High Levels of Icosapentaenoic Acid in the Lipids of Oyster Crassostrea gigas Ranging over Both Japan and France

International audienceThe lipid and fatty acids of the Pacific oyster, Crassostrea gigas, collected both in Japan and France, were analyzed. Triacylglycerols and sterols were the major classes in the neutral lipids of both populations of C. gigas between the two countries, and they had significant levels of phospholipids (phosphatidylethanolamine and phosphatidylcholine) with ceramideaminoethylphosphonate in their polar tissue lipids. The differences of 18:3n-3 and 22:6n-3 (docosahexaenoic acid; DHA) levels in the depot triacylglycerols suggest the influence of dietary phytoplankton in different environments of the two countries. Although the levels of the fatty acids slightly differed, that of 20:5n-3 (icosapentaenoic acid; EPA, 20.5-24.8%) in the triacylglycerols was specifically the highest fatty acid in all the samples. The major polyunsaturated fatty acids in the polar lipids of all samples were EPA (13.2-17.8% for phosphatidylethanolamine and 13.4-22.7% for phosphatidylcholine) and DHA (18.9-26.8% for phosphatidylethanolamine and 13.1-22.5% for phosphatidylcholine). The fluctuation of total PUFA levels in the polar lipids between samples of both countries suggests the influence of diet. In addition, the consistently high EPA levels in the phospholipids may compensate for the variation in DHA levels

Etude de la spécificité du cardiolipide et des plasmalogènes chez les mollusques bivalves (Apport des méthodes chromatographiques)

Le couplage des méthodes CLHP dites " sans acide " et " avec acide " a permis la séparation des sous-classes PEplasmalogène, PSplasmalogène et PCplasmalogène. Chez les 38 espèces de bivalve analysées, les acides gras NMI, le 20:1(n-11) ou le 22:4(n-9)trans13 sont préférentiellement incorporées dans les plasmalogènes et plus spécifiquement dans la PSplsm et la PEplsm. Cette association semble très caractéristique car ces acides gras sont les rares acides gras biosynthétisés par les bivalves marins. L'importance des aminophospholipides plasmalogènes (PS et PE) vis à vis de la PC indique une localisation préférentielle des plasmalogènes et donc des acides gras biosynthétisés sur la face interne des membranes cellulaires. La présence de l'un ou l'autre de ces acides gras pourrait être liée à l'évolution des bivalves. Concernant les cardiolipides des bivalves marins, la structure moléculaire de cette classe a été confirmée à partir d'analyses chromatographiques et structurales. (RMN et ESI+/MS). Les résultats de l'investigation effectuée sur 38 espèces ont démontré qu'il était possible de regrouper les cardiolipides en trois grands types caractéristiques. Un " type1 " correspondant à une composition contenant presque exclusivement du 22:6(n-3), un " type 2 " caractérisé par la présence conjointe du 22:6(n-3) et du 20 :5(n-3), le " type3 " correspondant à celle conjointe du 22 :6(n-3), du 18 :2(n-6) et du 18 :3(n-3). Ces différences apparaissent comme étant corrélés avec les grands taxons phylogénétiques établis chez les bivalves : les Filibranches Euptèriomorphes (CL de type 1), les Filibranches Ptériomorphes (CL de type 3) et les Eulamellibranches Hérédontes (CL de type 2)BREST-BU Droit-Sciences-Sports (290192103) / SudocPLOUZANE-Bibl.La Pérouse (290195209) / SudocSudocFranceF

La matière organique extractible et les lipides - Composition des effluents - Application au site de Morlaix

This report deals with the composition of lipidic organic matter in the raw and treated effluents from the urban treatment plant of Morlaix and its evolution during a daily cycle. The chemical characterization of the organic extract is given by its distribution in the lipidic classes and in individual compounds in the fatty acid and sterol fractions for some specific samples. The values of concentrations,fluxes and degree of removal in the plant for the soluble and particulate matter are discussed and compared with the corresponding data from the treatrnent plant of Toulon.La composition de la matière organique lipidique contenue dans les effluents brut et épuré de la station d'épuration de Morlaix a été déterminée au cours d'un cycle journalier. Elle est donnée par sa répartition en classes chimiques directement à partir de l'extrait organique brut et pour quelques échantillons en composés individuels dans les fractions acides gras et stérols après hydrolyse des constituants lipidiques. Les flux journaliers et les rendements d'épuration ont été calculés pour chaque classe lipidique et comparés aux valeurs obtenues sur le site de Toulon

cis-4,7,10,trans-13-22∶4 fatty acid distribution in phospholipids of pectinid species Aequipecten opercularis and Pecten maximus

International audienceThe distribution of cis-4,7,10,trans-13-docosate-traenoic (c4,7,10,t13-22∶4), a peculiar FA previously isolated in the glycerophospholipids of some pectinid bivalves, was investigated in glycerophospholipid classes and subclasses of separated organs (gills, mantle, gonads, and muscle) of the queen scallop Aequipecten opercularis and the king scallop Pecten maximus. Plasmalogen (Pls) and diacyl + alkyl (Ptd) forms of serine, ethanolamine, and choline glycerophospholipids were isolated by HPLC and their FA compositions analyzed by GC-FID. Pls and Ptd forms of serine glycerophospholipids (PlsSer and PtdSer), and to a lesser extend the Pls form of ethanolamine glycerophospholipids (PlsEtn), were found to be specifically enriched with c4,7,10,t13-22∶4. This specificity was found to decrease in the tested organs in the following order: gills, mantle, gonad, and muscle. In gills, c4,7,10,t13-22∶4 was shown to be the main unsaturated FA of serine glycerophospholipids in both Pls and Ptd forms (23.8 and 19.4 mol%, respectively, for A. opercularis, and 21.0 and 26.2 mol% for P. maximus). These results represent the first comprehensive report on the FA composition of plasmalogen serine subclass isolated from pectinid bivalves. The specific association of the PlsSer with the c4,7,10,t13-22∶4 for the two pectinid species can be paralleled to the specific association of the PlsSer with the non-methylene interrupted (NMI) FA and 20∶1(n−11) observed in mussels, clams, and oysters (Kraffe, E., Soudant, P., and Marty, Y. (2004) Fatty Acids of Serine, Ethanolamine and Choline Plasmalogens in Some Marine Bivalves, Lipids 39, 59-66.) This, led us to hypothesize a similar functional significance for c4,7,10,t13-22∶4, NMI FA, and 20∶1(n−11) associated with PlsSer subclass of bivalves

Membrane phospholipid composition of hemocytes in the Pacific oyster Crassostrea gigas and the Manila clam Ruditapes philippinarum

International audienceThe detailed sterol (free sterol proportions and compositions) and phospholipid (PL) compositions (relative proportions of PL classes and subclasses and their respective fatty acid (FA) compositions) of hemocyte membranes were investigated in two bivalve mollusks: the Pacific oyster Crassostrea gigas and the Manila clam Ruditapes philippinarum. Hemocyte membrane lipids of both species revealed similar general composition: i) their free sterol/PL ratio was above 0.4 and ii) their PL were predominated by the diacyl + alkyl forms of glycerophosphatidylcholine (PC), the plasmalogen form of glycerophosphatidylethanolamine (PE) and ceramide aminoethylphosphonate (CAEP). Free sterols were predominated by cholesterol in both species. Plasmalogen forms of PE and glycerophosphatidylserine (PS) represented 82-83% and 46-55% of total PE and PS, respectively. When compared to their respective diacyl + alkyl forms, plasmalogen forms of PE and PS were specifically enriched in non-methylene-interrupted (NMI) FA and 20:1n-11, suggesting a functional significance of these PL molecular species in bivalve hemocytes. Lysoglycerophosphatidylcholine (LysoPC) levels were found to be fairly high in hemocytes, accounting for about 8% of the PL Some species-specific features were also found. LysoPC and glycerophosphatidylinositol (PI) FA compositions differed between Ruditapes philippinarum and Crassostrea gigas. CAEP proportion was higher in R. philippinarum than in C. gigas (14.5% and 27.9% of the PL respectively). Hemolymph cell monolayer observations and flow-cytometric analyses revealed species-specific hemocyte morphology and sub-populations which could account for some of the observed species-specific membrane lipid compositions

Electrochemistry of cytochrome c immobilized on cardiolipin-modified electrodes: a probe for protein – lipid interactions

Electrochemistry of cytochrome c (cyt c) immobilized on a cardiolipin (CL) / phosphatidylcholine (PC) film supported on a glassy carbon electrode was investigated using variable-frequency AC voltammetry. At low ionic strength, we observed two redox-active subpopulations characterized by distinct values of potential (E1/2) and electron transfer rate constant (kET). At high ionic strength, only one subpopulation was detected, consistent with the existence of very stable cyt c – CL adducts, most probably formed by hydrophobic interactions between the protein and the fatty acid (FA) chains carried by CL. This subpopulation exhibits a comparatively high kET value (> 300 s−1) apparently changing with the structure of the FA chains of CL, i.e. 18:2(n-6) or 14:0. Our study suggests that electrochemistry can be a useful technique for probing protein − lipid interactions, and more particularly the role played by the specific structure of the FA chains of CL on cyt c binding

Occurrence of the cis-4,7,10, trans-13-22:4 Fatty Acid in the Family Pectinidae (Mollusca: Bivalvia)

International audienceThe present study aimed to elucidate the effective phylogenetic specificity of distribution of a cis-4,7,10, trans-13-22:4 (22:4(n-9)Δ13trans) among pectinids. For this purpose, we extended the analysis of membrane glycerophospholipids FA composition to 13 species of scallops, covering 11 genera and 7 tribes representatives of the three subfamilies Chlamydinae, Palliolinae and Pectininae and the subgroup Aequipecten. In species belonging to the subfamily Pectininae and the Aequipecten subgroup, 22:4(n-9)Δ13trans was found in substantial amounts, but it was absent in other species belonging to the subfamilies Chlamydinae and Palliolinae. Homologous non-methylene-interrupted (NMI) FA, also hypothesized to differ along phylogenetic lines in bivalves, were totally absent or present only in trace amounts in representatives of the Aequipecten subgroup but ranged from 0.3 to 4.5% of the total FA in Pectinidae, Chlamydinae, and Palliolinae subfamilies. The species-specific occurrence of NMI and 22:4(n-9)Δ13trans FA in membrane lipids of pectinids agrees with the most recent phylogenies based on shell morphology and molecular characteristics. We examined the potential timing of the appearance of 22:4(n-9)Δ13trans in pectinids on a geologic time scale

A striking parallel between cardiolipin fatty acid composition and phylogenetic belonging in marine bivalves: A possible adaptative evolution?

International audienceThirty-five species of marine mollusk bivalves were analyzed for their fatty acid (FA) composition of cardiolipin (Ptd(2)Gro). All species showed a Ptd(2)Gro with strong selectivity for only a few polyunsaturated fatty acids, but three characteristic FA profiles emerged, with clear parallels to bivalve phylogeny. A first group of 12 species belonging to the Eupteriomorphia subgroup (Filibranchia) was characterized by a Ptd(2)Gro almost exclusively composed of 22:6n-3, whereas in the four Filibranchia Pteriomorph species analyzed, this FA was combined with substantial proportions of 18:2n-6 and 18:3n-3. Finally, a third group of 20 species, all belonging to the Heterodonta subclass, possessed Ptd(2)Gro containing predominantly both 22:6n-3 and 20:5n-3. Polyunsaturated FA moieties and arrangements in the Ptd(2)Gro of some marine species investigated in other classes of the mollusk phylum (Gastropoda, Polyplacophora) were found to be different. The present results suggest that the specific Ptd(2)Gro FA compositions in bivalves are likely to be controlled and conserved in species of the same phylogenetic group. Functional significances of the evolution of this mitochondrial lipid structure in bivalves are discussed

Diet and performance in the scallop, Argopecten purpuratus : force production during escape responses and mitochondrial oxidative capacities

International audienceWe examined whether escape response performance and mitochondrial capacities could reveal differences created by feeding scallops, Argopecten purpuratus, mono-specific algal diets composed of either Chaetoceros calcitrans or Isochrysis galbana (variety T. iso) hereafter T. iso. Before and after feeding scallops with these diets, we assessed force production in vivo to evaluate escape response performance (initial and repeat). We measured oxidative capacities of mitochondria isolated from the adductor muscle and from the male and female portions of the gonad. Initial escape response performance was reduced more by the C. calcitrans diet than by the T. iso diet. Repeat escape responses, which require aerobic recuperation, were reduced by both treatments. The oxidative capacity of mitochondria isolated from muscle and female gonad was markedly lower in scallops fed C. calcitrans than in those fed T. iso. Flux through complex I–IV and through complex IV was also lower in mitochondria from muscle of scallops fed C. calcitrans than in those fed T. iso. Muscle aerobic capacity, assessed by citrate synthase activity, was lower in scallops fed C. calcitrans than in those fed T. iso. Despite the marked differences in fatty acid (FA) composition of the algal diets, the FA composition of mitochondrial phospholipids differed little between scallops fed C. calcitrans and those fed T. iso. Both escape response behaviour and mitochondrial capacities changed with feeding mono-specific diets. The simplicity of measurements of scallop escape responses suggests this as a practical means of evaluating the status of scallops for the two monoalgal diets tested

Altered membrane lipid composition and functional parameters of circulating cells in cockles (Cerastoderma edule) affected by disseminated neoplasia

International audienceMembrane lipid composition and morpho-functional parameters were investigated in circulating cells of the edible cockle (Cerastoderma edule) affected by disseminated neoplasia (neoplastic cells) and compared to those from healthy cockles (hemocytes). Membrane sterol levels, phospholipid (PL) class and subclass proportions and their respective fatty acid (FA) compositions were determined. Morpho-functional parameters were evaluated through total hemocyte count (THC), mortality rate, phagocytosis ability and reactive oxygen species (ROS) production. Both morpho-functional parameters and lipid composition were profoundly affected in neoplastic cells. These dedifferentiated cells displayed higher THC (5×), mortality rate (3×) and ROS production with addition of carbonyl cyanide m-chloro phenylhydrazone (1.7×) but lower phagocytosis ability (½×), than unaffected hemocytes. Total PL amounts were higher in neoplastic cells than in hemocytes (12.3 and 5.1 nmol × 10-6 cells, respectively). However, sterols and a particular subclass of PL (plasmalogens; 1-alkenyl-2-acyl PL) were present in similar amounts in both cell type membranes. This led to a two times lower proportion of these membrane lipid constituents in neoplastic cells when compared to hemocytes (20.5% vs. 42.1% of sterols in total membrane lipids and 21.7% vs. 44.2% of plasmalogens among total PL, respectively). Proportions of non-methylene interrupted FA- and 20:1n-11-plasmalogen molecular species were the most impacted in neoplastic cells when compared to hemocytes (⅓× and ¼×, respectively). These changes in response to this leukemia-like disease in bivalves highlight the specific imbalance of plasmalogens and sterols in neoplastic cells, in comparison to the greater stability of other membrane lipid components