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Highly unsaturated fatty acid synthesis in vertebrates: new insights with the cloning and characterization of a delta6 desaturase of Atlantic salmon.
Lipids 2005; 40(1):13-24L

Abstract

Fish are an important source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids that are crucial to the health of higher vertebrates. The synthesis of HUFA involves enzyme-mediated desaturation, and a delta5 fatty acyl desaturase cDNA has been cloned from Atlantic salmon (Salmo salar) and functionally characterized previously. Here we report cloning and functional characterization of a delta6 fatty acyl desaturase of Atlantic salmon and describe its genomic structure, tissue expression, and nutritional regulation. A salmon genomic library was screened with a salmon delta5 desaturase cDNA and positive recombinant phage isolated and subcloned. The full-length cDNA for the putative fatty acyl desaturase was shown to comprise 2106 bp containing an open reading frame of 1365 bp specifying a protein of 454 amino acids (GenBank accession no. AY458652). The protein sequence included three histidine boxes, two transmembrane regions, and an N-terminal cytochrome b5 domain containing the heme-binding motif HPGG, all of which are characteristic of microsomal fatty acid desaturases. Functional expression showed that this gene possessed predominantly delta6 desaturase activity. Screening and sequence analysis of the genomic DNA of a single fish revealed that the delta6 desaturase gene constituted 13 exons in 7965 bp of genomic DNA. Quantitative real-time PCR assay of gene expression in Atlantic salmon showed that both delta6 and delta5 fatty acyl desaturase genes, and a fatty acyl elongase gene, were highly expressed in intestine, liver, and brain, and less so in kidney, heart, gill, adipose tissue, muscle, and spleen. Furthermore, expression of both delta6 and delta5 fatty acyl desaturase genes in intestine, liver, red muscle, and adipose tissue was higher in salmon fed a diet containing vegetable oil than in fish fed a diet containing fish oil.

Authors+Show Affiliations

Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, Scotland, United Kingdom.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15825826

Citation

Zheng, Xiaozhong, et al. "Highly Unsaturated Fatty Acid Synthesis in Vertebrates: New Insights With the Cloning and Characterization of a Delta6 Desaturase of Atlantic Salmon." Lipids, vol. 40, no. 1, 2005, pp. 13-24.
Zheng X, Tocher DR, Dickson CA, et al. Highly unsaturated fatty acid synthesis in vertebrates: new insights with the cloning and characterization of a delta6 desaturase of Atlantic salmon. Lipids. 2005;40(1):13-24.
Zheng, X., Tocher, D. R., Dickson, C. A., Bell, J. G., & Teale, A. J. (2005). Highly unsaturated fatty acid synthesis in vertebrates: new insights with the cloning and characterization of a delta6 desaturase of Atlantic salmon. Lipids, 40(1), pp. 13-24.
Zheng X, et al. Highly Unsaturated Fatty Acid Synthesis in Vertebrates: New Insights With the Cloning and Characterization of a Delta6 Desaturase of Atlantic Salmon. Lipids. 2005;40(1):13-24. PubMed PMID: 15825826.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Highly unsaturated fatty acid synthesis in vertebrates: new insights with the cloning and characterization of a delta6 desaturase of Atlantic salmon. AU - Zheng,Xiaozhong, AU - Tocher,Douglas R, AU - Dickson,Cathryn A, AU - Bell,J Gordon, AU - Teale,Alan J, PY - 2005/4/14/pubmed PY - 2005/8/20/medline PY - 2005/4/14/entrez SP - 13 EP - 24 JF - Lipids JO - Lipids VL - 40 IS - 1 N2 - Fish are an important source of the n-3 highly unsaturated fatty acids (HUFA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids that are crucial to the health of higher vertebrates. The synthesis of HUFA involves enzyme-mediated desaturation, and a delta5 fatty acyl desaturase cDNA has been cloned from Atlantic salmon (Salmo salar) and functionally characterized previously. Here we report cloning and functional characterization of a delta6 fatty acyl desaturase of Atlantic salmon and describe its genomic structure, tissue expression, and nutritional regulation. A salmon genomic library was screened with a salmon delta5 desaturase cDNA and positive recombinant phage isolated and subcloned. The full-length cDNA for the putative fatty acyl desaturase was shown to comprise 2106 bp containing an open reading frame of 1365 bp specifying a protein of 454 amino acids (GenBank accession no. AY458652). The protein sequence included three histidine boxes, two transmembrane regions, and an N-terminal cytochrome b5 domain containing the heme-binding motif HPGG, all of which are characteristic of microsomal fatty acid desaturases. Functional expression showed that this gene possessed predominantly delta6 desaturase activity. Screening and sequence analysis of the genomic DNA of a single fish revealed that the delta6 desaturase gene constituted 13 exons in 7965 bp of genomic DNA. Quantitative real-time PCR assay of gene expression in Atlantic salmon showed that both delta6 and delta5 fatty acyl desaturase genes, and a fatty acyl elongase gene, were highly expressed in intestine, liver, and brain, and less so in kidney, heart, gill, adipose tissue, muscle, and spleen. Furthermore, expression of both delta6 and delta5 fatty acyl desaturase genes in intestine, liver, red muscle, and adipose tissue was higher in salmon fed a diet containing vegetable oil than in fish fed a diet containing fish oil. SN - 0024-4201 UR - https://www.unboundmedicine.com/medline/citation/15825826/Highly_unsaturated_fatty_acid_synthesis_in_vertebrates:_new_insights_with_the_cloning_and_characterization_of_a_delta6_desaturase_of_Atlantic_salmon_ L2 - https://link.springer.com/article/10.1007/s11745-005-1355-7 DB - PRIME DP - Unbound Medicine ER -