A complete biosynthetic pathway of the long-chain polyunsaturated fatty acids in an amphidromous fish, ayu sweetfish Plecoglossus altivelis (Stomiati; Osmeriformes).

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 C or C PUFA substrates.

Examination of gammarid transcriptomes reveals a widespread occurrence of key metabolic genes from epibiont bdelloid rotifers in freshwater species.

Previous data revealed the unexpected presence of genes encoding for long-chain polyunsaturated fatty acid (LC-PUFA) biosynthetic enzymes in transcriptomes from freshwater gammarids but not in marine species, even though closely related species were compared. This study aimed to clarify the origin and occurrence of selected LC-PUFA biosynthesis gene markers across all published gammarid transcriptomes. Through systematic searches, we confirmed the widespread occurrence of sequences from seven elongases and desaturases involved in LC-PUFA biosynthesis, in transcriptomes from freshwater gammarids but not marine species, and clarified that such occurrence is independent from the gammarid species and geographical origin.

Determination of dietary essential fatty acids in a deep-sea fish, the splendid alfonsino Beryx splendens: functional characterization of enzymes involved in long-chain polyunsaturated fatty acid biosynthesis.

The splendid alfonsino Beryx splendens is a commercially important deep-sea fish in East Asian countries. Because the wild stock of this species has been declining, there is an urgent need to develop aquaculture systems. In the present study, we investigated the long-chain polyunsaturated fatty acid (LC-PUFA) requirements of B.

Impact of purine nucleotide on fatty acid metabolism and expression of lipid metabolism-related gene in the liver cell of rainbow trout Oncorhynchus mykiss.

Studies have suggested that dietary purine nucleotides (NT) affect the muscle and liver fatty acid composition of rainbow trout. To examine the direct regulation of liver fatty acid metabolism by purine NT in rainbow trout, the liver cells were cultured in the presence of 500 μmol/L inosine, adenosine, or guanosine monophosphate (IMP, AMP, or GMP). The expression of pparα was significantly decreased in the liver cells cultured with purine NT for 24 h, whereas the expression of fads2 (Δ5) was increased.

Functional characterization reveals a diverse array of metazoan fatty acid biosynthesis genes.

Long-chain (≥C ) polyunsaturated fatty acids (LC-PUFAs) are physiologically important fatty acids for most animals, including humans. Although most LC-PUFA production occurs in aquatic primary producers such as microalgae, recent research indicates the ability of certain groups of (mainly marine) invertebrates for endogenous LC-PUFA biosynthesis and/or bioconversion from dietary precursors. The genetic pathways for and mechanisms behind LC-PUFA biosynthesis remain unknown in many invertebrates to date, especially in non-model species.

The evolutionary ecology of fatty-acid variation: Implications for consumer adaptation and diversification.

The nutritional diversity of resources can affect the adaptive evolution of consumer metabolism and consumer diversification. The omega-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) have a high potential to affect consumer fitness, through their widespread effects on reproduction, growth and survival. However, few studies consider the evolution of fatty acid metabolism within an ecological context.

Expression of long-chain polyunsaturated fatty acids biosynthesis genes during the early life-cycle stages of the tropical gar Atractosteus tropicus.

Long-chain (≥C) 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.

Biosynthesis of Long-Chain Polyunsaturated Fatty Acids in Marine Gammarids: Molecular Cloning and Functional Characterisation of Three Fatty Acyl Elongases.

Long-chain (C) polyunsaturated fatty acids (LC-PUFAs) are essential nutrients that are mostly produced in marine ecosystems. Previous studies suggested that gammarids have some capacity to endogenously produce LC-PUFAs. This study aimed to investigate the repertoire and functions of elongation of very long-chain fatty acid (Elovl) proteins in gammarids.

A complete enzymatic capacity for biosynthesis of docosahexaenoic acid (DHA, 22 : 6n-3) exists in the marine Harpacticoida copepod .

The long-standing paradigm establishing that global production of Omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA) derived almost exclusively from marine single-cell organisms, was recently challenged by the discovery that multiple invertebrates possess methyl-end (or x) desaturases, critical enzymes enabling the biosynthesis of n-3 LC-PUFA. However, the question of whether animals with x desaturases have complete n-3 LC-PUFA biosynthetic pathways and hence can contribute to the production of these compounds in marine ecosystems remained unanswered. In the present study, we investigated the complete enzymatic complement involved in the n-3 LC-PUFA biosynthesis in , an intertidal harpacticoid copepod.

Flatfishes colonised freshwater environments by acquisition of various DHA biosynthetic pathways.

The colonisation of freshwater environments by marine fishes has historically been considered a result of adaptation to low osmolality. However, most marine fishes cannot synthesise the physiologically indispensable fatty acid, docosahexaenoic acid (DHA), due to incomplete DHA biosynthetic pathways, which must be adapted to survive in freshwater environments where DHA is poor relative to marine environments. By analysing DHA biosynthetic pathways of one marine and three freshwater-dependent species from the flatfish family Achiridae, we revealed that functions of fatty acid metabolising enzymes have uniquely and independently evolved by multi-functionalisation or neofunctionalisation in each freshwater species, such that every functional combination of the enzymes has converged to generate complete and functional DHA biosynthetic pathways.

Unique fatty acid desaturase capacities uncovered in illustrate the roles of aquatic invertebrates in trophic upgrading.

Omega-3 (3 or -3) long-chain polyunsaturated fatty acids (PUFA), including eicosapentaenoic acid and docosahexaenoic acid (DHA), play physiologically important roles in vertebrates. These compounds have long been believed to have originated almost exclusively from aquatic (mostly marine) single-cell organisms. Yet, a recent study has discovered that many invertebrates possess a type of enzymes called methyl-end desaturases () that enables them to endogenously produce -3 long-chain PUFA and could make a significant contribution to production of these compounds in the marine environment.

Functional diversification of teleost Fads2 fatty acyl desaturases occurs independently of the trophic level.

The long-chain (≥C) 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.

A key metabolic gene for recurrent freshwater colonization and radiation in fishes.

Colonization of new ecological niches has triggered large adaptive radiations. Although some lineages have made use of such opportunities, not all do so. The factors causing this variation among lineages are largely unknown.

Methyl-end desaturases with ∆12 and ω3 regioselectivities enable the de novo PUFA biosynthesis in the cephalopod Octopus vulgaris.

The interest in understanding the capacity of aquatic invertebrates to biosynthesise omega-3 (ω3) long-chain (≥C) polyunsaturated fatty acids (LC-PUFA) has increased in recent years. Using the common octopus Octopus vulgaris as a model species, we previously characterised a ∆5 desaturase and two elongases (i.e.

Functional characterisation of two Δ12-desaturases demonstrates targeted production of linoleic acid as pheromone precursor in .

Insect pheromones are often derived from fatty acid metabolism. Fatty acid desaturases, enzymes introducing double bonds into fatty acids, are crucial for the biosynthesis of these chemical signals. Δ12-desaturases catalyse the biosynthesis of linoleic acid by introducing a second double bond into oleic acid, but have been identified in only a few animal species.

The germ cell marker dead end reveals alternatively spliced transcripts with dissimilar expression.

Since the late 19th century, the Amazon species Colossoma macropomum (tambaqui) has been exploited commercially and the climate change has contributed to decline in tambaqui numbers. Although germ cell cryopreservation and transplantation can help preserve the species' genetic resources semipermanently, its germ cell behavior has not been analyzed to date. In this study, we isolated the tambaqui's dead end gene (dnd) homolog (tdnd) and used it as a molecular marker for germ cells to obtain basic information essential for transplantation.

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.

Background: Provision of long-chain polyunsaturated fatty acids (LC-PUFA) in vertebrates occurs through the diet or via endogenous production from C 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.

Isolation and characterization of a germ cell marker in teleost fish Colossoma macropomum.

The native Amazonian fish tambaqui (Colossoma macropomum) is the second-largest scaled fish in South America and the most common native species in Brazil. To preserve genetic resources with sufficient genetic diversity through germ cell cryopreservation and transplantation techniques, a molecular marker for identifying the cells is required to trace them during the manipulation processes. The vasa gene is a promising candidate, as its specific expression in germ cell lineage has been well-conserved throughout animal evolution.

"": A Draft Genome Assembly, Liver Transcriptome, and Nutrigenomics of the European Sardine, .

Clupeiformes, such as sardines and herrings, represent an important share of worldwide fisheries. Among those, the European sardine (, Walbaum 1792) exhibits significant commercial relevance. While the last decade showed a steady and sharp decline in capture levels, recent advances in culture husbandry represent promising research avenues.

A complete enzymatic capacity for long-chain polyunsaturated fatty acid biosynthesis is present in the Amazonian teleost tambaqui, Colossoma macropomum.

In vertebrates, the essential fatty acids (FA) that satisfy the dietary requirements for a given species depend upon its desaturation and elongation capabilities to convert the C polyunsaturated fatty acids (PUFA), namely linoleic acid (LA, 18:2n-6) and α-linolenic acid (ALA, 18:3n-3), into the biologically active long-chain (C) polyunsaturated fatty acids (LC-PUFA), including arachidonic acid (ARA, 20:4n-6), eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). Recent studies have established that tambaqui (Colossoma macropomum), an important aquaculture-produced species in Brazil, is a herbivorous fish that can fulfil its essential FA requirements with dietary provision C PUFA LA and ALA, although the molecular mechanisms underpinning such ability remained unclear. The present study aimed at cloning and functionally characterizing genes encoding key desaturase and elongase enzymes, namely fads2, elovl5 and elovl2, involved in the LC-PUFA biosynthetic pathways in tambaqui.

Genes for de novo biosynthesis of omega-3 polyunsaturated fatty acids are widespread in animals.

Marine ecosystems are responsible for virtually all production of omega-3 (ω3) long-chain polyunsaturated fatty acids (PUFA), which are essential nutrients for vertebrates. Current consensus is that marine microbes account for this production, given their possession of key enzymes including methyl-end (or "ωx") desaturases. ωx desaturases have also been described in a small number of invertebrate animals, but their precise distribution has not been systematically explored.

Cloning and functional characterization of fads2 desaturase and elovl5 elongase from Japanese flounder Paralichthys olivaceus.

Japanese flounder Paralichthys olivaceus has an essential requirement for long-chain polyunsaturated fatty acids (LC-PUFA), particularly docosahexaenoic acid and eicosapentaenoic acid, but the enzymes involved in LC-PUFA biosynthesis are thought to be absent or to have low activity. Teleost fish, in particular, have quite diversified substrate preference of these enzymes even among closely related species, implying that each species could have different LC-PUFA biosynthetic capabilities. Therefore, in the present study, we characterized Japanese flounder fatty acid desaturase 2 (Fads2) and elongation of very long-chain fatty acids protein 5 (Elovl5) in order to precisely characterize the LC-PUFA biosynthesis pathway.

Two alternative pathways for docosahexaenoic acid (DHA, 22:6n-3) biosynthesis are widespread among teleost fish.

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".

Biosynthesis of Polyunsaturated Fatty Acids in Sea Urchins: Molecular and Functional Characterisation of Three Fatty Acyl Desaturases from Paracentrotus lividus (Lamark 1816).

Sea urchins are broadly recognised as a delicacy and their quality as food for humans is highly influenced by their diet. Lipids in general and the long-chain polyunsaturated fatty acids (LC-PUFA) in particular, are essential nutrients that determine not only the nutritional value of sea urchins but also guarantee normal growth and reproduction in captivity. The contribution of endogenous production (biosynthesis) of LC-PUFA in sea urchins remained unknown.

Polyunsaturated fatty acid metabolism in a marine teleost, Nibe croaker Nibea mitsukurii: Functional characterization of Fads2 desaturase and Elovl5 and Elovl4 elongases.

To reduce the requirement for fish oil in marine aquaculture, it would be advantageous to endow marine fish species with the capability for the endogenous biosynthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). For this purpose, we have previously produced transgenic Nibe croaker (Nibea mitsukurii) carrying an elongase of very-long-chain fatty acids 2 (elovl2) gene isolated from Masu salmon (Oncorhynchus masou). However, fatty acid analysis revealed that 24:5n-3 accumulated in the liver of the transgenic fish, whereas the DHA level did not differ between non-transgenic and transgenic fish.