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Zhao B, Peng Y, Itakura Y, Lizanda M, Haga Y, Satoh S, Navarro JC, Monroig Ó, Kabeya N. A complete biosynthetic pathway of the long-chain polyunsaturated fatty acids in an amphidromous fish, ayu sweetfish Plecoglossus altivelis (Stomiati; Osmeriformes). Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159498. [PMID: 38703945 DOI: 10.1016/j.bbalip.2024.159498] [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: 01/09/2024] [Revised: 03/15/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
The biosynthetic capability of the long-chain polyunsaturated fatty acids (LC-PUFA) in teleosts are highly diversified due to evolutionary events such as gene loss and subsequent neo- and/or sub-functionalisation of enzymes encoded by existing genes. In the present study, we have comprehensively characterised genes potentially involved in LC-PUFA biosynthesis, namely one front-end desaturase (fads2) and eight fatty acid elongases (elovl1a, elovl1b, elovl4a, elovl4b, elovl5, elovl7, elovl8a and elovl8b) from an amphidromous teleost, Ayu sweetfish, Plecoglossus altivelis. Functional analysis confirmed Fads2 with Δ6, Δ5 and Δ8 desaturase activities towards multiple PUFA substrates and several Elovl enzymes exhibited elongation capacities towards C18-20 or C18-22 PUFA substrates. Consequently, P. altivelis possesses a complete enzymatic capability to synthesise physiologically important LC-PUFA including arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) from their C18 precursors. Interestingly, the loss of elovl2 gene in P. altivelis was corroborated by genomic and phylogenetic analyses. However, this constraint would possibly be overcome by the function of alternative Elovl enzymes, such as Elovl1b, which has not hitherto been functionally characterised in teleosts. The present study contributes novel insights into LC-PUFA biosynthesis in the relatively understudied teleost group, Osmeriformes (Stomiati), thereby enhancing our understanding of the complement of LC-PUFA biosynthetic genes within teleosts.
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Affiliation(s)
- Bo Zhao
- College of Fisheries, Zhejiang Ocean University, No. 1 Haida South Road, Dinghai District, Zhoushan 316022, Zhejiang Province, China
| | - Yingying Peng
- Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Yuki Itakura
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Myriam Lizanda
- Instituto de Acuicultura Torre de la Sal (IATS), CSIC, Ribera de Cabanes 12595, Castellón, Spain
| | - Yutaka Haga
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Shuichi Satoh
- Department of Advanced Aquaculture Science, Fukui Prefectural University, Katsumi, 49-8-2 Obama, Fukui 917-0116, 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
| | - Naoki Kabeya
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan.
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You C, Miao S, Xie Z, Lin S, Wang S, Chen C, Lin L, Huang Y, Zhou M, Dong Y, Li Y, Zhuang P. Cloning, tissue specificity and regulation of expression of genes of four key enzymes related to long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis by ambient salinity during embryogenesis in the marine teleost Siganus guttatus. Comp Biochem Physiol B Biochem Mol Biol 2024; 269:110903. [PMID: 37717849 DOI: 10.1016/j.cbpb.2023.110903] [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: 06/14/2023] [Revised: 09/10/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023]
Abstract
The rabbitfish Siganus canaliculatus was the first marine teleost reported to possess long-chain polyunsaturated fatty acid (LC-PUFA) biosynthetic ability, and the related molecular mechanisms have been well clarified. Here, we investigated the LC-PUFA biosynthesis capability of the congeneric rabbitfish S. guttatus. First, cDNAs of genes for four key enzymes related to LC-PUFA biosynthesis, namely Δ6Δ5 fatty acyl desaturase (fads2) (1335 bp; 445 aa), Δ4 fads2 (1335 bp; 445 aa), and elongation of very long chain fatty acid proteins (elovl5) (873 bp; 291 aa) and elovl4 (906 bp; 302 aa) were cloned from the liver of S. guttatus. The Δ6Δ5 fads2, Δ4 fads2 and elovl5 genes showed high expression in brain, liver, spleen, gallbladder, and intestine but relatively low expression in eye, whereas the elovl4 gene showed specific and high expression in eye. During embryogenesis, mRNA expression of Δ4 fads2 and elovl4 was detected from 8 h post-fertilization (hpf) and then maintained a high level to 24 hpf, while mRNA expression of Δ6Δ5 fads2 and elovl5 reached a peak at 14 hpf but then declined. In addition, ambient salinity (32 ppt and 20 ppt) exerted some regulatory influence on the expression of the four genes during embryogenesis. The levels of C18 PUFA precursors and, especially, PUFA and DHA of the embryos, decreased from 17 hpf to 24 hpf. These results suggested that S. guttatus, similar to the congeneric S. canaliculatus, would have capability for LC-PUFA biosynthesis, which is still not activated at the fertilized egg stage.
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Affiliation(s)
- Cuihong You
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Shuangshuang Miao
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Zhiyong Xie
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Siyuan Lin
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Shuqi Wang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Cuiying Chen
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou 515063, Guangdong, China
| | - Li Lin
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China
| | - Yanhua Huang
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China
| | - Meng Zhou
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China
| | - Yewei Dong
- Innovative Institute of Animal Healthy Breeding, Guangzhou Key Laboratory of Aquatic Animal Diseases and Waterfowl Breeding, College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510222, Guangdong, China.
| | - Yuanyou Li
- College of Marine Sciences & University Joint Laboratory of Guangdong Province, Hong Kong and Macao Region on MBCE, South China Agricultural University, Guangzhou 510642, China.
| | - Ping Zhuang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
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Østbye TKK, Gudbrandsen OA, Drotningsvik A, Ruyter B, Berge GM, Vogt G, Nilsson A. Different Dietary Ratios of Camelina Oil to Sandeel Oil Influence the Capacity to Synthesise and Deposit EPA and DHA in Zucker Fa/Fa Rats. Nutrients 2023; 15:nu15102344. [PMID: 37242227 DOI: 10.3390/nu15102344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
Plant-based food provides more ALA (α-linolenic acid) and less EPA (eicosapentaenoic acid) and DHA (docosahexanoic acid) than marine food. Earlier studies indicate that cetoleic acid (22:1n-11) stimulates the n-3 pathway from ALA to EPA and DHA. The present study aimed to investigate the dietary effects of camelina oil (CA) high in ALA and sandeel oil (SA) high in cetoleic acid on the conversion of ALA to EPA and DHA. Male Zucker fa/fa rats were fed a diet of soybean oil (Ctrl) or diets of CA, SA, or a combination of CA and SA. Significantly higher levels of DPA (docosapentaenoic acid) and DHA in blood cells from the CA group compared to the Ctrl indicate an active conversion of ALA to DPA and DHA. Increasing the uptake and deposition of EPA and DHA meant that a trend towards a decrease in the liver gene expression of Elovl5, Fads1, and Fads2 along with an increase in the dietary content of SA was observed. However, 25% of the SA could be exchanged with CA without having a significant effect on EPA, DPA, or DHA in blood cells, indicating that bioactive components in SA, such as cetoleic acid, might counteract the inhibiting effect of the high dietary content of DHA on the n-3 biosynthetic pathway.
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Affiliation(s)
| | - Oddrun Anita Gudbrandsen
- Dietary Research Group, Centre for Nutrition, Department of Clinical Medicine, University of Bergen, 5007 Bergen, Norway
| | - Aslaug Drotningsvik
- Dietary Research Group, Centre for Nutrition, Department of Clinical Medicine, University of Bergen, 5007 Bergen, Norway
- Vedde AS, 6030 Langevåg, Norway
| | - Bente Ruyter
- Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research, 1433 Ås, Norway
| | - Gerd Marit Berge
- Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research, 1433 Ås, Norway
| | - Gjermund Vogt
- Eurofins Food & Agro Testing Norway AS, 1538 Moss, Norway
| | - Astrid Nilsson
- Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research, 1433 Ås, Norway
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Long-term feeding of Atlantic salmon with varying levels of dietary EPA + DHA alters the mineral status but does not affect the stress responses after mechanical delousing stress. Br J Nutr 2022; 128:2291-2307. [PMID: 35156914 PMCID: PMC9723492 DOI: 10.1017/s0007114522000514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Atlantic salmon were fed diets containing graded levels of EPA + DHA (1·0, 1·3, 1·6 and 3·5 % in the diet) and one diet with 1·3 % of EPA + DHA with reduced total fat content. Fish were reared in sea cages from about 275 g until harvest size (about 5 kg) and were subjected to delousing procedure (about 2·5 kg), with sampling pre-, 1 h and 24 h post-stress. Delousing stress affected plasma cortisol and hepatic mRNA expression of genes involved in oxidative stress and immune response, but with no dietary effects. Increasing EPA + DHA levels in the diet increased the trace mineral levels in plasma and liver during mechanical delousing stress period and whole body at harvest size. The liver Se, Zn, Fe, Cu, and Mn and plasma Se levels were increased in fish fed a diet high in EPA + DHA (3·5 %) upon delousing stress. Furthermore, increased dietary EPA + DHA caused a significant increase in mRNA expression of hepcidin antimicrobial peptide (HAMP), which is concurrent with downregulated transferrin receptor (TFR) expression levels. High dietary EPA + DHA also significantly increased the whole-body Zn, Se, and Mn levels at harvest size fish. Additionally, the plasma and whole-body Zn status increased, respectively, during stress and at harvest size in fish fed reduced-fat diet with less EPA + DHA. As the dietary upper limits of Zn and Se are legally added to the feeds and play important roles in maintaining fish health, knowledge on how the dietary fatty acid composition and lipid level affect body stores of these minerals is crucial for the aquaculture industry.
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Datsomor AK, Gillard G, Jin Y, Olsen RE, Sandve SR. Molecular Regulation of Biosynthesis of Long Chain Polyunsaturated Fatty Acids in Atlantic Salmon. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:661-670. [PMID: 35907166 PMCID: PMC9385821 DOI: 10.1007/s10126-022-10144-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Salmon is a rich source of health-promoting omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). The LC-PUFA biosynthetic pathway in Atlantic salmon is one of the most studied compared to other teleosts. This has largely been due to the massive replacement of LC-PUFA-rich ingredients in aquafeeds with terrestrial plant oils devoid of these essential fatty acids (EFA) which ultimately pushed dietary content towards the minimal requirement of EFA. The practice would also reduce tissue content of n-3 LC-PUFA compromising the nutritional value of salmon to the human consumer. These necessitated detailed studies of endogenous biosynthetic capability as a contributor to these EFA. This review seeks to provide a comprehensive and concise overview of the current knowledge about the molecular genetics of PUFA biosynthesis in Atlantic salmon, highlighting the enzymology and nutritional regulation as well as transcriptional control networks. Furthermore, we discuss the impact of genome duplication on the complexity of salmon LC-PUFA pathway and highlight probable implications on endogenous biosynthetic capabilities. Finally, we have also compiled and made available a large RNAseq dataset from 316 salmon liver samples together with an R-script visualization resource to aid in explorative and hypothesis-driven research into salmon lipid metabolism.
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Affiliation(s)
- Alex K. Datsomor
- Center for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Gareth Gillard
- Center for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Yang Jin
- Center for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Rolf E. Olsen
- Institute of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Simen R. Sandve
- Center for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
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Sam KK, Lau NS, Kuah MK, Lading EA, Shu-Chien AC. A complete inventory of long-chain polyunsaturated fatty acid biosynthesis pathway enzymes in the miniaturized cyprinid Paedocypris micromegethes. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:817-838. [PMID: 35643977 DOI: 10.1007/s10695-022-01082-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
The capacity for long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis activity in a species depends on the enzymatic activities of fatty acyl desaturase (Fads) and elongation of very long-chain fatty acid (Elovl). The miniaturized fish Paedocypris micromegethes is a developmentally truncated cyprinid living in highly acidic water conditions in tropical peat swamps. The capacity for LC-PUFA biosynthesis in this species, which has a reduced genome size, is unknown. A high-quality de novo transcriptome assembly enabled the identification of a putative Fads2 and four Elovl. The Fads2 was verified as a P. micromegethes Fads2 ortholog with in vitro Δ5 and Δ6 activities. The Elovl sequences were established as an Elovl5, Elovl2, and two Elovl4 paralogs, namely Elovl4a and Elovl4b. These Elovl enzymes, mainly Elovl5 and Elovl2, fulfill the necessary C18, C20, and C22 PUFA elongation steps for LC-PUFA biosynthesis. Collectively, these results validate the presence of a complete repertoire of LC-PUFA biosynthesis enzymes in a peat swamp miniatured freshwater fish.
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Affiliation(s)
- Ka-Kei Sam
- Centre for Chemical Biology, Universiti Sains Malaysia, 11900, Bayan Lepas, Penang, Malaysia
| | - Nyok-Sean Lau
- Centre for Chemical Biology, Universiti Sains Malaysia, 11900, Bayan Lepas, Penang, Malaysia
| | - Meng-Kiat Kuah
- Lab-Ind Resource Sdn. Bhd, 48300, Bukit Beruntung, Selangor, Malaysia
| | - Engkamat Anak Lading
- Forest Department Sarawak, Forest Department HQ, Level 11, Baitul Makmur II, Medan Raya, Petra Jaya, 93050, Kuching, Sarawak, Malaysia
| | - Alexander Chong Shu-Chien
- Centre for Chemical Biology, Universiti Sains Malaysia, 11900, Bayan Lepas, Penang, Malaysia.
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Minden, Penang, Malaysia.
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Monroig Ó, Shu-Chien A, Kabeya N, Tocher D, Castro L. Desaturases and elongases involved in long-chain polyunsaturated fatty acid biosynthesis in aquatic animals: From genes to functions. Prog Lipid Res 2022; 86:101157. [DOI: 10.1016/j.plipres.2022.101157] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/17/2021] [Accepted: 01/22/2022] [Indexed: 01/01/2023]
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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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Katan T, Xue X, Caballero-Solares A, Taylor RG, Rise ML, Parrish CC. Influence of Dietary Long-Chain Polyunsaturated Fatty Acids and ω6 to ω3 Ratios on Head Kidney Lipid Composition and Expression of Fatty Acid and Eicosanoid Metabolism Genes in Atlantic Salmon ( Salmo salar). Front Mol Biosci 2020; 7:602587. [PMID: 33381522 PMCID: PMC7767880 DOI: 10.3389/fmolb.2020.602587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/17/2020] [Indexed: 01/01/2023] Open
Abstract
The interaction of dietary eicosapentaenoic acid and docosahexaenoic acid (EPA+DHA) levels with omega-6 to omega-3 ratios (ω6:ω3), and their impact on head kidney lipid metabolism in farmed fish, are not fully elucidated. We investigated the influence of five plant-based diets (12-week exposure) with varying EPA+DHA levels (0.3, 1.0, or 1.4%) and ω6:ω3 (high ω6, high ω3, or balanced) on tissue lipid composition, and transcript expression of genes involved in fatty acid and eicosanoid metabolism in Atlantic salmon head kidney. Tissue fatty acid composition was reflective of the diet with respect to C18 PUFA and MUFA levels (% of total FA), and ω6:ω3 (0.5–1.5). Fish fed 0.3% EPA+DHA with high ω6 (0.3% EPA+DHA↑ω6) had the highest increase in proportions (1.7–2.3-fold) and in concentrations (1.4-1.8-fold) of arachidonic acid (ARA). EPA showed the greatest decrease in proportion and in concentration (by ~½) in the 0.3% EPA+DHA↑ω6 fed fish compared to the other treatments. However, no differences were observed in EPA proportions among salmon fed the high ω3 (0.3 and 1.0% EPA+DHA) and balanced (1.4% EPA+DHA) diets, and DHA proportions were similar among all treatments. Further, the transcript expression of elovl5a was lowest in the 0.3% EPA+DHA↑ω6 fed fish, and correlated positively with 20:3ω3, 20:4ω3 and EPA:ARA in the head kidney. This indicates that high dietary 18:3ω3 promoted the synthesis of ω3 LC-PUFA. Dietary EPA+DHA levels had a positive impact on elovl5a, fadsd5 and srebp1 expression, and these transcripts positively correlated with tissue ΣMUFA. This supported the hypothesis that LC-PUFA synthesis is positively influenced by tissue MUFA levels in Atlantic salmon. The expression of pparaa was higher in the 0.3% EPA+DHA↑ω6 compared to the 0.3% EPA+DHA↑ω3 fed fish. Finally, significant correlations between head kidney fatty acid composition and the expression of eicosanoid synthesis-related transcripts (i.e., 5loxa, 5loxb, cox1, cox2, ptges2, ptges3, and pgds) illustrated the constitutive relationships among fatty acids and eicosanoid metabolism in salmon.
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Affiliation(s)
- Tomer Katan
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Xi Xue
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | | | | | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Christopher C Parrish
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
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10
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Jin Y, Datsomor AK, Olsen RE, Vik JO, Torgersen JS, Edvardsen RB, Wargelius A, Winge P, Grammes F. Targeted mutagenesis of ∆5 and ∆6 fatty acyl desaturases induce dysregulation of lipid metabolism in Atlantic salmon (Salmo salar). BMC Genomics 2020; 21:805. [PMID: 33213387 PMCID: PMC7678299 DOI: 10.1186/s12864-020-07218-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023] Open
Abstract
Background With declining wild fish populations, farmed salmon has gained popularity as a source for healthy long-chain highly unsaturated fatty acids (LC-HUFA). However, the introduction of plant oil in farmed salmon feeds has reduced the content of these beneficial LC-HUFA. The synthetic capability for LC-HUFAs depends upon the dietary precursor fatty acids and the genetic potential, thus there is a need for in-depth understanding of LC-HUFA synthetic genes and their interactions with other genes involved in lipid metabolism. Several key genes of LC-HUFA synthesis in salmon belong to the fatty acid desaturases 2 (fads2) family. The present study applied whole transcriptome analysis on two CRISPR-mutated salmon strains (crispants), 1) Δ6abc/5Mt with mutations in Δ5fads2, Δ6fads2-a, Δ6fads2-b and Δ6fads2-c genes, and 2) Δ6bcMt with mutations in Δ6fads2-b and Δ6fads2-c genes. Our purpose is to evaluate the genetic effect fads2 mutations have on other lipid metabolism pathways in fish, as well as to investigate mosaicism in a commercial species with a very long embryonal period. Results Both Δ6abc/5Mt and Δ6bcMt crispants demonstrated high percentage of indels within all intended target genes, though different indel types and percentage were observed between individuals. The Δ6abc/5Mt fish displayed several disruptive indels which resulted in over 100 differentially expressed genes (DEGs) enriched in lipid metabolism pathways in liver. This includes up-regulation of srebp1 genes which are known key transcription regulators of lipid metabolism as well as a number of down-stream genes involved in fatty acid de-novo synthesis, fatty acid β-oxidation and lipogenesis. Both elovl5 and elovl2 genes were not changed, suggesting that the genes were not targeted by Srebp1. The mutation of Δ6bcMt surprisingly resulted in over 3000 DEGs which were enriched in factors encoding genes involved in mRNA regulation and stability. Conclusions CRISPR-Cas9 can efficiently mutate multiple fads2 genes simultaneously in salmon. The results of the present study have provided new information on the transcriptional regulations of lipid metabolism genes after reduction of LC-HUFA synthesis pathways in salmon. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07218-1.
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Affiliation(s)
- Yang Jin
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432, Aas, Norway
| | - Alex K Datsomor
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Rolf E Olsen
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Jon Olav Vik
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432, Aas, Norway
| | | | | | | | - Per Winge
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Fabian Grammes
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432, Aas, Norway. .,AquaGen AS, Post box 1240, Torgard, N-7462, Trondheim, Norway.
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11
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Sun S, Ren T, Li X, Cao X, Gao J. Polyunsaturated fatty acids synthesized by freshwater fish: A new insight to the roles of elovl2 and elovl5 in vivo. Biochem Biophys Res Commun 2020; 532:414-419. [PMID: 32883522 DOI: 10.1016/j.bbrc.2020.08.074] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 08/19/2020] [Indexed: 12/12/2022]
Abstract
At present, fish provide an important supply of long-chain polyunsaturated fatty acids (LC-PUFAs) for human consumption. Previous studies have shown that fatty acyl elongase 2 (elovl2) and elovl5 play important roles in fish LC-PUFA synthesis. Generally, freshwater fish have a stronger ability to synthesize LC-PUFAs than marine fish. However, the roles of elovl2, elovl5 and elovl2 + elovl5 in LC-PUFA synthesis of freshwater fish in vivo are not very clear. In this study, the elovl2 knockout zebrafish (elovl2-/-), elovl5 knockout zebrafish (elovl5-/-) and the double gene knockout zebrafish (DKO) were generated by CRISPR/Cas9 technology for the first time. Compared with wild type zebrafish (WT), elovl5-deletion zebrafish showed a significant increase in C22 PUFA content, which might be due to the up-regulation expressions of elovl4b and elovl2. elovl5 expressed at very low levels in livers of elovl2-/- relative to WT, indicating that elovl5 may be an "assistant attacker" of elovl2 in LC-PUFA synthesis of zebrafish. Moreover, there were no significant differences in levels of C18-C22 PUFAs between DKO and WT, indicating that besides elovl2 + elovl5 path, LC-PUFA synthesis in zebrafish could be performed by other paths. In addition, the hepatic lipidomic analysis results revealed that the contents of C22:6n-3 in phosphatidyl ethanolamine (PE-DHA) and PE-C22 PUFAs were more easily affected by the absence of elovl2 and elovl5. Our results suggest that the elovl2+elovl5 path is not the only path for LC-PUFA synthesis in zebrafish, and provide novel insights into the roles of elovl2 and elovl5 in LC-PUFA synthesis of freshwater fish.
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Affiliation(s)
- Shouxiang Sun
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - Tianying Ren
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xin Li
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaojuan Cao
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China; College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education/Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jian Gao
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China; College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education/Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan, 430070, China.
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12
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Caballero-Solares A, Xue X, Cleveland BM, Foroutani MB, Parrish CC, Taylor RG, Rise ML. Diet-Induced Physiological Responses in the Liver of Atlantic Salmon (Salmo salar) Inferred Using Multiplex PCR Platforms. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2020; 22:511-525. [PMID: 32495111 PMCID: PMC8346449 DOI: 10.1007/s10126-020-09972-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
The simultaneous quantification of several transcripts via multiplex PCR can accelerate research in fish physiological responses to diet and enable the development of superior aquafeeds for farmed fish. We designed two multiplex PCR panels that included assays for 40 biomarker genes representing key aspects of fish physiology (growth, metabolism, oxidative stress, and inflammation) and 3 normalizer genes. We used both panels to assess the physiological effects of replacing fish meal and fish oil by terrestrial alternatives on Atlantic salmon smolts. In a 14-week trial, we tested three diets based on marine ingredients (MAR), animal by-products and vegetable oil (ABP), and plant protein and vegetable oil (VEG). Dietary treatments affected the expression of genes involved in hepatic glucose and lipid metabolism (e.g., srebp1, elovl2), cell redox status (e.g., txna, prdx1b), and inflammation (e.g., pgds, 5loxa). At the multivariate level, gene expression profiles were more divergent between fish fed the marine and terrestrial diets (MAR vs. ABP/VEG) than between the two terrestrial diets (ABP vs. VEG). Liver ARA was inversely related to glucose metabolism (gck)- and growth (igfbp-5b1, htra1b)-related biomarkers and hepatosomatic index. Liver DHA and EPA levels correlated negatively with elovl2, whereas ARA levels correlated positively with fadsd5. Lower hepatic EPA/ARA in ABP-fed fish correlated with the increased expression of biomarkers related to mitochondrial function (fabp3a), oxidative stress (txna, prdx1b), and inflammation (pgds, 5loxa). The analysis of hepatic biomarker gene expression via multiplex PCR revealed potential physiological impacts and nutrient-gene interactions in Atlantic salmon fed lower levels of marine-sourced nutrients.
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Affiliation(s)
- Albert Caballero-Solares
- Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Road, St. John's, NL, A1C 5S7, Canada.
| | - Xi Xue
- Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Road, St. John's, NL, A1C 5S7, Canada
| | - Beth M Cleveland
- National Center for Cool and Cold Water Aquaculture, ARS/USDA, 11861 Leetown Rd, Kearneysville, WV, 25430, USA
| | - Maryam Beheshti Foroutani
- Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Road, St. John's, NL, A1C 5S7, Canada
| | - Christopher C Parrish
- Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Road, St. John's, NL, A1C 5S7, Canada
| | | | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Road, St. John's, NL, A1C 5S7, Canada
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13
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Kida M, Nakamura T, Murata T. A novel eicosapentaenoic acid-derived anti-inflammatory lipid mediator 5,6-DiHETE is abundant in blue back fish intestines. J Food Sci 2020; 85:1983-1987. [PMID: 32572984 DOI: 10.1111/1750-3841.15179] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 04/18/2020] [Accepted: 04/22/2020] [Indexed: 01/03/2023]
Abstract
Because omega-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and their metabolites are known to possess anti-inflammatory and health-promoting functions in human and experimental animals, their intake is assumed to be beneficial for maintaining our health. We previously identified a cytochrome P450-metabolite of EPA, 5,6-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid (5,6-DiHETE), as a novel bioactive lipid, which inhibits vascular hyperpermeability in inflammation. Because blue back fishes including sardine, mackerel, and horse mackerel are reported to contain high concentrations of omega-3 fatty acids, we investigated which tissue of blue back fish is suitable as a source of 5,6-DiHETE. We measured the concentration of 5,6-DiHETE as well as major fatty acids in muscle, bone, heart, liver, and intestine of blue back fishes. Arachidonic acid was detected richer in intestines than other tissues of blue back fishes. The concentrations were between 4.45 and 5.62 µg/g tissue weight. EPA and DHA are also detected richer in intestines of blue back fishes. The concentrations were between 75.95 and 358.04 µg/g, and 203.09 and 464.88 µg/g, respectively. Especially, mackerel intestine contained the highest levels of both EPA and DHA. 5,6-DiHETE was present in greater amount in livers and intestines of blue back fishes. The livers contained 118.98 to 476.11 ng/g, whereas intestines contained 156.14 to 970.22 ng/g of 5,6-DiHETE. Of interest, sardine intestine contained much higher level of 5,6-DiHETE than the other fish tissues. These results suggest that visceral organs of blue back fishes, remarkably sardine intestine, can be a good source of 5,6-DiHETE. PRACTICAL APPLICATION: A novel anti-inflammatory lipid, 5,6-DiHETE, was detected in each tissues of blue back fishes. Especially their intestines contain the highest concentration of this lipid.
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Affiliation(s)
- Misato Kida
- Department of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
| | - Tatsuro Nakamura
- Department of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
| | - Takahisa Murata
- Department of Animal Radiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
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14
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Rivera-Pérez C, Valenzuela-Quiñonez F, Caraveo-Patiño J. Comparative and functional analysis of desaturase FADS1 (∆5) and FADS2 (∆6) orthologues of marine organisms. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 35:100704. [PMID: 32554222 DOI: 10.1016/j.cbd.2020.100704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/02/2020] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
Abstract
Fatty acid desaturases are key enzymes involved in unsaturated fatty acid biosynthesis, which insert double bonds at specific positions of fatty acids, playing a pivotal role in unsaturated fatty acid synthesis required for membrane lipid fluidity. The ∆5 and ∆6 desaturases are responsible for producing long chain-polyunsaturated fatty acids (LC-PUFA) through their precursors α-linolenic acid and linoleic acid in organisms lacking or with very low ability to synthesize LC-PUFA by themselves. Extensive studies of fatty acid desaturases are available in model organisms, such as humans and mouse; however, the diversity of these genes in the marine biodiversity is less known. This study performed an exhaustive analysis to identify the ∆5 and ∆6 desaturases in the available marine genomes in databases, as well as transcriptomes and EST databases, and their coding sequences were compared to the well-characterized ∆5 and ∆6 desaturases from humans. The FADS1 and FADS2 genetic structures are well conserved among all the organisms analyzed. A common amino acid pattern was identified to discriminate between ∆5 and ∆6 desaturases. The analysis of the conserved motif involved in catalysis showed that 20% of the desaturases, ∆5 and ∆6, have lost motifs required for catalysis. Additionally, bifunctional ∆5/∆6 desaturases were able to be identified by amino acid sequence patterns found in previously described enzymes. A revision of the expression profiles and functional activity on sequences in databases and scientific literature provided information regarding the function of these marine organism enzymes.
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Affiliation(s)
| | | | - Javier Caraveo-Patiño
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), La Paz, B.C.S. 23096, Mexico
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15
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Bogevik AS, Hayman ES, Bjerke MT, Dessen JE, Rørvik KA, Luckenbach JA. Phospholipid and LC-PUFA metabolism in Atlantic salmon (Salmo salar) testes during sexual maturation. PLoS One 2020; 15:e0233322. [PMID: 32469895 PMCID: PMC7259613 DOI: 10.1371/journal.pone.0233322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 05/02/2020] [Indexed: 11/19/2022] Open
Abstract
The importance of dietary lipids in male reproduction are not as well understood as in females, in which dietary lipids, such as phospholipids (PL) and associated fatty acids (FA), are important structural components of the eggs and provide energy for their offspring. In mammals, lipids are suggested to be important for spermatogenesis and to structural components of the spermatozoa that could improve fertilization rates. New knowledge of how lipids affect sexual maturation in male Atlantic salmon (Salmo salar), an important global aquaculture species, could provide tools to delay maturation and/or improve reproductive success. Therefore, changes in testicular composition of lipids and gene transcripts associated with spermatogenesis and lipid metabolism were studied in sexually maturing male salmon compared to immature males and females. An increase in total testis content of FA and PL, and a shift to higher PL composition was observed in maturing males, concomitant with increases in mRNA levels for genes involved in spermatogenesis, FA uptake and synthesis, and production of long chain-polyunsaturated fatty acids (LC-PUFA) and PL. A particularly interesting finding was elevated testis expression of acyl-CoA synthetase 4 (acsl4), and acyl-CoA thioesterase 2 (acot2), critical enzymes that regulate intra-mitochondrial levels of 20:4n-6 FA (arachidonic acid), which have been associated with improved cholesterol transport during steroidogenesis. This suggested that FA may have direct effects on sex steroid production in salmon. Furthermore, we observed increased testis expression of genes for endogenous synthesis of 16:0 and elongation/desaturation to 22:6n-3 (docosahexaenoic acid) in sexually maturing males relative to immature fish. Both of these FA are important structural components of the PL, phosphatidylcholine (PC), and were elevated concomitant with increases in the content of phosphatidic acid, an important precursor for PC, in maturing males compared to immature fish. Overall, this study suggests that, similar to mammals, lipids are important to spermatogenesis and serve as structural components during testicular growth and maturation in Atlantic salmon.
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Affiliation(s)
| | - Edward S. Hayman
- Ocean Associates Inc., Under Contract to Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
| | | | | | - Kjell-Arne Rørvik
- Division Aquaculture, Nofima AS, Ås, Norway
- Department of Animal and Aquaculture Sciences, Norwegian University of Life Sciences, Ås, Norway
| | - J. Adam Luckenbach
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
- Center for Reproductive Biology, Washington State University, Pullman, Washington, United States of America
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16
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The catadromous teleost Anguilla japonica has a complete enzymatic repertoire for the biosynthesis of docosahexaenoic acid from α-linolenic acid: Cloning and functional characterization of an Elovl2 elongase. Comp Biochem Physiol B Biochem Mol Biol 2020; 240:110373. [DOI: 10.1016/j.cbpb.2019.110373] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 01/21/2023]
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17
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CRISPR/Cas9-mediated editing of Δ5 and Δ6 desaturases impairs Δ8-desaturation and docosahexaenoic acid synthesis in Atlantic salmon (Salmo salar L.). Sci Rep 2019; 9:16888. [PMID: 31729437 PMCID: PMC6858459 DOI: 10.1038/s41598-019-53316-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 10/26/2019] [Indexed: 01/11/2023] Open
Abstract
The in vivo functions of Atlantic salmon fatty acyl desaturases (fads2), Δ6fads2-a, Δ6fads2-b, Δ6fads2-c and Δ5fads2 in long chain polyunsaturated fatty acid (LC-PUFA) synthesis in salmon and fish in general remains to be elucidated. Here, we investigate in vivo functions and in vivo functional redundancy of salmon fads2 using two CRISPR-mediated partial knockout salmon, Δ6abc/5Mt with mutations in Δ6fads2-a, Δ6fads2-b, Δ6fads2-c and Δ5fads2, and Δ6bcMt with mutations in Δ6fads2-b and Δ6fads2-c. F0 fish displaying high degree of gene editing (50–100%) were fed low LC-PUFA and high LC-PUFA diets, the former containing reduced levels of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids but higher content of linoleic (18:2n-6) and alpha-linolenic (18:3n-3) acids, and the latter containing high levels of 20:5n-3 and 22:6n-3 but reduced compositions of 18:2n-6 and 18:3n-3. The Δ6abc/5Mt showed reduced 22:6n-3 levels and accumulated Δ6-desaturation substrates (18:2n-6, 18:3n-3) and Δ5-desaturation substrate (20:4n-3), demonstrating impaired 22:6n-3 synthesis compared to wildtypes (WT). Δ6bcMt showed no effect on Δ6-desaturation compared to WT, suggesting Δ6 Fads2-a as having the predominant Δ6-desaturation activity in salmon, at least in the tissues analyzed. Both Δ6abc/5Mt and Δ6bcMt demonstrated significant accumulation of Δ8-desaturation substrates (20:2n-6, 20:3n-3) when fed low LC-PUFA diet. Additionally, Δ6abc/5Mt demonstrated significant upregulation of the lipogenic transcription regulator, sterol regulatory element binding protein-1 (srebp-1) in liver and pyloric caeca under reduced dietary LC-PUFA. Our data suggest a combined effect of endogenous LC-PUFA synthesis and dietary LC-PUFA levels on srebp-1 expression which ultimately affects LC-PUFA synthesis in salmon. Our data also suggest Δ8-desaturation activities for salmon Δ6 Fads2 enzymes.
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18
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Irvine NA, Ruyter B, Østbye TK, Sonesson AK, Lillycrop KA, Berge G, Burdge GC. Dietary Fish Oil Alters DNA Methylation of Genes Involved in Polyunsaturated Fatty Acid Biosynthesis in Muscle and Liver of Atlantic Salmon (Salmo salar). Lipids 2019; 54:725-739. [PMID: 31658496 DOI: 10.1002/lipd.12198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 07/16/2019] [Accepted: 09/19/2019] [Indexed: 01/13/2023]
Abstract
Adequate dietary supply of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) is required to maintain health and growth of Atlantic salmon (Salmo salar). However, salmon can also convert α-linolenic acid (18:3n-3) into eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) by sequential desaturation and elongation reactions, which can be modified by 20:5n-3 and 22:6n-3 intake. In mammals, dietary 20:5n-3 + 22:6n-3 intake can modify Fads2 expression (Δ6 desaturase) via altered DNA methylation of its promoter. Decreasing dietary fish oil (FO) has been shown to increase Δ5fad expression in salmon liver. However, it is not known whether this is associated with changes in the DNA methylation of genes involved in polyunsaturated fatty acid synthesis. To address this, we investigated whether changing the proportions of dietary FO and vegetable oil altered the DNA methylation of Δ6fad_b, Δ5fad, Elovl2, and Elovl5_b promoters in liver and muscle from Atlantic salmon and whether any changes were associated with mRNA expression. Higher dietary FO content increased the proportions of 20:5n-3 and 22:6n-3 and decreased Δ6fad_b mRNA expression in liver, but there was no effect on Δ5fad, Elovl2, and Elovl5_b expression. There were significant differences between liver and skeletal muscle in the methylation of individual CpG loci in all four genes studied. Methylation of individual Δ6fad_b CpG loci was negatively related to its expression and to proportions of 20:5n-3 and 22:6n-3 in the liver. These findings suggest variations in dietary FO can induce gene-, CpG locus-, and tissue-related changes in DNA methylation in salmon.
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Affiliation(s)
- Nicola A Irvine
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Bente Ruyter
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), PO Box 210 1432, Ås, Norway
| | - Tone-Kari Østbye
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), PO Box 210 1432, Ås, Norway
| | - Anna K Sonesson
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), PO Box 210 1432, Ås, Norway
| | - Karen A Lillycrop
- Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, UK
| | - Gerd Berge
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), Sjølsengveien 22, 6600 Sunndalsøra, Norway
| | - Graham C Burdge
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
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19
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Deák F, Anderson RE, Fessler JL, Sherry DM. Novel Cellular Functions of Very Long Chain-Fatty Acids: Insight From ELOVL4 Mutations. Front Cell Neurosci 2019; 13:428. [PMID: 31616255 PMCID: PMC6763723 DOI: 10.3389/fncel.2019.00428] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 09/06/2019] [Indexed: 12/22/2022] Open
Abstract
Elongation of Very Long chain fatty acids-4 (ELOVL4) protein is a member of the ELOVL family of fatty acid elongases that is collectively responsible for catalyzing formation of long chain fatty acids. ELOVL4 is the only family member that catalyzes production of Very Long Chain Saturated Fatty Acids (VLC-SFA) and Very Long Chain Polyunsaturated Fatty Acids (VLC-PUFA) with chain lengths ≥28 carbons. ELOVL4 and its VLC-SFA and VLC-PUFA products are emerging as important regulators of synaptic signaling and neuronal survival in the central nervous system (CNS). Distinct sets of mutations in ELOVL4 cause three different neurological diseases in humans. Heterozygous inheritance of one set of autosomal dominant ELOVL4 mutations that leads to truncation of the ELOVL4 protein causes Stargardt-like macular dystrophy (STGD3), an aggressive juvenile-onset retinal degeneration. Heterozygous inheritance of a different set of autosomal dominant ELOVL4 mutations that leads to a full-length protein with single amino acid substitutions causes spinocerebellar ataxia 34 (SCA34), a late-onset neurodegenerative disease characterized by gait ataxia and cerebellar atrophy. Homozygous inheritance of a different set of ELOVL4 mutations causes a more severe disease with infantile onset characterized by seizures, spasticity, intellectual disability, ichthyosis, and premature death. ELOVL4 is expressed widely in the CNS and is found primarily in neurons. ELOVL4 is expressed in cell-specific patterns within different regions of the CNS that are likely to be related to disease symptoms. In the retina, ELOVL4 is expressed exclusively in photoreceptors and produces VLC-PUFA that are incorporated into phosphatidylcholine and enriched in the light sensitive membrane disks of the photoreceptor outer segments. VLC-PUFA are enzymatically converted into "elovanoid" compounds that appear to provide paracrine signals that promote photoreceptor and neuronal survival. In the brain, the main ELOVL4 products are VLC-SFA that are incorporated into sphingolipids and enriched in synaptic vesicles, where they regulate kinetics of presynaptic neurotransmitter release. Understanding the function of ELOVL4 and its VLC-SFA and VLC-PUFA products will advance our understanding of basic mechanisms in neural signaling and has potential for developing novel therapies for seizure and neurodegenerative diseases.
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Affiliation(s)
- Ferenc Deák
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Oklahoma Center for Neurosciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Robert E Anderson
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Oklahoma Center for Neurosciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Jennifer L Fessler
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - David M Sherry
- Oklahoma Center for Neurosciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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20
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Endogenous production of n-3 long-chain PUFA from first feeding and the influence of dietary linoleic acid and the α-linolenic:linoleic ratio in Atlantic salmon ( Salmo salar). Br J Nutr 2019; 122:1091-1102. [PMID: 31409428 DOI: 10.1017/s0007114519001946] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Atlantic salmon (Salmo salar) possess enzymes required for the endogenous biosynthesis of n-3 long-chain PUFA (LC-PUFA), EPA and DHA, from α-linolenic acid (ALA). Linoleic acid (LA) competes with ALA for LC-PUFA biosynthesis enzymes leading to the production of n-6 LC-PUFA, including arachidonic acid (ARA). We aimed to quantify the endogenous production of EPA and DHA from ALA in salmon fed from first feeding on diets that contain no EPA and DHA and to determine the influence of dietary LA and ALA:LA ratio on LC-PUFA production. Salmon were fed from first feeding for 22 weeks with three diets formulated with linseed and sunflower oils to provide ALA:LA ratios of approximately 3:1, 1:1 and 1:3. Endogenous production of n-3 LC-PUFA was 5·9, 4·4 and 2·8 mg per g fish and that of n-6 LC-PUFA was 0·2, 0·5 and 1·4 mg per g fish in salmon fed diets with ALA:LA ratios of 3:1, 1:1 and 1:3, respectively. The ratio of n-3:n-6 LC-PUFA production decreased from 27·4 to 2·0, and DHA:EPA ratio increased and EPA:ARA and DHA:ARA ratios decreased, as dietary ALA:LA ratio decreased. In conclusion, with a dietary ALA:LA ratio of 1, salmon fry/parr produced about 28 μg n-3 LC-PUFA per g fish per d, with a DHA:EPA ratio of 3·4. Production of n-3 LC-PUFA exceeded that of n-6 LC-PUFA by almost 9-fold. Reducing the dietary ALA:LA ratio reduced n-3 LC-PUFA production and EPA:ARA and DHA:ARA ratios but increased n-6 LC-PUFA production and DHA:EPA ratio.
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21
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Garrido D, Kabeya N, Betancor MB, Pérez JA, Acosta NG, Tocher DR, Rodríguez C, Monroig Ó. Functional diversification of teleost Fads2 fatty acyl desaturases occurs independently of the trophic level. Sci Rep 2019; 9:11199. [PMID: 31371768 PMCID: PMC6671994 DOI: 10.1038/s41598-019-47709-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 07/10/2019] [Indexed: 01/27/2023] Open
Abstract
The long-chain (≥C20) polyunsaturated fatty acid biosynthesis capacity of fish varies among species, with trophic level hypothesised as a major factor. The biosynthesis capacity is largely dependent upon the presence of functionally diversified fatty acyl desaturase 2 (Fads2) enzymes, since many teleosts have lost the gene encoding a Δ5 desaturase (Fads1). The present study aimed to characterise Fads2 from four teleosts occupying different trophic levels, namely Sarpa salpa, Chelon labrosus, Pegusa lascaris and Atherina presbyter, which were selected based on available data on functions of Fads2 from closely related species. Therefore, we had insight into the variability of Fads2 within the same phylogenetic group. Our results showed that Fads2 from S. salpa and C. labrosus were both Δ6 desaturases with further Δ8 activity while P. lascaris and A. presbyter Fads2 showed Δ4 activity. Fads2 activities of herbivorous S. salpa are consistent with those reported for carnivorous Sparidae species. The results suggested that trophic level might not directly drive diversification of teleost Fads2 as initially hypothesised, and other factors such as the species' phylogeny appeared to be more influential. In agreement, Fads2 activities from P. lascaris and A. presbyter were similar to their corresponding phylogenetic counterparts Solea senegalensis and Chirostoma estor.
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Affiliation(s)
- Diego Garrido
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna, 38206, Santa Cruz de Tenerife, Spain
| | - Naoki Kabeya
- Department of Aquatic Bioscience, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Mónica B Betancor
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - José A Pérez
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna, 38206, Santa Cruz de Tenerife, Spain
| | - N Guadalupe Acosta
- Departamento de Biología Animal, Edafología y Geología, Universidad de La Laguna, La Laguna, 38206, Santa Cruz de Tenerife, Spain
| | - Douglas R Tocher
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - Covadonga Rodríguez
- 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, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
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22
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Han L, Ding J, Wang H, Zuo R, Quan Z, Fan Z, Liu Q, Chang Y. Molecular characterization and expression of SiFad1 in the sea urchin (Strongylocentrotus intermedius). Gene 2019; 705:133-141. [PMID: 31004713 DOI: 10.1016/j.gene.2019.04.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 12/29/2022]
Abstract
Fatty acid desaturases (Fads) are a key enzyme in the process of biosynthesis of highly unsaturated fatty acids (HUFAs). In this study, we cloned the full-length sequence of the SiFad1 gene (SiFad1) and analyzed its expression profiles during different developmental stages and in different tissues of Strongylocentrotus intermedius. The full-length cDNA of SiFad1 is composed of 1086 bp, with a putative open reading frame of 885 bp encoding a polypeptide of 294 amino acid (AA) residues. The predicted molecular mass of SiFad1 is 34.67 kDa and its theoretical pI is 8.41. The presence of conserved motifs including three histidine boxes (HXXXH, HXXHH, XXXHH), a FA_desaturases domain and three transmembrane domains suggests that SiFad1 belongs to the microsomal fatty acid desaturases family. Its tissue distribution showed that the highest expression of SiFad1 is in the intestine and the weakest expression is in Aristotle's lantern of S. intermedius. Time-course expression measurements in different developmental stages showed the highest expression of SiFad1 occurs in the gastrula and the weakest expression in the juvenile sea urchin. Knock-down of SiFad1 by specific siRNA revealed that the significantly depressed expression of Elovl5 had decreased in the coelomocytes, intestines and gonads at 24 h post transfection, indicating that the downstream target gene of SiFad1 is Elovl5 and SiFad1 and Elovl5 have positive regulatory effects. When we examined the changes in fatty acids in the gonads before and after interference, the results showed that after 24 h of interference, the content of C20:4n-6 produced by SiFad1 had decreased. Taken together, these results will enable us to understand the role of SiFad1 in fatty acid anabolism, which will help us to understand the fatty acid synthesis pathways and regulatory mechanisms of Strongylocentrotus intermedius and provide a theoretical experimental basis for improving the ability of sea urchins to synthesize fatty acids and cultivating sea urchins of higher quality and nutritional value.
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Affiliation(s)
- Lingshu Han
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Jun Ding
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China.
| | - Heng Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Rantao Zuo
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Zijiao Quan
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Zihan Fan
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Quandi Liu
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
| | - Yaqing Chang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning 116023, PR China
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23
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The long-chain monounsaturated cetoleic acid improves the efficiency of the n-3 fatty acid metabolic pathway in Atlantic salmon and human HepG2 cells. Br J Nutr 2019; 122:755-768. [PMID: 31288871 DOI: 10.1017/s0007114519001478] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The present study aimed to determine if the long-chain MUFA cetoleic acid (22 : 1n-11) can improve the capacity to synthesise the health-promoting n-3 fatty acids EPA and DHA in human and fish models. Human hepatocytes (HepG2) and salmon primary hepatocytes were first enriched with cetoleic acid, and thereafter their capacities to convert radio-labelled 18 : 3n-3 (α-linolenic acid, ALA) to EPA and DHA were measured. Increased endogenous levels of cetoleic acid led to increased production of radio-labelled EPA + DHA in HepG2 by 40 % and EPA in salmon hepatocytes by 12 %. In order to verify if dietary intake of a fish oil rich in cetoleic acid would have the same beneficial effects on the n-3 fatty acid metabolic pathway in vivo as found in vitro, Atlantic salmon were fed four diets supplemented with either sardine oil low in cetoleic acid or herring oil high in cetoleic acid at two inclusion levels (Low or High). The diets were balanced for EPA + DHA content within the Low and within the High groups. The salmon were fed these diets from 110 to 242 g. The level of EPA + DHA in liver and whole-body retention of docosapentaenoic acid and EPA + DHA relative to what was eaten, increased with increased dietary cetoleic acid levels. Thus, it is concluded that cetoleic acid stimulated the synthesis of EPA and DHA from ALA in human HepG2 and of EPA in salmon hepatocytes in vitro and increased whole-body retention of EPA + DHA in salmon by 15 % points after dietary intake of cetoleic acid.
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24
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CRISPR/Cas9-mediated ablation of elovl2 in Atlantic salmon (Salmo salar L.) inhibits elongation of polyunsaturated fatty acids and induces Srebp-1 and target genes. Sci Rep 2019; 9:7533. [PMID: 31101849 PMCID: PMC6525179 DOI: 10.1038/s41598-019-43862-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 05/02/2019] [Indexed: 01/01/2023] Open
Abstract
Atlantic salmon can synthesize polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (20:5n-3), arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3) via activities of very long chain fatty acyl elongases (Elovls) and fatty acyl desaturases (Fads), albeit to a limited degree. Understanding molecular mechanisms of PUFA biosynthesis and regulation is a pre-requisite for sustainable use of vegetable oils in aquafeeds as current sources of fish oils are unable to meet increasing demands for omega-3 PUFAs. By generating CRISPR-mediated elovl2 partial knockout (KO), we have shown that elovl2 is crucial for multi-tissue synthesis of 22:6n-3 in vivo and that endogenously synthesized PUFAs are important for transcriptional regulation of lipogenic genes in Atlantic salmon. The elovl2-KOs showed reduced levels of 22:6n-3 and accumulation of 20:5n-3 and docosapentaenoic acid (22:5n-3) in the liver, brain and white muscle, suggesting inhibition of elongation. Additionally, elovl2-KO salmon showed accumulation of 20:4n-6 in brain and white muscle. The impaired synthesis of 22:6n-3 induced hepatic expression of sterol regulatory element binding protein-1 (srebp-1), fatty acid synthase-b, Δ6fad-a, Δ5fad and elovl5. Our study demonstrates key roles of elovl2 at two penultimate steps of PUFA synthesis in vivo and suggests Srebp-1 as a main regulator of endogenous PUFA synthesis in Atlantic salmon.
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25
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Molecular cloning and functional characterization of elongase (elovl5) and fatty acyl desaturase (fads2) in sciaenid, Nibea diacanthus (Lacepède, 1802). Gene 2019; 695:1-11. [DOI: 10.1016/j.gene.2019.01.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 01/16/2019] [Accepted: 01/23/2019] [Indexed: 01/23/2023]
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26
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Katan T, Caballero-Solares A, Taylor RG, Rise ML, Parrish CC. Effect of plant-based diets with varying ratios of ω6 to ω3 fatty acids on growth performance, tissue composition, fatty acid biosynthesis and lipid-related gene expression in Atlantic salmon (Salmo salar). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 30:290-304. [PMID: 31003197 DOI: 10.1016/j.cbd.2019.03.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 01/02/2023]
Abstract
Little is known about how variation in omega-6 to omega-3 (ω6:ω3) fatty acid (FA) ratios affects lipid metabolism and eicosanoid synthesis in salmon, and the potential underlying molecular mechanisms. The current study examined the impact of five plant-based diets (12-week exposure) with varying ω6:ω3 (0.3-2.7) on the growth, tissue lipid composition (muscle and liver), and hepatic transcript expression of lipid metabolism and eicosanoid synthesis-related genes in Atlantic salmon. Growth performance and organ indices were not affected by dietary ω6:ω3. The liver and muscle FA composition was highly reflective of the diet (ω6:ω3 of 0.2-0.8 and 0.3-1.9, respectively) and suggested elongation and desaturation of the ω3 and ω6 precursors 18:3ω3 and 18:2ω6. Furthermore, proportions of ω6 and ω3 PUFA in both tissues showed significant positive correlations with dietary inclusion (% of diet) of soy and linseed oils, respectively. Compound-specific stable isotope analysis (CSIA) further demonstrated that liver long-chain polyunsaturated fatty acid (LC-PUFA) synthesis (specifically 20:5ω3 and 20:4ω6) was largely driven by dietary 18:3ω3 and 18:2ω6, even when 20:5ω3 and 22:6ω3 were supplied at levels above minimum requirements. In addition, significant positive and negative correlations were identified between the transcript expression of LC-PUFA synthesis-related genes and liver ω6 and ω3 LC-PUFA, respectively, further supporting FA biosynthesis. Liver ω3 LC-PUFA also correlated negatively with the eicosanoid synthesis-related transcripts pgds and cox1. This is the first study to use CSIA, hepatic transcriptome, and tissue lipid composition analyses concurrently to demonstrate the impact of plant-based diets with varying ω6:ω3 on farmed Atlantic salmon.
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Affiliation(s)
- Tomer Katan
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's A1C 5S7, NL. Canada.
| | - Albert Caballero-Solares
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's A1C 5S7, NL. Canada
| | | | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's A1C 5S7, NL. Canada
| | - Christopher C Parrish
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's A1C 5S7, NL. Canada.
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27
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Panserat S, Marandel L, Seiliez I, Skiba-Cassy S. New Insights on Intermediary Metabolism for a Better Understanding of Nutrition in Teleosts. Annu Rev Anim Biosci 2019; 7:195-220. [DOI: 10.1146/annurev-animal-020518-115250] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The rapid development of aquaculture production throughout the world over the past few decades has led to the emergence of new scientific challenges to improve fish nutrition. The diet formulations used for farmed fish have been largely modified in the past few years. However, bottlenecks still exist in being able to suppress totally marine resources (fish meal and fish oil) in diets without negatively affecting growth performance and flesh quality. A better understanding of fish metabolism and its regulation by nutrients is thus mandatory. In this review, we discuss four fields of research that are highly important for improving fish nutrition in the future: ( a) fish genome complexity and subsequent consequences for metabolism, ( b) microRNAs (miRNAs) as new actors in regulation of fish metabolism, ( c) the role of autophagy in regulation of fish metabolism, and ( d) the nutritional programming of metabolism linked to the early life of fish.
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Affiliation(s)
- S. Panserat
- INRA, University of Pau & Pays de l'Adour, E2S UPPA, UMR1419 Nutrition, Metabolisme, Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France
| | - L. Marandel
- INRA, University of Pau & Pays de l'Adour, E2S UPPA, UMR1419 Nutrition, Metabolisme, Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France
| | - I. Seiliez
- INRA, University of Pau & Pays de l'Adour, E2S UPPA, UMR1419 Nutrition, Metabolisme, Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France
| | - S. Skiba-Cassy
- INRA, University of Pau & Pays de l'Adour, E2S UPPA, UMR1419 Nutrition, Metabolisme, Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France
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28
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Lopes-Marques M, Kabeya N, Qian Y, Ruivo R, Santos MM, Venkatesh B, Tocher DR, Castro LFC, Monroig Ó. Retention of fatty acyl desaturase 1 (fads1) in Elopomorpha and Cyclostomata provides novel insights into the evolution of long-chain polyunsaturated fatty acid biosynthesis in vertebrates. BMC Evol Biol 2018; 18:157. [PMID: 30340454 PMCID: PMC6194568 DOI: 10.1186/s12862-018-1271-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 10/02/2018] [Indexed: 12/22/2022] Open
Abstract
Background Provision of long-chain polyunsaturated fatty acids (LC-PUFA) in vertebrates occurs through the diet or via endogenous production from C18 precursors through consecutive elongations and desaturations. It has been postulated that the abundance of LC-PUFA in the marine environment has remarkably modulated the gene complement and function of Fads in marine teleosts. In vertebrates two fatty acyl desaturases, namely Fads1 and Fads2, encode ∆5 and ∆6 desaturases, respectively. To fully clarify the evolutionary history of LC-PUFA biosynthesis in vertebrates, we investigated the gene repertoire and function of Fads from species placed at key evolutionary nodes. Results We demonstrate that functional Fads1Δ5 and Fads2∆6 arose from a tandem gene duplication in the ancestor of vertebrates, since they are present in the Arctic lamprey. Additionally, we show that a similar condition was retained in ray-finned fish such as the Senegal bichir and spotted gar, with the identification of fads1 genes in these lineages. Functional characterisation of the isolated desaturases reveals the first case of a Fads1 enzyme with ∆5 desaturase activity in the Teleostei lineage, the Elopomorpha. In contrast, in Osteoglossomorpha genomes, while no fads1 was identified, two separate fads2 duplicates with ∆6 and ∆5 desaturase activities respectively were uncovered. Conclusions We conclude that, while the essential genetic components involved LC-PUFA biosynthesis evolved in the vertebrate ancestor, the full completion of the LC-PUFA biosynthesis pathway arose uniquely in gnathostomes. Electronic supplementary material The online version of this article (10.1186/s12862-018-1271-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mónica Lopes-Marques
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U. Porto - University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.,Laboratory of Histology and Embryology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), U.Porto - University of Porto, Rua Jorge Viterbo Ferreira 228, P 4050-313, Porto, Portugal
| | - Naoki Kabeya
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yu Qian
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - Raquel Ruivo
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U. Porto - University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Miguel M Santos
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U. Porto - University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.,Faculty of Sciences (FCUP), Department of Biology, U.Porto - University of Porto, Rua do Campo Alegre, P 4169-007, Porto, Portugal
| | - Byrappa Venkatesh
- Comparative Genomics Laboratory, Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore, 138673, Singapore
| | - Douglas R Tocher
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - L Filipe C Castro
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), U. Porto - University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal. .,Faculty of Sciences (FCUP), Department of Biology, U.Porto - University of Porto, Rua do Campo Alegre, P 4169-007, Porto, Portugal.
| | - Óscar Monroig
- Institute of Aquaculture, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK. .,Instituto de Acuicultura Torre de la Sal (IATS-CSIC), Ribera de Cabanes, 12595, Castellón, Spain.
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29
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Zhu KC, Song L, Zhao CP, Guo HY, Zhang N, Guo L, Liu BS, Jiang SG, Zhang DC. The Transcriptional Factor PPARαb Positively Regulates Elovl5 Elongase in Golden Pompano Trachinotus ovatus (Linnaeus 1758). Front Physiol 2018; 9:1340. [PMID: 30319448 PMCID: PMC6167968 DOI: 10.3389/fphys.2018.01340] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/05/2018] [Indexed: 11/13/2022] Open
Abstract
The nuclear peroxisome proliferator-activated receptors (PPARs) regulate the transcription of elongases of very long-chain fatty acids (Elovl), which are involved in polyunsaturated fatty acid (PUFA) biosynthesis in mammals. In the present study, we first characterized the function of Elovl5 elongase in Trachinotus ovatus. The functional study showed that ToElovl5 displayed high elongation activity toward C18 and C20 PUFA. To investigate whether PPARαb was a regulator of Elovl5, we also reported the sequence of T. ovatus PPARαb (ToPPARαb). The open reading frame (ORF) sequence encoded 469 amino acids possessing four typical characteristic domains, including an N-terminal hypervariable region, a DNA-binding domain (DBD), a flexible hinge domain and a ligand-binding domain (LBD). Thirdly, promoter activity experiments showed that the region from PGL3-basic-Elovl5-5 (-146 bp to +459 bp) was defined as the core promoter by progressive deletion mutation of Elovl5. Moreover, PPARαb overexpression led to a clear time-dependent enhancement of ToElovl5 promoter expression in HEK 293T cells. Fourth, the agonist of PPARαb prominently increased PPARαb and Elovl5 expression, while PPARαb depletion by RNAi or an inhibitor was correlated with a significant reduction of Elovl5 transcription in T. ovatus caudal fin cells (TOCF). In conclusion, the present study provides the first evidence of the positive regulation of Elovl5 transcription by PPARαb and contributes to a better understanding of the transcriptional mechanism of PPARαb in fish.
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Affiliation(s)
- Ke-Cheng Zhu
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Ling Song
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Chao-Ping Zhao
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Hua-Yang Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Nan Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Liang Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Bao-Suo Liu
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Shi-Gui Jiang
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
| | - Dian-Chang Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation and Utilization, Ministry of Agriculture and Rural Affairs - South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.,Guangdong Provincial Engineer Technology Research Center of Marine Biological Seed Industry, Guangzhou, China.,Guangdong Provincial Key Laboratory of Fishery Ecology and Environment, Guangzhou, China
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30
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Lin Z, Huang Y, Zou W, Rong H, Hao M, Wen X. Cloning, tissue distribution, functional characterization and nutritional regulation of a fatty acyl Elovl5 elongase in chu's croaker Nibea coibor. Gene 2018; 659:11-21. [DOI: 10.1016/j.gene.2018.03.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/08/2018] [Accepted: 03/15/2018] [Indexed: 02/07/2023]
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31
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Dong Y, Zhao J, Chen J, Wang S, Liu Y, Zhang Q, You C, Monroig Ó, Tocher DR, Li Y. Cloning and characterization of ∆6/∆5 fatty acyl desaturase (Fad) gene promoter in the marine teleost Siganus canaliculatus. Gene 2018; 647:174-180. [DOI: 10.1016/j.gene.2018.01.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 01/04/2018] [Accepted: 01/08/2018] [Indexed: 01/18/2023]
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32
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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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Fadhlaoui M, Pierron F, Couture P. Temperature and metal exposure affect membrane fatty acid composition and transcription of desaturases and elongases in fathead minnow muscle and brain. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 148:632-643. [PMID: 29132009 DOI: 10.1016/j.ecoenv.2017.10.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/25/2017] [Accepted: 10/19/2017] [Indexed: 06/07/2023]
Abstract
In this study, we tested the hypothesis that metal exposure affected the normal thermal response of cell membrane FA composition and of elongase and desaturase gene transcription levels. To this end, muscle and brain membrane FA composition and FA desaturase (fads2, degs2 and scd2) and elongase (elovl2, elovl5 and elovl6) gene transcription levels were analyzed in fathead minnows (Pimephales promelas) acclimated for eight weeks to 15, 25 or 30°C exposed or not to cadmium (Cd, 6μg/l) or nickel (Ni, 450 6μg/l). The response of membrane FA composition to temperature variations or metal exposure differed between muscle and brain. In muscle, an increase of temperature induced a decrease of polyunsaturated FA (PUFA) and an increase of saturated FA (SFA) in agreement with the current paradigm. Although a similar response was observed in brain between 15 and 25°C, at 30°C, brain membrane unsaturation was higher than predicted. In both tissues, metal exposure affected the normal thermal response of membrane FA composition. The transcription of desaturases and elongases was higher in the brain and varied with acclimation temperature and metal exposure but these variations did not generally reflect changes in membrane FA composition. The mismatch between gene transcription and membrane composition highlights that several levels of control other than gene transcription are involved in adjusting membrane FA composition, including post-transcriptional regulation of elongases and desaturases and de novo phospholipid biosynthesis. Our study also reveals that metal exposure affects the mechanisms involved in adjusting cell membrane FA composition in ectotherms.
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Affiliation(s)
- Mariem Fadhlaoui
- Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490, rue de la Couronne, Québec QC Canada G1K 9A9
| | | | - Patrice Couture
- Institut National de la Recherche Scientifique, Centre Eau Terre Environnement, 490, rue de la Couronne, Québec QC Canada G1K 9A9.
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Cloning and functional characterization of fads2 desaturase and elovl5 elongase from Japanese flounder Paralichthys olivaceus. Comp Biochem Physiol B Biochem Mol Biol 2017; 214:36-46. [DOI: 10.1016/j.cbpb.2017.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/13/2017] [Accepted: 09/15/2017] [Indexed: 11/23/2022]
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Nannochloropsis oceania-derived defatted meal as an alternative to fishmeal in Atlantic salmon feeds. PLoS One 2017; 12:e0179907. [PMID: 28704386 PMCID: PMC5509142 DOI: 10.1371/journal.pone.0179907] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 06/06/2017] [Indexed: 01/06/2023] Open
Abstract
Defatted microalgal biomass derived from biorefinery can be potential feed ingredients for carnivorous fish. The present study investigated the growth, feed intake:gain and health parameters in Atlantic salmon fed for 84 days with defatted Nannochloropsis oceania as a fishmeal replacer. Fish fed feeds containing the algal biomass (at 10 and 20% inclusion, alga groups) were compared with groups that consumed alga-devoid feeds (control group). The fish that received 20% alga tended to have reduced weight gain and specific growth rate. Condition factor, feed conversion ratio and feed intake of this fish group were significantly different when compared with the control group. Hepatosomatic and viscerosomatic indices, whole body and fillet proximate composition were not affected by the dietary treatments. Digestibility of dry matter, protein, lipid, ash and energy, as well as retention of lipid and energy of the fish that received feed with 20% alga meal were also significantly different from those of the control group. Serum superoxide dismutase activity of the 10% alga-fed fish was significantly higher compared with the control fish. Although alga feeding did not cause any distal intestinal inflammation, the intestinal proteins that were altered upon feeding 20% algal meal might be pointing to systemic physiological disturbances. In conclusion, feeds with 20% alga had a negative effect on feed intake, FCR, lipid and energy retention and health of the fish. The defatted Nannochloropsis oceania can be used at modest inclusion levels, around 10%, without negative effects on the performance of Atlantic salmon.
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Roy S, Chakraborty HJ, Kumar V, Behera BK, Rana RS, Babu G. In Silico Structural Studies and Molecular Docking Analysis of Delta6-desaturase in HUFA Biosynthetic Pathway. Anim Biotechnol 2017; 29:161-173. [DOI: 10.1080/10495398.2017.1332639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | | | | | | | - R S Rana
- ICAR - Krishi Anusandhan Bhawan I, New Delhi, India
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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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Lin Z, Hao M, Zhu D, Li S, Wen X. Molecular cloning, mRNA expression and nutritional regulation of a Δ6 fatty acyl desaturase-like gene of mud crab, Scylla paramamosain. Comp Biochem Physiol B Biochem Mol Biol 2017; 208-209:29-37. [PMID: 28373120 DOI: 10.1016/j.cbpb.2017.03.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Revised: 03/18/2017] [Accepted: 03/28/2017] [Indexed: 11/17/2022]
Abstract
Fatty acyl desaturases (Fads) are critical enzymes in the pathways for the biosynthesis of the highly unsaturated fatty acids (HUFA). Here we report on the molecular cloning, tissue expression and nutritional regulation of a Δ6 fatty acyl desaturase-like (Δ6 Fad-like) gene from mud crab, Scylla paramamosain. The full-length cDNA was 1973bp, with a 201bp of 5'-UTR, a 443bp of 3'-UTR, and an ORF of 1329bp that encoded a protein of 442 amino acids. Bioinformatics analysis showed that the deduced peptide sequence possessed the typical features of the microsomal Fads, including N-terminal cytochrome b5 domain containing the heme-binding motif (H-P-G-G), three histidine-rich boxes and three membrane-spanning regions. Sequence comparison revealed that the predicted protein had a high percentage identity (>53%) with Δ6 Fads from other crustacean species. The tissue distribution of mud crab Δ6 Fad-like mRNA was found predominantly in hepatopancreas, with lower expression levels in all other tissues. Quantitative real-time PCR showed that the Δ6 Fad-like transcriptional levels in hepatopancreas gradually increased with the increased replacement of dietary fish oil (FO) by soybean oil (SO). The replacement ratio of FO by SO up to 60%, 80%, and 100% were significantly up-regulated by about 2.40-fold, 2.99-fold and 3.02-fold compared with that in the control group (100% FO) respectively (P<0.05). These results may contribute to better understanding the HUFA biosynthetic pathway and regulation mechanism in this species.
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Affiliation(s)
- Zhideng Lin
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China
| | - Meilin Hao
- College of Animal Science, South China Agricultural University, Guangzhou 510642, PR China
| | - Dashi Zhu
- College of Animal Science, Yangtze University, Jingzhou 434023, PR China
| | - Shengkang Li
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China
| | - Xiaobo Wen
- Guangdong Provincial Key Laboratory of Marine Biology, Shantou University, Shantou 515063, PR China.
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Bou M, Østbye TK, Berge GM, Ruyter B. EPA, DHA, and Lipoic Acid Differentially Modulate the n-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes. Lipids 2017; 52:265-283. [PMID: 28132119 DOI: 10.1007/s11745-017-4234-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 01/16/2017] [Indexed: 12/17/2022]
Abstract
The aim of the present study was to investigate how EPA, DHA, and lipoic acid (LA) influence the different metabolic steps in the n-3 fatty acid (FA) biosynthetic pathway in hepatocytes from Atlantic salmon fed four dietary levels (0, 0.5, 1.0 and 2.0%) of EPA, DHA or a 1:1 mixture of these FA. The hepatocytes were incubated with [1-14C] 18:3n-3 in the presence or absence of LA (0.2 mM). Increased endogenous levels of EPA and/or DHA and LA exposure both led to similar responses in cells with reduced desaturation and elongation of [1-14C] 18:3n-3 to 18:4n-3, 20:4n-3, and EPA, in agreement with reduced expression of the Δ6 desaturase gene involved in the first step of conversion. DHA production, on the other hand, was maintained even in groups with high endogenous levels of DHA, possibly due to a more complex regulation of this last step in the n-3 metabolic pathway. Inhibition of the Δ6 desaturase pathway led to increased direct elongation to 20:3n-3 by both DHA and LA. Possibly the route by 20:3n-3 and then Δ8 desaturation to 20:4n-3, bypassing the first Δ6 desaturase step, can partly explain the maintained or even increased levels of DHA production. LA increased DHA production in the phospholipid fraction of hepatocytes isolated from fish fed 0 and 0.5% EPA and/or DHA, indicating that LA has the potential to further increase the production of this health-beneficial FA in fish fed diets with low levels of EPA and/or DHA.
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Affiliation(s)
- Marta Bou
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, 1431, Ås, Norway. .,Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway.
| | - Tone-Kari Østbye
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, 1431, Ås, Norway
| | | | - Bente Ruyter
- Nofima (Norwegian Institute of Food, Fisheries and Aquaculture Research), P.O. Box 210, 1431, Ås, Norway.,Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway
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Molecular and functional characterization of a fads2 orthologue in the Amazonian teleost, Arapaima gigas. Comp Biochem Physiol B Biochem Mol Biol 2017; 203:84-91. [DOI: 10.1016/j.cbpb.2016.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/08/2016] [Accepted: 09/27/2016] [Indexed: 02/08/2023]
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Kjær MA, Ruyter B, Berge GM, Sun Y, Østbye TKK. Regulation of the Omega-3 Fatty Acid Biosynthetic Pathway in Atlantic Salmon Hepatocytes. PLoS One 2016; 11:e0168230. [PMID: 27973547 PMCID: PMC5156434 DOI: 10.1371/journal.pone.0168230] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 11/28/2016] [Indexed: 12/30/2022] Open
Abstract
Limited availability of the n-3 fatty acids EPA and DHA have led to an interest in better understanding of the n-3 biosynthetic pathway and its regulation. The biosynthesis of alpha-linolenic acid to EPA and DHA involves several complex reaction steps including desaturation-, elongation- and peroxisomal beta-oxidation enzymes. The aims of the present experiments were to gain more knowledge on how this biosynthesis is regulated over time by different doses and fatty acid combinations. Hepatocytes isolated from salmon were incubated with various levels and combinations of oleic acid, EPA and DHA. Oleic acid led to a higher expression of the Δ6 fatty acid desaturase (fad) genes Δ6fad_a, Δ6fad_b, Δ6fad_c and the elongase genes elovl2 compared with cells cultured in medium enriched with DHA. Further, the study showed rhythmic variations in expression over time. Levels were reached where a further increase in specific fatty acids given to the cells not stimulated the conversion further. The gene expression of Δ6fad_a_and Δ6fad_b responded similar to fatty acid treatment, suggesting a co-regulation of these genes, whereas Δ5fad and Δ6fad_c showed a different regulation pattern. EPA and DHA induced different gene expression patterns, especially of Δ6fad_a. Addition of radiolabelled alpha-linolenic acid to the hepatocytes confirmed a higher degree of elongation and desaturation in cells treated with oleic acid compared to cells treated with DHA. This study suggests a complex regulation of the conversion process of n-3 fatty acids. Several factors, such as that the various gene copies are differently regulated, the gene expression show rhythmic variations and gene expression only affected to a certain level, determines when you get the maximum conversion of the beneficial n-3 fatty acids.
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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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Kuah MK, Jaya-Ram A, Shu-Chien AC. A fatty acyl desaturase (fads2) with dual Δ6 and Δ5 activities from the freshwater carnivorous striped snakehead Channa striata. Comp Biochem Physiol A Mol Integr Physiol 2016; 201:146-155. [DOI: 10.1016/j.cbpa.2016.07.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/05/2016] [Accepted: 07/08/2016] [Indexed: 10/21/2022]
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Li W, Feng Z, Song X, Zhu W, Hu Y. Cloning, expression and functional characterization of the polyunsaturated fatty acid elongase (ELOVL5) gene from sea cucumber (Apostichopus japonicus). Gene 2016; 593:217-224. [PMID: 27538705 DOI: 10.1016/j.gene.2016.08.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 07/14/2016] [Accepted: 08/12/2016] [Indexed: 11/25/2022]
Abstract
Long chain polyunsaturated fatty acid (PUFA) are beneficial for maintaining the health, growth and development of an organism and could reduce the risk of some diseases. The ability to endogenously produce PUFA, especially in invertebrates, is largely unknown. To study the function of elongase genes in the PUFA biosynthesis of Apostichopus japonicus, we cloned an ELOVL5 homology gene from intestinal cDNA of A. japonicus (Aj-ELOVL5). The Aj-ELOVL5 gene encoded a 318 amino acid (AA) protein that exhibited all the characteristics of the ELOVL5 family, such as a histidine box motif and four putative transmembrane-spanning domains. The results of the tissue expression profile of Aj-ELOVL5 revealed that the body wall exhibited the highest expression level compared with other adult tissues. We also found that the Aj-ELOVL5 enzyme exhibited the ability to elongate γ-linolenic acid (18:3 n-6) and eicosapentaenoic acid (20:5 n-3) to dihomo-γ-linolenic acid (20:3 n-6) and docosapentaenoic acid (22:5 n-3), respectively. Our results indicated that the Aj-ELOVL5 enzyme had the capacity to biosynthesize PUFA from C18/C20 PUFA substrates.
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Affiliation(s)
- Wenxia Li
- Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Zhengfu Feng
- Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xiaojun Song
- Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Wei Zhu
- Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China.
| | - Yanjiang Hu
- Laboratory for Animal Nutrition and Immune Molecular Biology, College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
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Cloning and Characterization of Lxr and Srebp1, and Their Potential Roles in Regulation of LC-PUFA Biosynthesis in Rabbitfish Siganus canaliculatus. Lipids 2016; 51:1051-63. [DOI: 10.1007/s11745-016-4176-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 07/04/2016] [Indexed: 10/21/2022]
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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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Nutritional regulation of long-chain PUFA biosynthetic genes in rainbow trout (Oncorhynchus mykiss). Br J Nutr 2016; 115:1721-9. [DOI: 10.1017/s0007114516000830] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractMost studies on dietary vegetable oil in rainbow trout (Oncorhynchus mykiss) have been conducted on a background of dietary EPA (20 : 5n-3) and DHA (22 : 6n-3) contained in the fishmeal used as a protein source in aquaculture feed. If dietary EPA and DHA repress their endogenous synthesis from α-linolenic acid (ALA, 18 : 3n-3), then the potential of ALA-containing vegetable oils to maintain tissue EPA and DHA has been underestimated. We examined the effect of individual dietary n-3 PUFA on the expression of the biosynthetic genes required for metabolism of ALA to DHA in rainbow trout. A total of 720 juvenile rainbow trout were allocated to twenty-four experimental tanks and assigned one of eight diets. The effect of dietary ALA, EPA or DHA, in isolation or in combination, on hepatic expression of fatty acyl desaturase (FADS)2a(Δ6), FADS2b(Δ5), elongation of very long-chain fatty acid (ELOVL)5 and ELOVL2 was examined after 3 weeks of dietary intervention. The effect of these diets on liver and muscle phospholipid PUFA composition was also examined. The expression levels of FADS2a(Δ6), ELOVL5 and ELOVL2 were highest when diets were high in ALA, with no added EPA or DHA. Under these conditions ALA was readily converted to tissue DHA. Dietary DHA had the largest and most consistent effect in down-regulating the gene expression of all four genes. The ELOVL5 expression was the least responsive of the four genes to dietary n-3 PUFA changes. These findings should be considered when optimising aquaculture feeds containing vegetable oils and/or fish oil or fishmeal to achieve maximum DHA synthesis.
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Li S, Yuan Y, Wang T, Xu W, Li M, Mai K, Ai Q. Molecular Cloning, Functional Characterization and Nutritional Regulation of the Putative Elongase Elovl5 in the Orange-Spotted Grouper (Epinephelus coioides). PLoS One 2016; 11:e0150544. [PMID: 26950699 PMCID: PMC4780818 DOI: 10.1371/journal.pone.0150544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/15/2016] [Indexed: 01/17/2023] Open
Abstract
The enzymes involved in the biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFAs) are widely studied in fish species, as fish are the main source of n-3 LC-PUFAs for human beings. In the present study, a putative gene for elovl5, which encodes a key enzyme involved in LC-PUFA synthesis, was cloned and functionally characterized, and its transcription in response to dietary n-3 LC-PUFA exposure was investigated. Moreover, cell transfection and luciferase assays were used to explore the mechanism underlying the regulation of elovl5. The full-length cDNA of elovl5 was 1242 bp (excluding the polyA tail), including an 885 bp coding region encoding a 295 amino acid protein that possesses all of the characteristic features of elovl proteins. Functional characterization of heterologously expressed grouper Elovl5 indicated that it effectively elongates both C18 (18:2n-6, 18:3n-3, 18:3n-6 and 18:4n-3) and C20 (20:4n-6 and C20:5n-3) PUFAs, but not the C22 substrates. The expression of elovl5 was significantly affected by dietary n-3 LC-PUFA exposure: a high n-3 LC-PUFA level repressed the expression of elovl5 by slightly down-regulating the expression of sterol regulatory element-binding protein (SREBP)-1 and liver X receptor (LXR) α, which are major regulators of hepatic lipid metabolism. Promoter studies showed that grouper elovl5 reporter activity was induced by over-expression of LXRα but not SREBP-1. This finding suggests that elovl5 is a direct target of LXRα, which is involved in the biosynthesis of PUFAs via transcriptional regulation of elovl5. These findings may contribute to a further understanding of the mechanism underlying the regulation of LC-PUFA biosynthesis in marine fish species.
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Affiliation(s)
- Songlin Li
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Yuhui Yuan
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Tianjiao Wang
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Wei Xu
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Mingzhu Li
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Kangsen Mai
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Qinghui Ai
- Key Laboratory of Aquaculture Nutrition and Feed, Ministry of Agriculture, Ocean University of China, Qingdao 266003, People’s Republic of China
- Key Laboratory of Mariculture, Ministry Education of China, Ocean University of China, Qingdao 266003, People’s Republic of China
- Laboratory for Marine Fisheries and Aquaculture, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
- * E-mail:
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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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Watanabe K, Ohno M, Taguchi M, Kawamoto S, Ono K, Aki T. Identification of amino acid residues that determine the substrate specificity of mammalian membrane-bound front-end fatty acid desaturases. J Lipid Res 2015; 57:89-99. [PMID: 26590171 DOI: 10.1194/jlr.m064121] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Indexed: 11/20/2022] Open
Abstract
Membrane-bound desaturases are physiologically and industrially important enzymes that are involved in the production of diverse fatty acids such as polyunsaturated fatty acids and their derivatives. Here, we identified amino acid residues that determine the substrate specificity of rat Δ6 desaturase (D6d) acting on linoleoyl-CoA by comparing its amino acid sequence with that of Δ5 desaturase (D5d), which converts dihomo-γ-linolenoyl-CoA. The N-terminal cytochrome b5-like domain was excluded as a determinant by domain swapping analysis. Substitution of eight amino acid residues (Ser209, Asn211, Arg216, Ser235, Leu236, Trp244, Gln245, and Val344) of D6d with the corresponding residues of D5d by site-directed mutagenesis switched the substrate specificity from linoleoyl-CoA to dihomo-γ-linolenoyl-CoA. In addition, replacement of Leu323 of D6d with Phe323 on the basis of the amino acid sequence of zebra fish Δ5/6 bifunctional desaturase was found to render D6d bifunctional. Homology modeling of D6d using recent crystal structure data of human stearoyl-CoA (Δ9) desaturase revealed that Arg216, Trp244, Gln245, and Leu323 are located near the substrate-binding pocket. To our knowledge, this is the first report on the structural basis of the substrate specificity of a mammalian front-end fatty acid desaturase, which will aid in efficient production of value-added fatty acids.
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Affiliation(s)
- Kenshi Watanabe
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan
| | - Makoto Ohno
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan
| | - Masahiro Taguchi
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan
| | - Seiji Kawamoto
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan
| | - Kazuhisa Ono
- Department of Food Sciences and Biotechnology, Faculty of Life Sciences, Hiroshima Institute of Technology, Hiroshima, Japan
| | - Tsunehiro Aki
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima, Japan
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