, Australia
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19
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Sawyer JM, Arts MT, Arhonditsis G, Diamond ML. A general model of polyunsaturated fatty acid (PUFA) uptake, loss and transformation in freshwater fish. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2015.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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A nutritionally-enhanced oil from transgenic Camelina sativa effectively replaces fish oil as a source of eicosapentaenoic acid for fish. Sci Rep 2015; 5:8104. [PMID: 25632018 PMCID: PMC4309969 DOI: 10.1038/srep08104] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 01/06/2015] [Indexed: 12/17/2022] Open
Abstract
For humans a daily intake of up to 500 mg omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) is recommended, amounting to an annual requirement of 1.25 million metric tonnes (mt) for a population of 7 billion people. The annual global supply of n-3 LC-PUFA cannot meet this level of requirement and so there is a large gap between supply and demand. The dietary source of n-3 LC-PUFA, fish and seafood, is increasingly provided by aquaculture but using fish oil in feeds to supply n-3 LC-PUFA is unsustainable. Therefore, new sources of n-3 LC-PUFA are required to supply the demand from aquaculture and direct human consumption. One approach is metabolically engineering oilseed crops to synthesize n-3 LC-PUFA in seeds. Transgenic Camelina sativa expressing algal genes was used to produce an oil containing n-3 LC-PUFA to replace fish oil in salmon feeds. The oil had no detrimental effects on fish performance, metabolic responses or the nutritional quality of the fillets of the farmed fish.
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21
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Abstract
The proximate composition of male and femaleLeuciscus lepidusin Beyşehir Lake was investigated. The fatty acid profiles of total lipid, phospholipid, and triacylglycerol in muscle and liver of male and femaleL. lepiduswere evaluated by gas chromatography. Proximate analyses showed that meat of male and femaleL. lepidushad 15.13 ± 0.04 and 18.75 ± 0.11% fat, 20.42 ± 0.45 and 22.21 ± 0.56% protein, 65.47 ± 1.37 and 61.28 ± 1.03% moisture, and 1.51 ± 0.05 and 1.50 ± 0.03% ash, respectively. The percentage of total saturated fatty acids was higher in liver than in muscle, whereas the total polyunsaturated fatty acid (PUFA) content was the lowest in all fatty acid profiles. The phospholipids contained more PUFAs than triacylglycerol. Analysis of variance indicated significant differences (P<0.05) between male (47.51%) and female (49.98%) muscle PUFAs in total lipid. The proportion of omega 3 (ω3) to omega 6 (ω6) fatty acids of total lipid was 3.15 in male and 3.68 in female. The ratio is an important indicator for comparing the value of fish oil. Therefore, it was concluded thatL. lepiduswas considered to be a high quality product for healthy food choice. Additionally, femaleL. lepidusmay especially be used to produce fish oil supplements from freshwater fish combined with vegetable oils.
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22
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Monroig Ó, Tocher DR, Navarro JC. Biosynthesis of polyunsaturated fatty acids in marine invertebrates: recent advances in molecular mechanisms. Mar Drugs 2013; 11:3998-4018. [PMID: 24152561 PMCID: PMC3826146 DOI: 10.3390/md11103998] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 10/03/2013] [Accepted: 10/09/2013] [Indexed: 01/09/2023] Open
Abstract
Virtually all polyunsaturated fatty acids (PUFA) originate from primary producers but can be modified by bioconversions as they pass up the food chain in a process termed trophic upgrading. Therefore, although the main primary producers of PUFA in the marine environment are microalgae, higher trophic levels have metabolic pathways that can produce novel and unique PUFA. However, little is known about the pathways of PUFA biosynthesis and metabolism in the levels between primary producers and fish that are largely filled by invertebrates. It has become increasingly apparent that, in addition to trophic upgrading, de novo synthesis of PUFA is possible in some lower animals. The unequivocal identification of PUFA biosynthetic pathways in many invertebrates is complicated by the presence of other organisms within them. These organisms include bacteria and algae with PUFA biosynthesis pathways, and range from intestinal flora to symbiotic relationships that can involve PUFA translocation to host organisms. This emphasizes the importance of studying biosynthetic pathways at a molecular level, and the continual expansion of genomic resources and advances in molecular analysis is facilitating this. The present paper highlights recent research into the molecular and biochemical mechanisms of PUFA biosynthesis in marine invertebrates, particularly focusing on cephalopod molluscs.
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Affiliation(s)
- Óscar Monroig
- Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes 12595, Castellon, Spain.
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23
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Δ-6 Desaturase substrate competition: dietary linoleic acid (18:2n-6) has only trivial effects on α-linolenic acid (18:3n-3) bioconversion in the teleost rainbow trout. PLoS One 2013; 8:e57463. [PMID: 23460861 PMCID: PMC3583879 DOI: 10.1371/journal.pone.0057463] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 01/22/2013] [Indexed: 01/08/2023] Open
Abstract
It is generally accepted that, in vertebrates, omega-3 (n-3) and omega-6 (n-6) poly-unsaturated fatty acids (PUFA) compete for Δ-6 desaturase enzyme in order to be bioconverted into long-chain PUFA (LC-PUFA). However, recent studies into teleost fatty acid metabolism suggest that these metabolic processes may not conform entirely to what has been previously observed in mammals and other animal models. Recent work on rainbow trout has led us to question specifically if linoleic acid (LA, 18∶2n-6) and α-linolenic acid (ALA, 18∶3n-3) (Δ-6 desaturase substrates) are in direct competition for access to Δ-6 desaturase. Two experimental diets were formulated with fixed levels of ALA, while LA levels were varied (high and low) to examine if increased availability of LA would result in decreased bioconversion of ALA to its LC-PUFA products through substrate competition. No significant difference in ALA metabolism towards n-3 LC-PUFA was exhibited between diets while significant differences were observed in LA metabolism towards n-6 LC-PUFA. These results are evidence for minor if any competition between substrates for Δ-6 desaturase, suggesting that, paradoxically, the activity of Δ-6 desaturase on n-3 and n-6 substrates is independent. These results call for a paradigm shift in the way we approach teleost fatty acid metabolism. The findings are also important with regard to diet formulation in the aquaculture industry as they indicate that there should be no concern for possible substrate competition between 18∶3n-3 and 18∶2n-6, when aiming at increased n-3 LC-PUFA bioconversion in vivo.
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24
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Ren HT, Yu JH, Xu P, Tang YK. 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). Comp Biochem Physiol B Biochem Mol Biol 2012; 163:184-92. [DOI: 10.1016/j.cbpb.2012.05.016] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 05/22/2012] [Accepted: 05/22/2012] [Indexed: 12/01/2022]
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25
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Cleveland BJ, Francis DS, Turchini GM. Echium oil provides no benefit over linseed oil for (n-3) long-chain PUFA biosynthesis in rainbow trout. J Nutr 2012; 142:1449-55. [PMID: 22739372 DOI: 10.3945/jn.112.161497] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The implementation of alternative lipid sources for use in aquaculture is of considerable interest globally. However, the possible benefit of using stearidonic acid (SDA)-rich fish oil (FO) alternatives has led to scientific confusion. Two hundred and forty rainbow trout (Oncorhynchus mykiss) were fed 1 of 4 diets (3 replicate tanks/treatment) containing either FO, linseed oil (LO), echium oil, or mixed vegetable oil (72% LO, 23% sunflower oil, and 6% canola oil) as the dietary lipid source (16.5%) for 73 d to investigate the competition and long-chain PUFA (LC-PUFA) biosynthesis between the fatty acid substrates α-linolenic acid (ALA) and SDA. SDA was more efficiently bioconverted to LC-PUFA compared with ALA. However, when the dietary lipid sources were directly compared, the increased provision of C18 PUFA within the LO diet resulted in no significant differences in (n-3) LC-PUFA content compared with fish fed the other diets. This study therefore shows that, rather than the previously speculated substrate competition, the limiting process in the apparent in vivo (n-3) LC-PUFA biosynthesis appears to be substrate availability. Rainbow trout fed the SDA- and ALA-rich dietary lipid sources subsequently had similar significant reductions in (n-3) LC-PUFA compared with fish fed the FO diet, therefore providing no additional dietary benefit on (n-3) LC-PUFA concentrations.
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Affiliation(s)
- Benjamin J Cleveland
- School of Life and Environmental Sciences, Deakin University, Warrnambool, Victoria, Australia
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26
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Schiller Vestergren A, Wagner L, Pickova J, Rosenlund G, Kamal-Eldin A, Trattner S. Sesamin modulates gene expression without corresponding effects on fatty acids in Atlantic salmon (Salmo salar L.). Lipids 2012; 47:897-911. [PMID: 22790840 DOI: 10.1007/s11745-012-3697-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
Abstract
This study examined the effects of sesamin inclusion in vegetable oil-based diets fed to Atlantic salmon (Salmo salar L.). The diets used differed in n-6/n-3 fatty acid (FA) ratio (0.5 and 1) and sesamin content (high 5.8 g/kg, low 1.16 g/kg and no sesamin). The oils used in the feeds were a mixture of rapeseed, linseed and palm oil. Fish were fed for 4 months. Fatty acids and expression of hepatic genes involved in transcription, lipid uptake, desaturation, elongation and β-oxidation were measured. No major effects on the percentage of DHA in white muscle, liver triacylglycerol and phospholipid fraction were detected. Genes involved in β-oxidation, elongation and desaturation were affected by sesamin addition. Limited effects were seen on any of the transcription factors tested and no effect was seen on the expression of peroxisome proliferator-activated receptors (PPAR). Expression of both SREBP-1 and SREBP-2 increased with sesamin addition. It was concluded that supplementation of fish feed with a high level of sesamin had a negative effect on the growth rate and live weight and did not alter the proportions of DHA in tissues even though gene expression was affected. Thus, more studies are needed to formulate a diet that would increase the percentage of DHA in fish without negative effects on fish growth.
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Affiliation(s)
- A Schiller Vestergren
- Department of Food Science, Swedish University of Agricultural Sciences-SLU, Uppsala BioCenter, P.O. Box 7051, 75007 Uppsala, Sweden
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27
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Thanuthong T, Francis DS, Senadheera SPSD, Jones PL, Turchini GM. LC-PUFA biosynthesis in rainbow trout is substrate limited: use of the whole body fatty acid balance method and different 18:3n-3/18:2n-6 ratios. Lipids 2011; 46:1111-27. [PMID: 21892784 DOI: 10.1007/s11745-011-3607-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 08/11/2011] [Indexed: 10/17/2022]
Abstract
Five experimental diets with constant total C(18) PUFA and varying 18:3n-3/18:2n-6 ratios were fed to rainbow trout over an entire production cycle. The whole-body fatty acid balance method demonstrated a clear trend of progressively reduced fatty acid bioconversion activity along the n-3 and n-6 pathways, up to the production of 20:5n-3 and 20:4n-6, respectively. This suggests that the pathway exhibits a "funnel like" progression of activity rather than the existence of a single rate limiting step. The production of 22:5n-3 and 22:6n-3 was more active than that of 20:5n-3. However, despite this trend in reduced apparent in vivo net enzyme activity, the efficiency of the various bioconversion steps (measured as % of bioconverted substrate) confirmed an opposing trend. A 3.2-fold higher Δ-6 desaturase affinity towards 18:3n-3 over 18:2n-6 and an 8-fold greater Δ-5 desaturase affinity towards 20:4n-3 over 20:3n-6 were recorded. The main results of the study were that (1) rainbow trout are quite efficient at bioconverting 18:3n-3 to 22:6n-3, and (2) the LC-PUFA biosynthetic pathway is substrate limited. Fillet n-3 LC-PUFA concentrations increased with the increasing dietary supply of 18:3n-3. Despite an almost identical dietary supply of n-3 LC-PUFA, originating from the fish meal fraction of the diets, the fillets of trout fed the diet richest in 18:3n-3 were 2-fold higher in n-3 LC-PUFA than fish fed low 18:3n-3 diets. Nevertheless, fillets of trout fed a fish oil control diet contained more than double the amount of n-3 LC-PUFA compared to fish fed the diets richest in 18:3n-3.
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Affiliation(s)
- T Thanuthong
- School of Life and Environmental Sciences, Deakin University, Warrnambool, VIC, Australia
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Delta-8 desaturation activity varies among fatty acyl desaturases of teleost fish: High activity in delta-6 desaturases of marine species. Comp Biochem Physiol B Biochem Mol Biol 2011; 159:206-13. [DOI: 10.1016/j.cbpb.2011.04.007] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 04/25/2011] [Accepted: 04/25/2011] [Indexed: 11/19/2022]
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Mohd-Yusof NY, Monroig O, Mohd-Adnan A, Wan KL, Tocher DR. Investigation of highly unsaturated fatty acid metabolism in the Asian sea bass, Lates calcarifer. FISH PHYSIOLOGY AND BIOCHEMISTRY 2010; 36:827-843. [PMID: 20532815 DOI: 10.1007/s10695-010-9409-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 09/16/2009] [Indexed: 05/29/2023]
Abstract
Lates calcarifer, commonly known as the Asian sea bass or barramundi, is an interesting species that has great aquaculture potential in Asia including Malaysia and also Australia. We have investigated essential fatty acid metabolism in this species, focusing on the endogenous highly unsaturated fatty acid (HUFA) synthesis pathway using both biochemical and molecular biological approaches. Fatty acyl desaturase (Fad) and elongase (Elovl) cDNAs were cloned and functional characterization identified them as ∆6 Fad and Elovl5 elongase enzymes, respectively. The ∆6 Fad was equally active toward 18:3n-3 and 18:2n-6, and Elovl5 exhibited elongation activity for C18-20 and C20-22 elongation and a trace of C22-24 activity. The tissue profile of gene expression for ∆6 fad and elovl5 genes, showed brain to have the highest expression of both genes compared to all other tissues. The results of tissue fatty acid analysis showed that the brain contained more docosahexaenoic acid (DHA, 22:6n-3) than flesh, liver and intestine. The HUFA synthesis activity in isolated hepatocytes and enterocytes using [1-(14)C]18:3n-3 as substrate was very low with the only desaturated product detected being 18:4n-3. These findings indicate that L. calcarifer display an essential fatty acid pattern similar to other marine fish in that they appear unable to synthesize HUFA from C18 substrates. High expression of ∆6 fad and elovl5 genes in brain may indicate a role for these enzymes in maintaining high DHA levels in neural tissues through conversion of 20:5n-3.
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Affiliation(s)
- N Y Mohd-Yusof
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor DE, Malaysia.
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30
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Abstract
Biosynthesis of the highly biologically active long-chain polyunsaturated fatty acids, arachidonic (ARA), eicosapentaenoic (EPA), and docosahexaenoic (DHA) acids, in vertebrates requires the introduction of up to three double bonds catalyzed by fatty acyl desaturases (Fad). Synthesis of ARA is achieved by Δ6 desaturation of 182n - 6 to produce 183n - 6 that is elongated to 203n - 6 followed by Δ5 desaturation. Synthesis of EPA from 183n - 3 requires the same enzymes and pathway as for ARA, but DHA synthesis reportedly requires two further elongations, a second Δ6 desaturation and a peroxisomal chain shortening step. This paper describes cDNAs, fad1 and fad2, isolated from the herbivorous, marine teleost fish (Siganus canaliculatus) with high similarity to mammalian Fad proteins. Functional characterization of the cDNAs by heterologous expression in the yeast Saccharomyces cerevisiae showed that Fad1 was a bifunctional Δ6/Δ5 Fad. Previously, functional dual specificity in vertebrates had been demonstrated for a zebrafish Danio rerio Fad and baboon Fad, so the present report suggests bifunctionality may be more widespread in vertebrates. However, Fad2 conferred on the yeast the ability to convert 225n - 3 to DHA indicating that this S. canaliculatus gene encoded an enzyme having Δ4 Fad activity. This is a unique report of a Fad with Δ4 activity in any vertebrate species and indicates that there are two possible mechanisms for DHA biosynthesis, a direct route involving elongation of EPA to 225n - 3 followed by Δ4 desaturation, as well as the more complicated pathway as described above.
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Morais S, Monroig O, Zheng X, Leaver MJ, Tocher DR. Highly unsaturated fatty acid synthesis in Atlantic salmon: characterization of ELOVL5- and ELOVL2-like elongases. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2009; 11:627-39. [PMID: 19184219 DOI: 10.1007/s10126-009-9179-0] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 01/05/2009] [Indexed: 05/09/2023]
Abstract
Fish species vary in their capacity to biosynthesize the n-3 long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids that are crucial to the health of higher vertebrates. The synthesis of LC-PUFA involves enzyme-mediated fatty acyl desaturation and elongation. Previously, a complementary DNA (cDNA) for an elongase, now termed elovl5a, had been cloned from Atlantic salmon. Here, we report on the cloning of two new elongase cDNAs: a second elovl5b elongase, corresponding to a 294-amino-acid (aa) protein, and an elovl2-like elongase, coding for a 287-aa protein, characterized for the first time in a nonmammalian vertebrate. Heterologous expression in yeast showed that the salmon Elovl5b elongated C18 and C20 PUFA, with low activity towards C22, while Elovl2 elongated C20 and C22 PUFA with lower activity towards C18 PUFA. All three transcripts showed predominant expression in the intestine and liver, followed by the brain. Elongase expression showed differential nutritional regulation. Levels of elovl5b and particularly of elovl2, but not of elovl5a, transcripts were significantly increased in liver of salmon fed vegetable oils (VO) compared to fish fed fish oil (FO). Intestinal expression showed a similar pattern. Phylogenetic comparisons indicate that, in contrast to salmon and zebra fish, Acanthopterygian fish species lack elovl2 which is consistent with their negligible ability to biosynthesize LC-PUFA and to adapt to VO dietary inclusion, compared to predominantly freshwater salmonids. Thus, the presence of elovl2 in salmon explains the ability of this species to biosynthesize LC-PUFA and may provide a biotechnological tool to produce enhanced levels of LC-PUFA, particularly DHA, in transgenic organisms.
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Affiliation(s)
- Sofia Morais
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, Scotland, UK.
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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. Br J Nutr 2008; 101:1452-62. [PMID: 18838020 DOI: 10.1017/s0007114508088053] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Four replicated groups of sea bass (Dicentrarchus labrax) larvae were fed diets containing an extra-high level of highly unsaturated fatty acids (HUFA) (XH; 3.7 % EPA+DHA), a high level of HUFA (HH; 1.7 %), a low level of HUFA (LH; 0.7 %) or an extra-low level of HUFA (XLH; 0.5 %) from day 6 to day 45 (experiment 1; XH1, HH1, LH1, XLH1). After a subsequent 1-month period feeding a commercial diet (2.7 % EPA+DHA), the capacity of the four initial groups to adapt to an n-3 HUFA-restricted diet (0.3 % EPA+DHA; R-groups: XH2R, HH2R, LH2R, XLH2R) was tested for 35 d. Larval dietary treatments had no effect on larval and juvenile survival rates. The wet weight of day 45 larvae was higher in XH1 and HH1 (P < 0.001), but the R-juvenile mass gains were similar in all treatments. Delta-6-desaturase (Delta6D) mRNA level was higher in LH1 and XLH1 at day 45 (P < 0.001), and higher in LH2R and XLH2R, with a significant increase at day 118.Concomitantly, PPARalpha and PPARbeta mRNA levels were higher in XLH1 at day 45, and PPARbeta and gamma mRNA levels were higher in XLH2R at day 118, suggesting possible involvement of PPAR in stimulation of Delta6D expression, when drastic dietary larval conditioning occurred. The low DHA content in the polar lipids (PL) of LH1 and XLH1 revealed an n-3-HUFA deficiency in these groups. Larval conditioning did not affect DHA content in the PL of R-juveniles. The present study showed (i) a persistent Delta6D mRNA enhancement in juveniles pre-conditioned with an n-3 HUFA-deficient larval diet, over the 1-month intermediate period, and (ii) brought new findings suggesting the involvement of PPAR in the Delta6D mRNA level stimulation. However, such nutritional conditioning had no significant effect on juvenile growth and lipid composition.
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Trattner S, Kamal-Eldin A, Brännäs E, Moazzami A, Zlabek V, Larsson P, Ruyter B, Gjøen T, Pickova J. Sesamin Supplementation Increases White Muscle Docosahexaenoic Acid (DHA) Levels in Rainbow Trout (Oncorhynchus mykiss) Fed High Alpha-Linolenic Acid (ALA) Containing Vegetable Oil: Metabolic Actions. Lipids 2008; 43:989-97. [DOI: 10.1007/s11745-008-3228-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 08/14/2008] [Indexed: 11/28/2022]
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Drazen JC, Phleger CF, Guest MA, Nichols PD. Lipid, sterols and fatty acid composition of abyssal holothurians and ophiuroids from the North-East Pacific Ocean: Food web implications. Comp Biochem Physiol B Biochem Mol Biol 2008; 151:79-87. [DOI: 10.1016/j.cbpb.2008.05.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2008] [Revised: 05/29/2008] [Accepted: 05/30/2008] [Indexed: 10/22/2022]
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35
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Seierstad SL, Poppe TT, Koppang EO, Svindland A, Rosenlund G, Frøyland L, Larsen S. Influence of dietary lipid composition on cardiac pathology in farmed Atlantic salmon, Salmo salar L. JOURNAL OF FISH DISEASES 2005; 28:677-90. [PMID: 16303029 DOI: 10.1111/j.1365-2761.2005.00671.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The present study investigated the short-term (5 months) effect of replacing dietary marine oils with vegetable oils on the development of arteriosclerotic changes in the heart of Atlantic salmon, Salmo salar. The experiment was performed as a randomized observer-blinded and controlled trial. Farmed Atlantic salmon were randomly sampled from a study population containing 900 individuals. The salmon were divided into three groups and given diets with either 100% fish oil (Diet 1), a 50/50% mixture of fish oil and rapeseed oil (Diet 2) or 100% rapeseed oil (Diet 3). Ten sexually immature salmon from each dietary group were sampled in March and August 2002. Additionally, 47 sexually mature wild salmon were randomly collected in mid-September 2001. Serial histological sections were taken from the bulbus arteriosus and ventricle wall for histopathological evaluation of the coronary arteries and myocardium. No significant differences in mean coronary changes recorded by the main variable 'mean range lesion' (MRL) were detected between the groups in March or August. MRL increased significantly between March and August with Diet 2 (P < 0.01), was nearly significant with Diet 3 (P = 0.06) and was unchanged with Diet 1. This pattern coincided with the Diet 2 group having the highest increase in heart weight. MHC class II immunoreactive cells in the coronary changes were detected in sections from one individual in each group. Heart weight was the most dominant variable in the data set and explained linearly 15.5% of the variation in MRL. Body weight, fish length and heart weight were all significantly, positively and linearly correlated to MRL. The Diet 2 group had the highest growth rate and also exhibited a significant increase in MRL. The possible influence of diet composition on weight gain and MRL needs to be further elucidated. Increase in heart weight seems to be the dominating predictor of the appearance of MRL in Atlantic salmon. However, the present results cannot exclude the possibility that differences in fatty acid composition of fish feed can influence the development of arteriosclerotic changes in Atlantic salmon.
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Affiliation(s)
- S L Seierstad
- Department of Basic Sciences and Aquatic Medicine, The Norwegian School of Veterinary Science, Oslo, Norway.
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36
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Agaba MK, Tocher DR, Zheng X, Dickson CA, Dick JR, Teale AJ. Cloning and functional characterisation of polyunsaturated fatty acid elongases of marine and freshwater teleost fish. Comp Biochem Physiol B Biochem Mol Biol 2005; 142:342-52. [PMID: 16183312 DOI: 10.1016/j.cbpb.2005.08.005] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Revised: 08/22/2005] [Accepted: 08/24/2005] [Indexed: 11/28/2022]
Abstract
Enzymes that lengthen the carbon chain of polyunsaturated fatty acids are key to the biosynthesis of the highly unsaturated fatty acids, arachidonic, eicosapentaenoic and docosahexaenoic acids from linoleic and alpha-linolenic acids. A Mortierella alpina cDNA polyunsaturated fatty acid elongase sequence identified mammalian, amphibian, zebrafish and insect expressed sequence tags (ESTs) in GenBank. Consensus primers were designed in conserved motifs and used to isolate full length cDNA from livers of several fish species by Rapid Amplification of cDNA Ends (RACE). The amplified cDNAs encoded putative open reading frames (ORFs) of 288-294 amino acids that were highly conserved among the fish species. Heterologous expression in yeast, Saccharomyces cerevisiae, demonstrated that all of the ORFs encoded elongases with the ability to lengthen polyunsaturated fatty acid substrates with chain lengths from C18 to C22 and also monounsaturated fatty acids, but not saturated fatty acids. There were differences in the functional competence of the elongases from different fish species. Most of the fish elongases showed a pattern of activity towards different fatty acid substrates in the rank order C18>C20>C22, although the tilapia and turbot elongases had similar activity towards 18:4n-3 and 20:5n-3. The fish elongases generally showed greater activity or similar activities with n-3 than with n-6 homologues, with the exception of the cod enzyme which was more active towards n-6 fatty acids.
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Affiliation(s)
- Morris K Agaba
- Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, United Kingdom
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37
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Mansour MP, Holdsworth DG, Forbes SE, Macleod CK, Volkman JK. High contents of 24:6(n-3) and 20:1(n-13) fatty acids in the brittle star Amphiura elandiformis from Tasmanian coastal sediments. BIOCHEM SYST ECOL 2005. [DOI: 10.1016/j.bse.2004.12.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Meyer A, Kirsch H, Domergue F, Abbadi A, Sperling P, Bauer J, Cirpus P, Zank TK, Moreau H, Roscoe TJ, Zähringer U, Heinz E. Novel fatty acid elongases and their use for the reconstitution of docosahexaenoic acid biosynthesis. J Lipid Res 2004; 45:1899-909. [PMID: 15292371 DOI: 10.1194/jlr.m400181-jlr200] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In algae, the biosynthesis of docosahexaenoic acid (22:6omega3; DHA) proceeds via the elongation of eicosapentaenoic acid (20:5omega3; EPA) to 22:5omega3, which is required as a substrate for the final Delta4 desaturation. To isolate the elongase specific for this step, we searched expressed sequence tag and genomic databases from the algae Ostreococcus tauri and Thalassiosira pseudonana, from the fish Oncorhynchus mykiss, from the frog Xenopus laevis, and from the sea squirt Ciona intestinalis using as a query the elongase sequence PpPSE1 from the moss Physcomitrella patens. The open reading frames of the identified elongase candidates were expressed in yeast for functional characterization. By this, we identified two types of elongases from O. tauri and T. pseudonana: one specific for the elongation of (Delta6-)C18-PUFAs and one specific for (Delta5-)C20-PUFAs, showing highest activity with EPA. The clones isolated from O. mykiss, X. laevis, and C. intestinalis accepted both C18- and C20-PUFAs. By coexpression of the Delta6- and Delta5-elongases from T. pseudonana and O. tauri, respectively, with the Delta5- and Delta4-desaturases from two other algae we successfully implemented DHA synthesis in stearidonic acid-fed yeast. This may be considered an encouraging first step in future efforts to implement this biosynthetic sequence into transgenic oilseed crops.
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Affiliation(s)
- Astrid Meyer
- Biozentrum Klein Flottbek, Universität Hamburg, D-22609 Hamburg, Germany
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Zheng X, Seiliez I, Hastings N, Tocher DR, Panserat S, Dickson CA, Bergot P, Teale AJ. Characterization and comparison of fatty acyl Δ6 desaturase cDNAs from freshwater and marine teleost fish species. Comp Biochem Physiol B Biochem Mol Biol 2004; 139:269-79. [PMID: 15465674 DOI: 10.1016/j.cbpc.2004.08.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 07/30/2004] [Accepted: 08/03/2004] [Indexed: 10/26/2022]
Abstract
Fish are the most important dietary source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), that have particularly important roles in human nutrition reflecting their roles in critical physiological processes. The objective of the study described here was to clone, functionally characterize and compare expressed fatty acid desaturase genes involved in the production of EPA and DHA in freshwater and marine teleost fish species. Putative fatty acid desaturase cDNAs were isolated and cloned from common carp (Cyprinus carpio) and turbot (Psetta maximus). The enzymic activities of the products of these cDNAs, together with those of cDNAs previously cloned from rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata), were determined by heterologous expression in the yeast Saccharomyces cerevisiae. The carp and turbot desaturase cDNAs included open reading frames (ORFs) of 1335 and 1338 base pairs, respectively, specifying proteins of 444 and 445 amino acids. The protein sequences possessed all the characteristic features of microsomal fatty acid desaturases, including three histidine boxes, two transmembrane regions, and N-terminal cytochrome b(5) domains containing the haem-binding motif, HPGG. Functional expression showed all four fish cDNAs encode basically unifunctional Delta6 fatty acid desaturase enzymes responsible for the first and rate-limiting step in the biosynthesis of HUFA from 18:3n-3 and 18:2n-6. All the fish desaturases were more active towards the n-3 substrate with 59.5%, 31.5%, 23.1% and 7.0% of 18:3n-3 being converted to 18:4n-3 in the case of turbot, trout, sea bream and carp, respectively. The enzymes also showed very low, probably physiologically insignificant, levels of Delta5 desaturase activity, but none of the products showed Delta4 desaturase activity. The cloning and characterization of desaturases from these fish is an important advance, as they are species in which there is a relative wealth of data on the nutritional regulation of fatty acid desaturation and HUFA synthesis, and between which substantive differences occur.
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Affiliation(s)
- X Zheng
- Institute of Aquaculture, University of Stirling, Airthrey Road, Stirling FK9 4LA, Scotland, United Kingdom
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40
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Hastings N, Agaba MK, Tocher DR, Zheng X, Dickson CA, Dick JR, Teale AJ. Molecular cloning and functional characterization of fatty acyl desaturase and elongase cDNAs involved in the production of eicosapentaenoic and docosahexaenoic acids from alpha-linolenic acid in Atlantic salmon (Salmo salar). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2004; 6:463-74. [PMID: 15549653 DOI: 10.1007/s10126-004-3002-8] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2003] [Accepted: 01/15/2004] [Indexed: 05/09/2023]
Abstract
Fish are the only major dietary source for humans of omega-3 highly unsaturated fatty acids (HUFAs) and with declining fisheries farmed fish such as Atlantic salmon (Salmo salar) constitute an increasing proportion of the fish in the human diet. However, the current high use of fish oils, derived from wild capture marine fisheries, in aquaculture feeds is not sustainable in the longer term and will constrain continuing growth of aquaculture activities. Greater understanding of how fish metabolize and biosynthesize HUFA may lead to more sustainable aquaculture diets. The study described here contributes to an effort to determine the molecular genetics of the HUFA biosynthetic pathway in salmon, with the overall aim being to determine mechanisms for optimizing the use of vegetable oils in Atlantic salmon culture. In this paper we describe the cloning and functional characterization of 2 genes from salmon involved in the biosynthesis of HUFA. A salmon desaturase complementary DNA, SalDes, was isolated that include an open reading frame of 1362 bp specifying a protein of 454 amino acids. The protein sequence includes all the characteristics of microsomal fatty acid desaturases, including 3 histidine boxes, 2 transmembrane regions, and an N-terminal cytochrome b(5) domain containing a heme-binding motif similar to that of other fatty acid desaturases. Functional expression in the yeast Saccharomyces cerevisiae showed SalDes is predominantly an omega-3 delta5 desaturase, a key enzyme in the synthesis of eicosapentaenoic acid (20:5n-3) from alpha-linolenic acid (18:3n-3). The desaturase showed only low levels of delta6 activity toward C(18) polyunsaturated fatty acids. In addition, a fatty acid elongase cDNA, SalElo, was isolated that included an open reading frame of 888 bp, specifying a protein of 295 amino acids. The protein sequence of SalElo included characteristics of microsomal fatty acid elongases, including a histidine box and a transmembrane region. Upon expression in yeast SalElo showed broad substrate specificity for polyunsaturated fatty acids with a range of chain lengths, with the rank order being C(18) > C(20) > C(22). Thus this one polypeptide product displays all fatty acid elongase activities required for the biosynthesis of docosahexaenoic acid (22:6n-3) from 18:3n-3.
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Affiliation(s)
- Nicola Hastings
- Institute of Aquaculture, University of Stirling, FK9 4LA, Scotland, UK
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41
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Rodríguez C, Pérez JA, Henderson RJ. The esterification and modification of n-3 and n-6 polyunsaturated fatty acids by hepatocytes and liver microsomes of turbot (Scophthalmus maximus). Comp Biochem Physiol B Biochem Mol Biol 2002; 132:559-70. [PMID: 12091101 DOI: 10.1016/s1096-4959(02)00072-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study was undertaken to establish whether the formation of 22:6n-3 from 18:3n-3 and/or 20:5n-3 can occur in turbot liver and if this conversion is consistent with the operation of a Delta4 desaturase-independent pathway. At the same, time the effects of feeding a diet devoid of long chain polyunsaturated fatty acids (PUFA) on the patterns of esterification and modification of 18:3n-3, 20:5n-3 and 18:2n-6 by turbot hepatocytes and liver microsomes were examined. For this purpose, two groups of fish (25-30 g) were employed: one was fed a commercial diet containing fish oil (FO) and thus rich in long chain n-3 PUFA and the other was fed an experimental diet based on olive oil (OO). After 5 months of feeding, hepatocytes and liver microsomes isolated from individuals in the two groups of fish were incubated with [1-(14)C]-PUFA [either 18:3n-3, 20:5n-3 or 18:2n-6]. After 3 h of incubation, most radioactivity from all three radiolabelled substrates incorporated into lipids by hepatocytes and microsomes was recovered in the original substrate. The formation of desaturation products of n-3 radiolabelled substrates was higher in hepatocytes isolated from OO-fed than FO-fed fish. Small amounts of radiolabelled 22:6n-3 were formed from [1-(14)C]18:3n-3 and [1-(14)C]20:5n-3, but only by hepatocytes from fish fed OO, which also synthesised a small amount of radiolabelled 24:6n-3 from 14C-20:5n-3. Elongation products predominated over desaturation products in hepatic microsomes from both groups of fish studied, particularly in microsomes from fish fed FO. The results confirm that regardless of the long chain PUFA content of the diet, the production of 22:6n-3 in turbot liver from 18:3n-3 and/or 20:5n-3, and of 20:4n-6 from 18:2n-6, is very limited. The presence of radiolabelled 24:6n-3 in microsomes coupled with the absence of radiolabelled 22:6n-3 suggests that the formation of 22:6n-3 that does occur in turbot liver cells, may involve C24 intermediates and peroxisomal beta-oxidation.
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Affiliation(s)
- Covadonga Rodríguez
- Departamento de Biología Animal (U.D.I. Fisiología), Facultad de Biología, Universidad de La Laguna. 38206 La Laguna, Tenerife, Spain.
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42
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Bell JG, McEvoy J, Tocher DR, McGhee F, Campbell PJ, Sargent JR. Replacement of fish oil with rapeseed oil in diets of Atlantic salmon (Salmo salar) affects tissue lipid compositions and hepatocyte fatty acid metabolism. J Nutr 2001; 131:1535-43. [PMID: 11340112 DOI: 10.1093/jn/131.5.1535] [Citation(s) in RCA: 498] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Duplicate groups of Atlantic salmon post-smolts were fed five practical-type diets in which the added lipid was 100% fish oil [FO; 0% rapeseed oil (0% RO)], 90% FO + 10% RO (10% RO), 75% FO + 25% RO (25% RO), 50% FO + 50% RO (50% RO) or 100% RO, for a period of 17 wk. There were no effects of diet on growth rate or feed conversion nor were any histopathological lesions found in liver, heart, muscle or kidney. The greatest accumulation of muscle lipid was in fish fed 0% RO, which corresponded to significantly lower muscle protein in this group. The highest lipid levels in liver were found in fish fed 100% RO. Fatty acid compositions of muscle lipid correlated with RO inclusion in that the proportions of 18:1(n-9), 18:2(n-6) and 18:3(n-3) all increased with increasing dietary RO (r = 0.98-1.00, P < 0.013). The concentrations of eicosapentaenoic acid [20:5(n-3)] and docosahexaenoic acid [22:6(n-3)] in muscle lipid were significantly reduced (P < 0.05), along with total saturated fatty acids, with increasing dietary RO. Diet-induced changes in liver fatty acid compositions were broadly similar to those in muscle. Hepatic fatty acid desaturation and elongation activities, measured using [1-(14)C] 18:3(n-3), were increased with increasing dietary RO. Limited supplies of marine fish oils require that substitutes be found if growth in aquaculture is to be maintained such that fish health and product quality are not compromised. Thus, RO can be used successfully as a substitute for fish oil in the culture of Atlantic salmon in sea water although at levels of RO >50% of dietary lipid, substantial reductions occur in muscle 20:5(n-3), 22:6(n-3) and the (n-3)/(n-6) polyunsaturated fatty acid (PUFA) ratio, which will result in reduced availability of the (n-3) highly unsaturated fatty acids that are beneficial for human health.
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Affiliation(s)
- J G Bell
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, Scotland, UK
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43
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Wilson R, Sargent JR. Chain separation of monounsaturated fatty acid methyl esters by argentation thin-layer chromatography. J Chromatogr A 2001; 905:251-7. [PMID: 11206792 DOI: 10.1016/s0021-9673(00)01006-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A technique for separating methyl esters of monounsaturated fatty acids by argentation chromatography using silver nitrate-impregnated TLC plates is described. Monounsaturated fatty acid methyl esters are separated from polyunsaturated and saturated fatty acid methyl esters and the monounsaturated fatty methyl esters are resolved according to chain length. cis isomers are well resolved from the corresponding trans isomers. R(F) values for individual monounsaturated fatty acids are very reproducible. The potential of the technique in metabolic studies is demonstrated in the chain elongation of [14C]-18:1(n-9) and delta-9 desaturation of [14C]-18:0 by human skin fibroblasts. Recoveries of individual [14C]-fatty acids for scintillation counting exceed 94%.
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Affiliation(s)
- R Wilson
- Cardiovascular Research Unit, University of Edinburgh, UK.
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44
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Ruyter B, Thomassen MS. Metabolism of n-3 and n-6 fatty acids in Atlantic salmon liver: stimulation by essential fatty acid deficiency. Lipids 1999; 34:1167-76. [PMID: 10606039 DOI: 10.1007/s11745-999-0468-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Oxidation, esterification, desaturation, and elongation of [1-14C]18:2n-6 and [1-14C]18:3n-3 were studied using hepatocytes from Atlantic salmon (Salmo salar L.) maintained on diets deficient in n-3 and n-6 polyunsaturated fatty acids (PUFA) or supplemented with n-3 PUFA. For both dietary groups, radioactivity from 18:3n-3 was incorporated into lipid fractions two to three times faster than from 18:2n-6, and essential fatty acids (EFA) deficiency doubled the incorporation. Oxidation to CO2 was very low and was independent of substrate or diet, whereas oxidation to acid-soluble products was stimulated by EFA deficiency. Products from 18:2n-6 were mainly 18:3n-6, 20:3n-6, and 20:4n-6, with minor amounts of 20:2n-6 and 22:5n-6. Products from 18:3n-3 were mainly 18:4n-3, 20:5n-3, and 22:6n-3, with small amounts of 20:3n-3. The percentage of 22:6n-3 in the polar lipid fraction of EFA-deficient hepatocytes was fourfold higher than in n-3 PUFA-supplemented cells. This correlated well with our other results obtained after abdominal injection of [1-14C]18:3n-3 and [1-14C]18:2n-6. In hepatocytes incubated with [4,5-3H]-22:6n-3, 20:5n-3 was the main product. This retroconversion was increased by EFA deficiency, as was peroxisomal betaoxidation activity. This study shows that 18:2n-6 and 18:3n-3 can be elongated and desaturated in Atlantic salmon liver, and that this conversion and the activity of retroconversion of very long chain PUFA is markedly enhanced by EFA deficiency.
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Affiliation(s)
- B Ruyter
- AKVAFORSK, Institute of Aquaculture Research, As Norway.
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45
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Tocher DR, Leaver MJ, Hodgson PA. Recent advances in the biochemistry and molecular biology of fatty acyl desaturases. Prog Lipid Res 1998; 37:73-117. [PMID: 9829122 DOI: 10.1016/s0163-7827(98)00005-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- D R Tocher
- NERC Unit of Aquatic Biochemistry, School of Natural Sciences, University of Stirling, Scotland, U.K
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46
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Henderson RJ, Burkow IC, Buzzi M, Bayer A. Effects of docosahexaenoic (22:6n-3), tetracosapentaenoic (24:5n-3) and tetracosahexaenoic (24:6n-3) acids on the desaturation and elongation of n-3 polyunsaturated fatty acids in trout liver microsomes. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1392:309-19. [PMID: 9630696 DOI: 10.1016/s0005-2760(98)00045-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The effects of long chain n-3 polyunsaturated fatty acids (PUFA) on the desaturation and elongation systems involved in the conversion of 18:3n-3 to 24:6n-3 were investigated. Microsomes were prepared from the livers of rainbow trout and incubated with 14C-labelled 18:3n-3 and cofactors required for elongation and/or desaturation in the presence of 22:6n-3, 24:5n-3 or 24:6n-3. The formation of 24:6n-3 was significantly inhibited in the presence of 50 microM 22:6n-3, 24:5n-3 or 24:6n-3, whereas the amount of radiolabelled 20:5n-3 formed was inhibited by only 24:5n-3 or 24:6n-3 at the same concentration. When malonyl-CoA was omitted from the incubation system to allow the measurement of desaturation in the absence of elongation, the Delta6 desaturation of 14C-18:3n-3 to 14C-18:4n-3 was inhibited by approximately 25% in the presence of 24:5n-3 or 24:6n-3 but was not affected by 22:6n-3. The Delta5 desaturation of 14C-20:4n-3 was not affected by the presence of any of the long chain PUFA and no significant effect of 18:3n-3, 22:6n-3 or 24:6n-3 on the Delta6 desaturation of 24:5n-3 to 24:6n-3 was observed. To permit the measurement of individual elongation reactions, KCN was included in the incubation medium to inhibit desaturation and 14C-labelled 18:3n-3, 18:4n-3, 20:4n-3, 20:5n-3 and 22:5n-3 were examined as substrates. 18:4n-3 and 22:5n-3 were more extensively used for elongation than 18:3n-3, 20:4n-3 and 20:5n-3. The presence of 22:6n-3, 24:5n-3 or 24:6n-3 in the incubation system had no effect on any of the specific elongations of any of the substrates examined. It is concluded that, in the conversion of 18:3n-3 to 24:6n-3 by trout liver microsomes, the Delta6 desaturation of 18:3n-3 may be subjected to direct feedback inhibition and that 24:5n-3 may be preferred over 18:3n-3 as a substrate for Delta6 desaturation.
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Affiliation(s)
- R J Henderson
- NERC Unit of Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Stirling FK9 4LA, Scotland,
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47
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Bell JG, Tocher DR, Farndale BM, Sargent JR. Growth, mortality, tissue histopathology and fatty acid compositions, eicosanoid production and response to stress, in juvenile turbot fed diets rich in gamma-linolenic acid in combination with eicosapentaenoic acid or docosahexaenoic acid. Prostaglandins Leukot Essent Fatty Acids 1998; 58:353-64. [PMID: 9690713 DOI: 10.1016/s0952-3278(98)90071-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three diets containing either borage oil (BO) and southern hemisphere fish oil Marinol (MO), or BO and tuna orbital oil (TO), or a northern hemisphere fish oil (FO) were fed to duplicate groups of turbot (Scophthalmus maximus) of initial mean weight 1.2 g for a period of 12 weeks. The BO/MO and BO/TO diets were enriched in gamma-linolenic (18:3n-6, GLA) and eicosapentaenoic (20:5n-3, EPA) acids, and GLA and docosahexaenoic acid (22:6n-3, DHA), respectively. No differences were observed in final weights or growth rates, either between duplicate tanks or between dietary treatments. Half of the FO-fed fish sampled showed a histopathological lesion indicative of lipoid liver degeneration while the other treatments only showed a slight incidence of the same pathology. The fatty acid compositions of carcass and tissues broadly reflected the dietary input. In general, fish fed the BO/MO diet had increased levels of 18:2n-6, 18:3n-6, 20:3n-6 and 20:5n-3, but a lower level of 22:6n-3, compared to fish fed FO. In fish fed the BO/TO diet, levels of 18:2n-6, 18:3n-6, 20:3n-6 and 20:4n-6 were increased while levels of 20:5n-3 and 22:5n-3 were reduced, compared to fish fed FO. Concentrations of thromboxanes B (TXB) and leukotrienes B (LTB), derived from 20:4n-6 and 20:5n-3, were measured in plasma and stimulated blood cells. Levels of TXB2 were greatest in fish fed the BO/TO diet compared to both other treatments, while LTB4 was decreased in fish fed the BO/MO diet compared to both other treatments. In a stress test which involved anaesthesia followed by measurement of recovery times, fish fed the BO/MO diet had significantly lower recovery times compared to fish fed the FO diet.
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Affiliation(s)
- J G Bell
- Department of Biological and Molecular Sciences, University of Stirling, UK
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48
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Buzzi M, Henderson RJ, Sargent JR. The biosynthesis of docosahexaenoic acid [22:6(n-3)] from linolenic acid in primary hepatocytes isolated from wild northern pike. JOURNAL OF FISH BIOLOGY 1997; 51:1197-1208. [PMID: 29991167 DOI: 10.1111/j.1095-8649.1997.tb01136.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/1997] [Accepted: 06/26/1997] [Indexed: 06/08/2023]
Abstract
Primary hepatocytes from wild northern pike Esox lucius were incubated with radiolabelled linolenic acid ([l-14 C]-18:3(n-3)) to assess their ability to synthesize docosahexaenoic acid [22:6(n-3)]. The distribution of radioactivity in lipid classes and hepatocyte polyunsaturated fatty acids (PUFA) was measured over the time-course of 24h. The majority of radioactivity from [l-14 C]-18:3(n-3) was recovered in hepatocyte triacylglycerols (TAG) and phosphatidylcholine (PC). The levels of radioactivity in TAG and in most of phospholipids, including PC, increased significantly over the incubation period. Radioactivity from [1-14 C]-18:3(n-3) was recovered in several hepatocyte PUFA, including 22:6(n-3), and the Δ6 and Δ5-desaturation products 18:4(n-3) and 20:5(n-3). The presence of radioactivity in C24 (n-3) PUFA may be evidence that the biosynthesis of 22:6(n-3) in pike proceeds via a pathway independent of Δ4-desaturation. Analysis by radio gas chromatography revealed that radiolabelled 24:6(n-3) was present among the desaturation and elongation products of [l-14 C]-18:3(n-3). The results establish that, under the in vitro conditions employed, pike hepatocytes are able to convert linolenic acid to 20:5(n-3) and 22:6(n-3).
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Affiliation(s)
- M Buzzi
- NERC Unit of Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, U.K
| | - R J Henderson
- NERC Unit of Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, U.K
| | - J R Sargent
- NERC Unit of Aquatic Biochemistry, Department of Biological and Molecular Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, U.K
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