Low C18 to C20 fatty acid elongase activity and limited conversion of stearidonic acid, 18:4(n–3), to eicosapentaenoic acid, 20:5(n–3), in a cell line from the turbot, Scophthalmus maximus

Ghioni, Cristina; Tocher, Douglas R.; Bell, Michael V.; Dick, James R.; Sargent, J. R.

doi:10.1016/s1388-1981(99)00010-4

Cited by 103 publications

(35 citation statements)

References 43 publications

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“…Correspondingly, fishes fed vegetable oil (50% or 100%) had high levels of C18:3n-3 and C18:2n-6 but low levels of n-3 LC-PUFAs in their muscles and liver, and this was especially pronounced in the large yellow croaker. Previous studies have demonstrated that marine fish species show less ability to synthesize LC-PUFAs from C18:3n-3 and C18:2n-68922383940. However, the mechanisms involved in the dietary regulation of LC-PUFA synthesis have rarely been studied in fish to date.…”

Section: Discussionmentioning

confidence: 99%

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Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish

Dong

Tan

Cai

et al. 2017

Sci Rep

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The present study was conducted to explore the mechanisms leading to differences among fishes in the ability to biosynthesize long-chain polyunsaturated fatty acids (LC-PUFAs). Replacement of fish oil with vegetable oil caused varied degrees of increase in 18-carbon fatty acid content and decrease in n-3 LC-PUFA content in the muscle and liver of rainbow trout (Oncorhynchus mykiss), Japanese seabass (Lateolabrax japonicus) and large yellow croaker (Larimichthys crocea), suggesting that these fishes have differing abilities to biosynthesize LC-PUFAs. Fish oil replacement also led to significantly up-regulated expression of FADS2 and SREBP-1 but different responses of the two PPAR-α homologues in the livers of these three fishes. An in vitro experiment indicated that the basic transcription activity of the FADS2 promoter was significantly higher in rainbow trout than in Japanese seabass or large yellow croaker, which was consistent with their LC-PUFA biosynthetic abilities. In addition, SREBP-1 and PPAR-α up-regulated FADS2 promoter activity. These regulatory effects varied considerably between SREBP-1 and PPAR-α, as well as among the three fishes. Taken together, the differences in regulatory activities of the two transcription factors targeting FADS2 may be responsible for the different LC-PUFA biosynthetic abilities in these three fishes that have adapted to different ambient salinity.

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Section: Discussionmentioning

confidence: 99%

“…In comparison with freshwater fish, marine fish species generally lack the ability to synthesize LC-PUFAs from their 18-carbon precursor fatty acids89. However, euryhaline fish commonly show varying levels of capacity to synthesize LC-PUFAs, depending on the ambient salinity101112.…”

mentioning

confidence: 99%

Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish

Dong

Tan

Cai

et al. 2017

Sci Rep

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“…Atlantic salmon have duplicated genes for both desaturases and elongases of fatty acids and, in the case of desaturases, duplicates appear to have diverged and neo- or subfunctionalised to provide enzymatic activities for the entire LC-PUFA pathway [26,27]. In contrast, other fish species, particularly marine carnivorous species, are incapable of endogenous production of significant amounts of LC-PUFA because they lack critical genes of the biosynthetic pathway [17,25,35]. It has been suggested that this enhancement of LC-PUFA capacity in salmonids has been a factor in their success in colonising relatively nutrient poor freshwater environments [27].…”

Section: Discussionmentioning

confidence: 99%

An evolutionary perspective on Elovl5 fatty acid elongase: comparison of Northern pike and duplicated paralogs from Atlantic salmon

et al. 2013

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BackgroundThe ability to produce physiologically critical LC-PUFA from dietary fatty acids differs greatly among teleost species, and is dependent on the possession and expression of fatty acyl desaturase and elongase genes. Atlantic salmon, as a result of a recently duplicated genome, have more of these enzymes than other fish. Recent phylogenetic studies show that Northern pike represents the closest extant relative of the preduplicated ancestral salmonid. Here we characterise a pike fatty acyl elongase, elovl5, and compare it to Atlantic salmon elovl5a and elovl5b duplicates.ResultsPhylogenetic analyses show that Atlantic salmon paralogs are evolving symmetrically, and they have been retained in the genome by purifying selection. Heterologous expression in yeast showed that Northern pike Elovl5 activity is indistinguishable from that of the salmon paralogs, efficiently elongating C18 and C20 substrates. However, in contrast to salmon, pike elovl5 was predominantly expressed in brain with negligible expression in liver and intestine.ConclusionsWe suggest that the predominant expression of Elovl5b in salmon liver and Elovl5a in salmon intestine is an adaptation, enabled by genome duplication, to a diet rich in terrestrial invertebrates which are relatively poor in LC-PUFA. Pike have retained an ancestral expression profile which supports the maintenance of PUFA in the brain but, due to a highly piscivorous LC-PUFA-rich diet, is not required in liver and intestine. Thus, the characterisation of elovl5 in Northern pike provides insights into the evolutionary divergence of duplicated genes, and the ecological adaptations of salmonids which have enabled colonisation of nutrient poor freshwaters.

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“…Certainly the discovery of a bifunctional enzyme in zebrafish is consistent with findings in the piscivorous marine species turbot (Scophthalmus maximus). In turbot, a deficiency in the fatty acid desaturation͞elongation pathway has been ascribed to a lack of C 18 -20 elongase function, while both ⌬6 and ⌬5 desaturase capabilities have been retained (40). However, in another marine species, gilthead sea bream (Sparus aurata), a block in the fatty acid desaturation͞elongation pathway has been identified as a deficiency in ⌬5 desaturase activity (41).…”

Section: Discussionmentioning

confidence: 99%

A vertebrate fatty acid desaturase with Δ5 and Δ6 activities

Hastings

Agaba

Tocher

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

307

275

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⌬5 and ⌬6 fatty acid desaturases are critical enzymes in the pathways for the biosynthesis of the polyunsaturated fatty acids arachidonic, eicosapentaenoic, and docosahexaenoic acids. They are encoded by distinct genes in mammals and Caenorhabditis elegans. This paper describes a cDNA isolated from zebrafish (Danio rerio) with high similarity to mammalian ⌬6 desaturase genes. The 1,590-bp sequence specifies a protein that, in common with other fatty acid desaturases, contains an N-terminal cytochrome b5 domain and three histidine boxes, believed to be involved in catalysis. When the zebrafish cDNA was expressed in Saccharomyces cerevisiae it conferred the ability to convert linoleic acid (18:2n-6) and ␣-linolenic acid (18:3n-3) to their corresponding ⌬6 desaturated products, 18:3n-6 and 18:4n-3. However, in addition it conferred on the yeast the ability to convert di-homo-␥-linoleic acid (20:3n-6) and eicosatetraenoic acid (20:4n-3) to arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-3), respectively, indicating that the zebrafish gene encodes an enzyme having both ⌬5 and ⌬6 desaturase activity. The zebrafish ⌬5͞⌬6 desaturase may represent a component of a prototypic vertebrate polyunsaturated fatty acids biosynthesis pathway.

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Low C18 to C20 fatty acid elongase activity and limited conversion of stearidonic acid, 18:4(n–3), to eicosapentaenoic acid, 20:5(n–3), in a cell line from the turbot, Scophthalmus maximus

Cited by 103 publications

References 43 publications

Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish

Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish

An evolutionary perspective on Elovl5 fatty acid elongase: comparison of Northern pike and duplicated paralogs from Atlantic salmon

A vertebrate fatty acid desaturase with Δ5 and Δ6 activities

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