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Ding H, Shi X, Wen Z, Zhu X, Chen P, Hu Y, Xiao K, Yang J, Tian T, Zhang D, Wang S, Li Y. Molecular Identification and Functional Characterization of LC-PUFA Biosynthesis Elongase ( elovl2) Gene in Chinese Sturgeon ( Acipenser sinensis). Animals (Basel) 2024; 14:2343. [PMID: 39199889 PMCID: PMC11350804 DOI: 10.3390/ani14162343] [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: 06/18/2024] [Revised: 07/16/2024] [Accepted: 08/01/2024] [Indexed: 09/01/2024] Open
Abstract
Elongases of very-long-chain fatty acids (Elovls) are critical rate-limiting enzymes that are involved in LC-PUFA biosynthesis through catalyzing the two-carbon elongation of a pre-existing fatty acyl chain. Thus far, several Elovls have been extensively studied in teleost. However, the functional and physiological roles of Elovls in chondrichthyans have rarely been reported. In this study, we identified and characterized elovl2 from the endangered Chinese sturgeon (Acipenser sinensis) by whole genome scanning. The results show that the coding sequence of elovl2 was 894 bp in length, for a putative protein of 297 amnio acids. Comparative genomic analyses indicated that Chinese sturgeon elovl2 was evolutionarily conserved. Functional characterization in yeast demonstrated that the Chinese sturgeon Elovl2 could efficiently elongate C20 (ARA and EPA) and C22 (22:4n-6 and 22:5n-3) substrates, confirming its critical roles in LC-PUFA biosynthesis. Spatial and temporal expression analyses showed high elovl2 mRNA levels were detected in the liver and brain and showed an increase trend both in embryonic and post-hatching stages. Interestingly, diets with vegetable oils as lipid sources could significantly induce the high expression of elovl2 in Chinese sturgeon, implying that the endogenous LC-PUFA biosynthesis pathway was stimulated by lack of LC-PUFA in their diets. Our findings will enhance our understanding about the evolutionary and functional roles of elovl2 and provide novel insights into the LC-PUFA biosynthesis mechanism in vertebrates.
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Affiliation(s)
- Haoze Ding
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou 515063, China
| | - Xuetao Shi
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Zhengyong Wen
- Key Laboratory of Sichuan Province for Fishes Conservation and Utilization in the Upper Reaches of the Yangtze River, Neijiang Normal University, Neijiang 641100, China;
| | - Xin Zhu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Pei Chen
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Yacheng Hu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Kan Xiao
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Jing Yang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Tian Tian
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Dezhi Zhang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
| | - Shuqi Wang
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Sciences, Shantou University, Shantou 515063, China
| | - Yang Li
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China; (H.D.); (X.S.); (X.Z.); (P.C.); (Y.H.); (K.X.); (J.Y.); (T.T.); (D.Z.)
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
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Yuan X, Liu R, Wei M, Li H, Sun J, Ji H. Fish oil replacement with different vegetable oils in Onychostoma macrolepis: Effects on fatty acid metabolism based on whole-body fatty acid balance method and genes expression. FISH PHYSIOLOGY AND BIOCHEMISTRY 2024; 50:1583-1603. [PMID: 38739220 DOI: 10.1007/s10695-024-01357-y] [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: 12/27/2023] [Accepted: 05/07/2024] [Indexed: 05/14/2024]
Abstract
To evaluate the fatty acid (FA) metabolism status and possibility as a DHA source of farmed Onychostoma macrolepis, a total of 168 fish (2.03 ± 0.23 g) were fed four diets supplemented with fish oil (FO), linseed oil (LO), soybean oil (SO), and a mixture of LO and SO oil (MO), respectively, for 70 days. Body FA compositions were modified reflecting dietary FAs. Comparing liver and intestine fatty acids with fish fed four diets, the content of ARA in fish fed SO was significantly higher than others (P < 0.05), but showed no difference in muscle. The tissue FA profile showed that the FO-fed group successfully deposited DHA, while the LO-fed group converted ALA to DHA effectively, as well as the liver and intestine EPA was notably highest in the FO group, whereas no difference between the FO and LO group in the muscle. The FA results showed that the DHA contents in the muscle of Onychostoma macrolepis are at a medium-high level compared with several other fish species with the highest aquaculture yield. Correspondingly, in the fish fed diet with LO, SO, and MO, the genes of most FA biosynthesis, transportation, and transcriptional regulation factors were increased in the liver and muscle, but no significant difference was observed in the gene expression of Elovl4b, FATP1, and FABP10 in the muscle. In addition, the enzyme activity involved in PUFA metabolism was higher in fish fed vegetable oil-based diets, corroborating the results of the gene expression. Increased in vivo elongase and desaturase (Δ5, Δ6, and Δ9) activities were recorded in fish fed fish oil-devoid diets, which resulted in the appearance of products associated with elongase and desaturase activities in fish. Besides, as the specific n-3 PUFA synthesis substrate, the dietary supplementation of ALA not only retains most of the nutrition value but also ensures the muscular texture, such as fiber diameter and density. It is concluded that farmed O. macrolepis owns strong n-3 LC-PUFA biosynthetic capacity and high DHA contents so it can be a good DHA source for the population.
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Affiliation(s)
- Xiangtong Yuan
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Ruofan Liu
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Mingkui Wei
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Handong Li
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Jian Sun
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China
| | - Hong Ji
- College of Animal Science and Technology, Northwest Agriculture and Forestry University, Yangling, 712100, Shaanxi, China.
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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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Evolution and Functional Characteristics of the Novel elovl8 That Play Pivotal Roles in Fatty Acid Biosynthesis. Genes (Basel) 2021; 12:genes12081287. [PMID: 34440461 PMCID: PMC8392482 DOI: 10.3390/genes12081287] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/20/2022] Open
Abstract
Elongation of very long-chain fatty acid (Elovl) proteins are key enzymes that catalyze the rate-limiting step in the fatty acid elongation pathway. The most recently discovered member of the Elovl family, Elovl8, has been proposed to be a fish-specific elongase with two gene paralogs described in teleosts. However, the biological functions of Elovl8 are still to be elucidated. In this study, we showed that in contrast to previous findings, elovl8 is not unique to teleosts, but displays a rather unique and ample phylogenetic distribution. For functional determination, we generated elovl8a (elovl8a−/−) and elovl8b (elovl8b−/−) zebrafish using CRISPR/Cas9 technology. Fatty acid composition in vivo and zebrafish liver cell experiments suggest that the substrate preference of Elovl8 overlapped with other existing Elovl enzymes. Zebrafish Elovl8a could elongate the polyunsaturated fatty acids (PUFAs) C18:2n-6 and C18:3n-3 to C20:2n-6 and C20:3n-3, respectively. Along with PUFA, zebrafish Elovl8b also showed the capacity to elongate C18:0 and C20:1. Gene expression quantification suggests that Elovl8a and Elovl8b may play a potentially important role in fatty acid biosynthesis. Overall, our results provide novel insights into the function of Elovl8a and Elovl8b, representing additional fatty acid elongases not previously described in chordates.
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De la Cruz-Alvarado FJ, Álvarez-González CA, Llera-Herrera R, Monroig Ó, Kabeya N, Rodríguez-Morales S, Concha-Frias B, Guerrero-Zárate R, Jiménez-Martínez LD, Peña-Marín ES. Expression of long-chain polyunsaturated fatty acids biosynthesis genes during the early life-cycle stages of the tropical gar Atractosteus tropicus. Comp Biochem Physiol B Biochem Mol Biol 2021; 256:110628. [PMID: 34052410 DOI: 10.1016/j.cbpb.2021.110628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 05/05/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022]
Abstract
Long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA), including eicosapentaenoic acid (EPA, 20:5n-3), arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), are essential in multiple physiological processes, especially during early development of vertebrates. LC-PUFA biosynthesis is achieved by two key families of enzymes, fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl). The present study determined the expression patterns of genes encoding desaturases (fads1 and fads2) and elongases (elovl2 and elovl5) involved in the LC-PUFA biosynthesis during early life-stages of the tropical gar Atractosteus tropicus. We further analyzed the fatty acid profiles during early development of A. tropicus to evaluate the impact of Fads and Elovl enzymatic activities. Specific oligonucleotides were designed from A. tropicus transcriptome to perform qPCR (quantitative polymerase chain reaction) on embryonic and larval stages, along with several organs (intestine, white muscle, brain, liver, heart, mesenteric adipose, kidney, gill, swim bladder, stomach, and spleen) collected from juvenile specimens. Fatty acid content of feeds and embryonic and larval stages were analyzed. Results show that fads1, fads2, elovl2 and elovl5 expression was detected from embryonic stages with expression peaks from day 15 post hatching, which could be related to transcriptional and dietary factors. Moreover, fads1, fads2 and elovl2 showed a higher expression in intestine, while elovl5 showed a higher expression in liver, suggesting that the tropical gar activates its LC-PUFA biosynthetic machinery to produce ARA, EPA and DHA to satisfy physiological demands at crucial developmental milestones during early development.
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Affiliation(s)
- Fanny Janet De la Cruz-Alvarado
- Laboratorio de Acuicultura Tropical, DACBIOL-UJAT, Carretera Villahermosa-Cárdenas KM 0.5, C.P.86139 Villahermosa, Tabasco, Mexico
| | - Carlos A Álvarez-González
- Laboratorio de Acuicultura Tropical, DACBIOL-UJAT, Carretera Villahermosa-Cárdenas KM 0.5, C.P.86139 Villahermosa, Tabasco, Mexico
| | - Raúl Llera-Herrera
- Instituto de Ciencias del Mar y Limnología - Unidad Académica Mazatlán, Universidad Nacional Autónoma de México, Joel Montes Camarena S/N, PO Box 811, Mazatlán, Sinaloa, Mexico
| | - Óscar Monroig
- Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain
| | - Naoki Kabeya
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Sergio Rodríguez-Morales
- Facultad de Química, Universidad Nacional Autónoma de México, Unidad de Química-Sisal, Puerto de Abrigo s/n, Sisal, Yucatán, Mexico
| | - Bartolo Concha-Frias
- División Académica Multidisciplinaria de Jalpa de Méndez, Universidad Juárez Autónoma de Tabasco, Carretera Nacajuca-Jalpa de Méndez R/a Rivera Alta, C.P. 86200 Jalpa de Méndez, Tabasco, Mexico
| | - Rocío Guerrero-Zárate
- Laboratorio de Acuicultura Tropical, DACBIOL-UJAT, Carretera Villahermosa-Cárdenas KM 0.5, C.P.86139 Villahermosa, Tabasco, Mexico
| | - Luis D Jiménez-Martínez
- División Académica Multidisciplinaria de Jalpa de Méndez, Universidad Juárez Autónoma de Tabasco, Carretera Nacajuca-Jalpa de Méndez R/a Rivera Alta, C.P. 86200 Jalpa de Méndez, Tabasco, Mexico.
| | - Emyr Saúl Peña-Marín
- Laboratorio de Acuicultura Tropical, DACBIOL-UJAT, Carretera Villahermosa-Cárdenas KM 0.5, C.P.86139 Villahermosa, Tabasco, Mexico; Consejo Nacional de Ciencia y Tecnología, CDMX, Mexico.
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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: 58] [Impact Index Per Article: 19.3] [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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Soo HJ, Sam KK, Chong J, Lau NS, Ting SY, Kuah MK, Kwang SY, Ranjani M, Shu-Chien AC. Functional characterisation of fatty acyl desaturase, Fads2, and elongase, Elovl5, in the Boddart's goggle-eyed goby Boleophthalmus boddarti (Gobiidae) suggests an incapacity for long-chain polyunsaturated fatty acid biosynthesis. JOURNAL OF FISH BIOLOGY 2020; 97:83-99. [PMID: 32222967 DOI: 10.1111/jfb.14328] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 03/15/2020] [Accepted: 03/17/2020] [Indexed: 06/10/2023]
Abstract
The biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA), a process to convert C18 polyunsaturated fatty acids into eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or arachidonic acid (ARA), requires the concerted activities of two enzymes, the fatty acyl desaturase (Fads) and elongase (Elovl). This study highlights the cloning, functional characterisation and tissue expression pattern of a Fads and an Elovl from the Boddart's goggle-eyed goby (Boleophthalmus boddarti), a mudskipper species widely distributed in the Indo-Pacific region. Phylogenetic analysis revealed that the cloned fads and elovl are clustered with other teleost orthologs, respectively. The investigation of the genome of several mudskipper species, namely Boleophthalmus pectinirostris, Periophthalmus schlosseri and Periophthalmus magnuspinnatus, revealed a single Fads2 and two elongases, Elovl5 and Elovl4 for each respective species. A heterologous yeast assay indicated that the B. boddarti Fads2 possessed low desaturation activity on C18 PUFA and no desaturation on C20 and C22 PUFA substrates. In comparison, the Elovl5 showed a wide range of substrate specificity, with a capacity to elongate C18, C20 and C22 PUFA substrates. An amino acid residue that affects the capacity to elongate C22:5n-3 was identified in the B. boddarti Elovl5. Both genes are highly expressed in brain tissue. Among all tissues, DHA is highly concentrated in neuron-rich tissues, whereas EPA is highly deposited in gills. Taken together, the results showed that due to the inability to perform desaturation steps, B. boddarti is unable to biosynthesise LC-PUFA, relying on dietary intake to acquire these nutrients.
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Affiliation(s)
- Han-Jie Soo
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Malaysia
| | - Ka Kei Sam
- Centre for Chemical Biology, Sains@USM, Bayan Lepas, Malaysia
| | - Joey Chong
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Malaysia
| | - Nyok-Sean Lau
- Centre for Chemical Biology, Sains@USM, Bayan Lepas, Malaysia
| | - Seng Yeat Ting
- Centre for Chemical Biology, Sains@USM, Bayan Lepas, Malaysia
| | - Meng-Kiat Kuah
- Centre for Chemical Biology, Sains@USM, Bayan Lepas, Malaysia
| | - Sim Yee Kwang
- Center for Marine and Coastal Studies, Universiti Sains Malaysia, Minden, Malaysia
| | | | - Alexander Chong Shu-Chien
- School of Biological Sciences, Universiti Sains Malaysia, Minden, Malaysia
- Centre for Chemical Biology, Sains@USM, Bayan Lepas, Malaysia
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