Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| aroma extracts from oyster crassostrea gigas: comparison of two extraction methods. | the study of the aroma of oysters is of great economic interest in france because it enables their organoleptic quality to be verified. the aim of this study is to optimize the extraction methods of the volatile compounds of oysters crassostrea gigas in order to obtain an extract with an odor as close as possible to that of the original oysters'. oyster aroma is rarely studied, and its sensory profile has not been investigated to date. two extraction methods were studied: vacuum hydrodistillatio ... | 2002 | 11782198 |
| [biological quality of seawater evaluated in situ with embryo-larval test of crassostrea gigas and mytilus galloprovincialis]. | embryos and larvae of bivalves are frequently used in marine ecotoxicology for the purpose of assessing seawater quality, because they are very sensitive to pollutants and provide rapid responses. laboratory studies, however, cannot accurately simulate natural conditions. we conducted bivalve embryo-larval studies in situ at the marina of arcachon (south-west french atlantic coast), in order to assess 'biological quality' of the water. one experiment conducted in winter 1999 (temperatures of 10 ... | 2001 | 11803816 |
| determination of an arsenosugar in oyster extracts by liquid chromatography-electrospray mass spectrometry and liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic fluorescence spectrometry. | hplc-uv-hg-afs analysis of aqueous extracts of oysters (crassostrea gigas) taken from the southwestern atlantic coast of spain showed the presence of arsenite, arsenate, dimethylarsinic acid and an unidentified arsenic peak. subsequent analysis of the oyster samples by lc-electrospray ms and comparison with four standard dimethylarsinoylribosides (arsenosugars), showed that the previously unidentified peak was an arsenosugar (arsenosugar 2). when the arsenosugar in the oyster was quantified usin ... | 2002 | 11827397 |
| genetic manipulations in aquaculture: a review of stock improvement by classical and modern technologies. | the aim of this review was to highlight the extent to which the genetic technologies are implemented by the aquaculture industry. the review shows that some of the modern genetic technologies are already extensively applied by the diverse aquaculture industries, though not to the same extent for all important aquacultured species (according to fao 1998 figures). some species (common carp, atlantic salmon, rainbow trout, channel catfish, nile tilapia, and the pacific oyster) received concentrated ... | 2001 | 11841164 |
| herpes-like virus detection in infected crassostrea gigas spat using dig-labelled probes. | an in situ hybridization protocol for detecting the herpes-like virus which infects french pacific oysters, crassostrea gigas, was developed. two dna probes were synthesized by incorporation of digoxigenin 11-dutp during pcr. two oyster herpes-like virus specific primer pairs, a5/a6 and c1/c6, were used. both dig-labelled probes were able to detect 50 pg of herpes-like virus pcr amplified dna in southern blot hybridizations. the probes hybridized with viral dna in paraffin sections of infected c ... | 2002 | 11849678 |
| p35-sensitive caspases, map kinases and rho modulate beta-adrenergic induction of apoptosis in mollusc immune cells. | apoptosis is an important mechanism for the preservation of a healthy and balanced immune system in vertebrates. little is known, however, about how apoptotic processes regulate invertebrate immune defenses. in the present study, we show that noradrenaline, a catecholamine produced by the neuroendocrine system and by immune cells in molluscs, is able to induce apoptosis of oyster crassostrea gigas hemocytes. the apoptosis-inducing effect of noradrenaline was mimicked by isoproterenol and blocked ... | 2002 | 11865032 |
| french scallops: a new host for ostreid herpesvirus-1. | sporadic high mortalities were reported among larval french scallops (pecten maximus). electron microscopy of moribund larvae revealed particles with the characteristics of a herpesvirus in association with cellular lesions. pcr and dna sequencing showed that the virus is a variant of ostreid herpesvirus-1 that has already been described in clams and oysters. this is the first description of a herpesvirus infection of a scallop species. the virus was transmitted successfully from an extract of i ... | 2001 | 11883198 |
| laboratory studies of cryopreservation of sperm and trochophore larvae of the eastern oyster. | the eastern oyster, crassostrea virginica, is the most important cultured oyster species of the atlantic and gulf coasts of the united states. cryopreservation of gametes and larvae of aquatic organisms has increased in importance in recent years. however, studies on the cryopreservation of sperm and larvae of mollusks have focused on the pacific oyster, crassostrea gigas. the present study was conducted to improve cryopreservation of sperm and trochophore larvae and to assess fertilizing abilit ... | 2001 | 11888215 |
| detection of oyster herpesvirus dna and proteins in asymptomatic crassostrea gigas adults. | since 1972, several herpes-like virus infections have been reported among different bivalve species around the world. most of these reports involved larvae or juveniles presenting high mortalities. two case reports of herpes-like viruses concerned adult oysters, crassostrea virginica in usa and ostrea angasi in australia. molecular techniques including pcr and in situ hybridization (ish) have been recently developed to detect the oyster herpesvirus genome. in the present study, 30 pacific oyster ... | 2002 | 11900847 |
| kinetics of metal elimination in oysters from a contaminated estuary. | in oysters crassostrea gigas translocated from a metal-enriched estuary (gironde, france) to a comparatively clean site, the bay of bourgneuf (france), cd, cu and zn concentrations were determined monthly in the whole soft tissues, or in different fractions (cytosolic or insoluble) of gills and digestive glands. in all cases, the concentrations of all of the three metals decreased logarithmically and half-lives were always shortest for cd (86-251 days). after 4 months, the cd concentration had b ... | 2002 | 11912053 |
| characteristics of trophic transfer of polychlorinated biphenyls in marine organisms in incheon north harbor, korea. | the trophic transfer of polychlorinated biphenyls (pcbs) was characterized for zooplankton (primarily paracalanus spp. and acartia spp.), pacific oyster (crassostrea gigas), shore crab (hemigrapsus penicillatus), and goby (acanthogobius hasta) in the aquatic system of incheon north harbor, korea. the congener pattern in the species was clearly divided by the main pcb uptake route. compared with zooplankton and oyster, the fraction of heavier homologues increased in crab and goby that take pcbs f ... | 2002 | 11951959 |
| immunochemical quantification of metallothioneins in marine mollusks: characterization of a metal exposure bioindicator. | a recombinant metallothionein cgmt1, from the pacific oyster crassostrea gigas, was synthesized and used as antigen in the development of antibodies and a specific enzyme-linked immunosorbent assay (elisa). the elisa showed that rabbit anti-cgmt1 igg reacted with purified cgmt1 and mts from other marine bivalves, indicating its suitability as a reagent to quantify mts and for monitoring of metal contamination in field animals. application of this assay to tissues excised from metal exposed c. gi ... | 2002 | 12013122 |
| [characterization of pathogenic bacteria of the cupped oyster crassostrea gigas]. | the french mollusc production is mainly based on the pacific cupped oyster, crassostrea gigas. since 1991, outbreaks of mass mortality of juveniles are reported during the summer period. these outbreaks are a major concern of oyster industry. several studies have established given bacterial strains to be pathogenic for bivalve species, including oysters. here we present a study of mortality outbreaks of c. gigas, as initiated in 1995. in a first step, bacterial strains were isolated during mass ... | 2002 | 12017771 |
| evidence of a tetradocosahexaenoic cardiolipin in some marine bivalves. | separation of phospholipid classes in lipid extracts from the scallop pecten maximus, the pacific oyster crassostrea gigas, and the blue mussel mytilus edulis was conducted using hplc. an isolated polar lipid fraction was found to contain a very high level of dha, up to 80 mol% of the total fa. ms with electrospray ionization in the positive-ion mode, tandem ms (ms-ms) and multidimensional nmr spectroscopy were used to analyze the detailed chemical structure of this polar lipid fraction. the iso ... | 2002 | 12056594 |
| cell culture of bivalves: tool for the study of the effects of environmental stressors. | spontaneous beating cells can be isolated from the heart of the oyster (crassostrea gigas) and cultured for more than two months. they form adherent contractile networks in culture conditions. they show muscarinic and beta-adrenergic reactivity thus showing that they are functional cardio-myocytes: acetylcholine induced a dose dependent decrease in spontaneous beating rate via an increase in potassium conductance, this effect being blocked by atropine. epinephrine induced a dramatic increase in ... | 2002 | 12064442 |
| use of metallothionein in gills from oysters (crassostrea gigas) as a biomarker: seasonal and intersite fluctuations. | the use of oyster gills for the analytical determination of metallothionein (mt) concentration as a biomarker of metal exposure was investigated. temporal variations in mt and metal concentrations (which can interfere with inter-site differences) were examined over a 7 month period (from spring to autumn) in japanese oysters from a clean site (bay of bourgneuf, france) and a metal-rich site (gironde estuary, france) as well as in individuals translocated from the clean to the contaminated area. ... | 2015 | 12101632 |
| comparative susceptibility of veliger larvae of four bivalve mollusks to a vibrio alginolyticus strain. | the susceptibility of 7 d old veliger larvae of the scallops argopecten ventricosus and nodipecten subnodosus, the penshell atrina maura, and the pacific oyster crassostrea gigas to a pathogenic strain of vibrio alginolyticus was investigated by challenging the larvae with different bacterial concentrations in a semi-static assay. the results indicate that the larvae of the 2 scallop species are more susceptible to the v. alginolyticus strain than those of the oyster and the penshell. signs of t ... | 2002 | 12113308 |
| influences of triploidy, parentage and genetic diversity on growth of the pacific oyster crassostrea gigas reared in contrasting natural environments. | an increasing number of hypotheses are being proposed to explain the faster growth potential of triploids in molluscs, including their partial sterility or their higher heterozygosity compared to diploids. triploid advantage however, remains controversial for poorer sites, because of a potential trade-off with survival. these questions were addressed in crassostrea gigas by deploying meiosis ii triploids and their diploid siblings from a single mass spawning of three males and seven females, in ... | 2002 | 12144669 |
| metabolic depression and whole-body response to enforced starvation by crassostrea gigas postlarvae. | physiological and biochemical measurements were performed on six oyster (crassostrea gigas) cohorts, in order to: (a) investigate the whole-body response (growth, energy content, metabolic and excretion rates) of 2-week-old postlarvae (spat) to enforced (0-8 days) starvation, and (b) test the potential use of three aerobic enzyme systems as indices of physiological condition. starvation resulted in exponential reduction of postlarval metabolic and excretion rates, as well as a linear decrease in ... | 2002 | 12160873 |
| relationships between contaminant levels in marine sediments and their biological effects on embryos of oysters, crassostrea gigas. | abstract-surface sediment samples from 10 coastal locations were analyzed with respect to their physical and chemical characteristics as well as their biological quality. the toxicity of the decanted fresh and freeze-dried sediments and of their elutriates was assessed by bioassays with embryos of the oysters crassostrea gigas. the concentration inhibiting normal embryogenesis in 20% of the larvae (ec20) was used as a measure of toxicity and compared with the physical and chemical properties of ... | 2002 | 12389908 |
| time should be considered in developmental ecotoxicity test. | developmental toxicity tests are often used for the hazard assessment of chemicals and environmental media. one of the most widely used is the oyster embryo larval test (oel), in which the development of oyster larvae is arrested at a single fixed time (e.g. 24 or 48 h) of toxic exposure, and the proportion of normal larvae measured. however, a major problem with this conventional approach is the lack of information on temporal trends in development. in this study, pacific oyster crassostrea gig ... | 2002 | 12398372 |
| protease inhibitors and haemagglutinins associated with resistance to the protozoan parasite, perkinsus marinus, in the pacific oyster, crassostrea gigas. | perkinsus marinus is a protozoan responsible for dramatic mortality in the eastern oyster, crassostrea virginica, but not in the pacific oyster, c. gigas. to understand the host-parasite relationship, we inoculated p. marinus trophozoites into the shell cavity of c. gigas and measured, over 2 months, (i) intensity of infection, (ii) protease inhibitory activities against p. marinus proteases and against bovine z-chymotrypsin, (iii) plasma haemagglutinin titre, (iv) plasma protein concentration, ... | 2002 | 12403320 |
| expression and activity of a multixenobiotic resistance system in the pacific oyster crassostrea gigas. | the multidrug resistance (mdr) mechanism corresponds to a defence system relying on the expression of high molecular membrane proteins that can actively lower the intracellular concentration of a wide variety of toxins, thus maintaining them below their toxic level. using rt-pcr, expression levels of a gene belonging to the class i of mammalian mdr genes, has been assessed in different developmental stages of the oyster crassostrea gigas. while no expression was found in the oocyte or the trocop ... | 2015 | 12408601 |
| genetic responses to metal contamination in two clams: ruditapes decussatus and ruditapes philippinarum. | coastal ecosystems are subjected to a wide variety of disturbances, including those due to xenobiotics of agricultural and industrial origin. these pollutants as heavy metals can modify the genetic diversity of populations by favouring or counter-selecting certain alleles or genotypes by differential mortality. in the present study, two genetic markers (phosphoglucomutase and glucosephosphate isomerase) and a protein marker (metallothionein) were monitored in order to determine the impact of hea ... | 2015 | 12408612 |
| xenobiotic-induced immunomodulation in the european flat oyster, ostrea edulis. | the presence of chemical contaminants in marine coastal waters is a major subject of concern since many molecules are potentially immunotoxic, even at low concentration. during the last decade, studies in sentinel species, such as the blue mussel, mytilus edulis, or the pacific oyster, crassostrea gigas, have revealed that immunosuppressive responses can be related to xenobiotic exposure, in the laboratory and in the field. in the present study, european flat oysters were experimentally exposed ... | 2006 | 12408622 |
| phototoxicity of pyrene and benzo[a]pyrene to embryo-larval stages of the pacific oyster crassostrea gigas. | there is a growing body of evidence to suggest that certain polycyclic aromatic hydrocarbons (pahs) pose a greater hazard to aquatic organisms than previously demonstrated, due to their potential to cause photo-induced toxicity when exposed to ultraviolet (uv) radiation. the consequences of photo-induced toxicity are reported here for embryo-larval stages of the pacific oyster crassostrea gigas, following exposure to pyrene and benzo[a]pyrene. during laboratory investigations, significant increa ... | 2013 | 12408628 |
| hsp70 expression in thermally stressed ostrea edulis, a commercially important oyster in europe. | synthesis of heat shock proteins (hsps) in response to elevated temperatures and other denaturing agents is a common feature of prokaryotic and eukaryotic cells. the heat-induced expression of hsp70 family members in the gills and mantle of ostrea edulis, a highly valued fisheries resource inhabiting primarily estuarine environments, has been studied. o edulis is exposed to a variety of natural and anthropogenic stresses in the environment. two isoforms of about 72 kda and 77 kda were constituti ... | 2002 | 12482201 |
| mollusc larval shell formation: amorphous calcium carbonate is a precursor phase for aragonite. | the larval shells of the marine bivalves mercenaria mercenaria and crassostrea gigas are investigated by polarized light microscopy, infrared spectroscopy, raman imaging spectroscopy, and scanning electron microscopy. both species contain similar shell ultrastructures. we show that larval shells contain amorphous calcium carbonate (acc), in addition to aragonite. the aragonite is much less crystalline than non-biogenic aragonite. we further show that the initially deposited mineral phase is pred ... | 2002 | 12486808 |
| gene structure and expression of cg-alr1, a type i activin-like receptor from the bivalve mollusc crassostrea gigas. | members of the transforming growth factor beta superfamily of cell signaling polypeptides have attracted much attention because of their ability, from nematodes to mammals, to control cellular functions that in turn, regulate embryo development and tissue homeostasis (the transforming growth factors betas 95 (1990) 419). to understand the divergent evolution of the structures and functions of the transforming growth factor beta receptors (superfamily) we report here the cloning and characterizat ... | 2002 | 12490320 |
| impact of atrazine on aneuploidy in pacific oysters, crassostrea gigas. | aneuploidy has previously been described and studied in the pacific oyster, crassostrea gigas, and has been shown to be negatively correlated with growth. the present study investigated the effect of atrazine on the level of aneuploidy in this species. crassostrea gigas adults and juveniles were subjected to different concentrations of atrazine representing a peak value found in a polluted environment (46.5 nm) and a value 10 times higher (465 nm). although atrazine did not show any effect on th ... | 2003 | 12503768 |
| effects of toxic dinoflagellates and toxin biotransformation in bivalves. | attempts were made to elucidate the different responses of shellfish to paralytic shellfish poison (psp) and the psp donor alexandrium minutum t1. five species of edible bivalves (crassostrea gigas, meretrix lusoria, mytilus edulis, ruditapes philippinarum, and soletellina diphos) were collected and examined for susceptibility to psp and psp donor. it was determined that all five bivalves had low susceptibility to psp following an intramuscular injection (> 300 mu/20 g). the abnormal effects on ... | 2002 | 12503874 |
| some methodological aspects of metallothionein evaluation. | the specificity of the methods used for metallothioneins (mts) determination in both field and laboratory studies is crucial to a relevant interpretation of the results. the technique applied in the present study is commonly used, but several potential problems may limit its validity: (i). the stability of the metal-sh links during heating and the possibility of metal exchanges between mts and others compounds; (ii). the presence of heat-stable thiol compounds with high molecular weight or very ... | 2003 | 12507607 |
| encapsulation of a lipid precursor, the eicosapentaenoic acid, to study the development of the crassostrea gigas oyster flavours. | the present study is part of a larger project whose aim is to understand how the oyster crassostrea gigas develops its aromas from a lipid precursor, the eicosapentaenoic acid (epa), in glyceride form. the objective of this study is, therefore, to prepare an encapsulation process that will enable the bivalve to be supplied with this lipid precursor. the complex coacervation method was chosen as it gave the best compatible microcapsules with respect to the nutritional aspects of oyster (i.e. dige ... | 2016 | 12519700 |
| the effects of elutriates from pah and heavy metal polluted sediments on crassostrea gigas (thunberg) embryogenesis, larval growth and bio-accumulation by the larvae of pollutants from sedimentary origin. | the release, bio-availability and toxicity of contaminants, when sediments are resuspended have been examined, studying concurrently their effects on the embryogenesis and on the larval growth of the crassostrea gigas larvae and their bio-accumulation in those organisms. three characteristic sediments have been selected (one contaminated by pahs, a second by heavy metals and the last by the both pollutants). the organisms were directly exposed to elutriates obtained from each sediment or fed on ... | 2002 | 12521137 |
| immune gene discovery by expressed sequence tags generated from hemocytes of the bacteria-challenged oyster, crassostrea gigas. | an expressed sequence tag program was undertaken to isolate genes involved in defense mechanisms of the pacific oyster, crassostrea gigas. putative function could be assigned to 54% of the 1142 sequenced cdnas. we built a public database where all est information are accessible through numerous search profiles (http://www.ifremer.fr/gigasbase). based on sequence similarities we identified 20 genes that may be implicated in immune function. we investigated the expression of four of these genes du ... | 2003 | 12559575 |
| molecular characterization of a cdna encoding putative vitellogenin from the pacific oyster crassostrea gigas. | to elucidate the molecular mechanisms involved in oogenesis, we applied a differential display method to identify genes whose expression was detected only in ovaries containing oocytes. one of the cdna fragments isolated by mrna differential display was similar in structure to vitellogenin. using this fragment, a full-length cdna encoding putative vitellogenin in the pacific oyster crassostrea gigas was cloned by race (rapid amplification of cdna ends), and its amino acid sequence was deduced. t ... | 2003 | 12560599 |
| study of atrazine effects on pacific oyster, crassostrea gigas, haemocytes. | shellfish farming is an important economic activity around the world. this activity often takes place in areas subjected to various recurring pollutions. the recrudescent use of herbicides in agriculture including atrazine implies pollutant transfer towards aquatic environment in estuarine areas. harmful effects of such substances on animals in marine environment, particularly on cultured bivalves, are poorly documented. bivalve molluscs such as mussels and oysters have been postulated as ideal ... | 2003 | 12570668 |
| polymorphism of metallothionein genes in the pacific oyster crassostrea gigas as a biomarker of response to metal exposure. | quantification of metallothioneins (mts) is classically associated with a cellular response to heavy metal contamination and is used in the monitoring of disturbed ecosystems. despite the characterization of several mt genes in marine bivalves, only a few genetic studies have used mt genes as potential biomarkers of pollution. the aim of this study was to assess whether mt gene polymorphism could be used to monitor exposure of the pacific oyster crassostrea gigas to heavy metals and to develop s ... | 2015 | 12581480 |
| hepatitis a virus detection in oysters (crassostrea gigas) in santa catarina state, brazil, by reverse transcription-polymerase chain reaction. | shellfish are readily contaminated with viruses present in water containing sewage because of the concentration effect of filter feeding. hepatitis a virus (hav) is the main cause of acute hepatitis worldwide and may lead to severe illness or even death. it is transmitted through fecal and oral routes and causes widespread endemic and asymptomatic infections in young children. here we describe a method for the detection of hav rna in shellfish involving the extraction of total rna from oyster me ... | 2003 | 12636311 |
| comparison of two microalgal diets. 1. influence on the biochemical and fatty acid compositions of raw oysters (crassostrea gigas). | oyster farming in france is a traditional activity. each year, 149 000 tons of oysters are fattened before being sold. more and more oyster farmers supplement the diet of oysters by microalgae to optimize the fattening process and to improve both the growth and flesh quality of oysters. in the present study, oysters were supplemented by two microalgae: skeletonema costatum and tahitian isochrysis clone. the ash, protein, carbohydrate (including glycogen), and lipid contents were analyzed. the gr ... | 2003 | 12643666 |
| comparison of two microalgal diets. 2. influence on odorant composition and organoleptic qualities of raw oysters (crassostrea gigas). | oyster farming is of real economic interest in france. oyster farmers attach more and more importance to improving the growth and the quality of their oysters. some fatty acids known to be aroma precursors originate from microalgae such as skeletonema costatum and tahitian isochrysis clone. these microalgae were used to fatten oysters in order to observe their role in the development of oysters' aroma. this study shows that the profile of fatty acids of oysters is influenced by the contribution ... | 2003 | 12643667 |
| apoptosis by rgd-containing peptides observed in hemocytes of the pacific oyster, crassostrea gigas. | we observed in vitro that after treatment with the arg-gly-asp (rgd) peptide, non-spreading crassostrea gigas hemocytes underwent cell death. utilizing a combination of a hoechst staining method and a dna fragmentation assay, the typical features of apoptosis were shown, i.e. cell shrinkage, membrane blebbing, chromatin condensation, and dna fragmentation. the hemocyte cell death caused by the rgd peptide appears to be sequence-specific, since no induction was shown in the alanine-substituted co ... | 2016 | 12697309 |
| assessment of the bioavailability and toxicity of sediment-associated polycyclic aromatic hydrocarbons and heavy metals applied to crassostrea gigas embryos and larvae. | sediments represent a vast sink for contaminants in aquatic systems, and may pose a threat to pelagic and benthic organisms. the objective of this research was to determine the bioavailability and toxicity of sediment-associated pahs and heavy metals, using embryos and larvae of the oyster crassostrea gigas, exposed to two sediment fractions: the whole sediment and the elutriate. the percentages of abnormal larvae, the contaminant accumulation and, (in the case of metal contamination), the induc ... | 2003 | 12705922 |
| metal concentrations in mussel crenomytilus grayanus and oyster crassostrea gigas in relation to contamination of ambient sediments. | the relationship between zn, cu, cd, pb, and ni concentrations in soft tissues of mussels and oysters and those in ambient sediments was examined. the study area was the coastal habitats of the northwestern sea of japan, which has a broad range of contamination due to urban sewage. significant increases of all metals, except ni, were observed in mussel crenomytilus grayanus at concentrations of easily leachable metals in ambient sediments higher than 2, 100, and 800 microg/g for cd, cu, and zn, ... | 2003 | 12705947 |
| isolation and 18s ribosomal dna gene sequences of marteilioides chungmuensis (paramyxea), an ovarian parasite of the pacific oyster crassostrea gigas. | to develop sensitive detection techniques with the aim of elucidating the life cycle of marteilioides chungmuensis, an intracellular paramyxean infecting the ovary of the pacific oyster crassostrea gigas, we isolated the parasite at the sporont stage from infected oysters using a freeze-thaw procedure at -20 degrees c and differential centrifugations in discontinuous sucrose and percoll gradients. dna was extracted from the isolated sporonts, and a pcr amplicon of 18s small subunit ribosomal rna ... | 2003 | 12747642 |
| natural water-purification system observed in a shallow coastal lagoon: matsukawa-ura, japan. | field surveys and in situ experiments were conducted in the shallow matsukawa-ura in summer to evaluate the biological efficiencies of shallow-water areas for preserving coastal ecosystems. in matsukawa-ura (5.8 km(2)), the suspension-feeding bivalves ruditapes philippinarum and crassostrea gigas were the dominant animals--their total biomasses (wet weight) were estimated to be 3.4 x 10(6) and 2.3 x 10(6) kg, respectively. ulva sp. and zostera marina were the dominant macrophyte species during t ... | 2003 | 12787612 |
| molecular detection of the oyster parasite mikrocytos mackini, and a preliminary phylogenetic analysis. | the protistan parasite mikrocytos mackini, the causative agent of denman island disease in the oyster crassostrea gigas in british columbia, canada, is of wide concern because it can infect other oyster species and because its life cycle, mode of transmission, and origins are unknown. pcr and fluorescent in situ hybridization (fish) assays were developed for m. mackini, the pcr assay was validated against standard histopathological diagnosis, and a preliminary phylogenetic analysis of the m. mac ... | 2003 | 12803386 |
| characterization of a tal/scl-like transcription factor in the pacific oyster crassostrea gigas. | we have cloned and characterized a cdna encoding cg-tal in the pacific oyster crassostrea gigas. the isolated cdna encodes a 219 amino acids protein that contains the basic helix-loop-helix (bhlh) domain homologous to that of vertebrate and invertebrate tal1/scl. phylogenetic analyses sustained that cg-tal belongs to this family of bhlh transcription factors. northern blot analysis of cg-tal mrna expression in adult oyster tissues indicated that cg-ta1 was specifically expressed in hemocytes, in ... | 2003 | 12818636 |
| molecular identification and expression of heat shock cognate 70 (hsc70) and heat shock protein 70 (hsp70) genes in the pacific oyster crassostrea gigas. | the 70-kda heat shock protein (hsp) family is composed of both environmentally inducible (hsp) and constitutively expressed (hsc) family members. we sequenced 2 genes encoding an hsp70 and an hsc70 in the pacific oyster crassostrea gigas. the cghsc70 gene contained introns, whereas the cghsp70 gene did not. moreover, the corresponding amino acid sequences of the 2 genes presented all the characteristic motifs of the hsp70 family. we also investigated the expression of hsp70 in tissues of oysters ... | 2003 | 12820657 |
| effect of a mono-specific algal diet on immune functions in two bivalve species--crassostrea gigas and ruditapes philippinarum. | the impact of diets upon the fatty acid composition of haemocyte polar lipids and consequently upon immune parameters has been tested in the oyster crassostrea gigas and the clam ruditapes philippinarum. oysters and clams were fed each of three cultured algae: chaetoceros calcitrans, which is rich in 20:5(n-3) and 20:4(n-6) and poor in 22:6(n-3) fatty acids; t-iso (isochrysis sp.), which is rich in 22:6(n-3) and deficient in 20:5(n-3) and 20:4(n-6); and tetraselmis suecica, which is deficient in ... | 2003 | 12878673 |
| effects of feeding oyster, crassostrea gigas, on serum and liver lipid levels in rats. | the effects of feeding dietary and defatted oyster meat on lipid metabolism were investigated in rats by comparing measurements with those of casein and soybean protein. in the first experiment, male rats were fed 0.1% and 1% cholesterol-supplemented diets containing casein, oyster or soybean protein under the same dietary level of protein (20%). the concentrations of serum and liver cholesterol in the oyster group were significantly lower than those in the casein group for both the 0.1% and 1% ... | 2003 | 12887155 |
| measurement of crassostrea gigas hemocyte oxidative metabolism by flow cytometry and the inhibiting capacity of pathogenic vibrios. | a flow cytometric method to measure the production of oxidative metabolism products was adapted for use with crassostrea gigas hemocytes. the method is based upon the oxidation, by hydrogen peroxide (h2o2), of intracellular 2',7'-dichlorofluorescin (dcfh) to green-fluorescent dichlorofluorescein. activation of the respiratory burst (rb) was tested using phorbol myristate acetate with no success. by contrast, activation by zymosan particles increased oxidation of dcfh in c. gigas hemocytes, mainl ... | 2003 | 12892744 |
| implication of brevetoxin b1 and pbtx-3 in neurotoxic shellfish poisoning in new zealand by isolation and quantitative determination with liquid chromatography-tandem mass spectrometry. | brevetoxin b1 (btx-b1) was isolated from austrovenus stutchburyi following the 1992-1993 outbreak of neurotoxic shellfish poisoning (nsp) in new zealand. we report here the first isolation of pbtx-3 from the same shellfish and the development of a procedure for quantitative determination of pbtx-3 and btx-b1. pbtx-3 was isolated by chromatography on columns of sio2, ods, and lh-20, followed by reverse-phase hplcs. in mass spectrometry (ms) with an electrospray ionization (esi) interface operatin ... | 2003 | 12893066 |
| geographical, temporal, and species variation of the polyether toxins, azaspiracids, in shellfish. | azaspiracid poisoning (azp) is a new toxic syndrome that has caused human intoxications throughout europe following the consumption of mussels (mytilus edulis), harvested in ireland. shellfish intoxication is a consequence of toxin-bearing microalgae in the shellfish food chain, and these studies demonstrated a wide geographic distribution of toxic mussels along the entire western coastal region of ireland. the first identification of azaspiracids in other bivalve mollusks including oysters (cra ... | 2003 | 12901653 |
| evaluation of damage in pacific oyster (crassostrea gigas) spermatozoa before and after cryopreservation using comet assay. | we examined the applicability of the comet assay (single cell gel electrophoresis assay) to estimate the quality of frozen-thawed pacific oyster (crassostrea gigas) spermatozoa. comet assay was performed on semen before and after cryopreservation followed by fluorescent staining with propidium iodide to assess dna integrity. after cryopreservation, the percentage of spermatozoa with damaged dna significantly increased, while only about half of the cells displayed intact dna, even when protected ... | 2013 | 12908027 |
| accumulation of organotin compounds in pacific oysters, crassostrea gigas, collected from aquaculture sites in taiwan. | butyltin and phenyltin residues were quantified in pacific oysters (crassostrea gigas), which were collected from several aquaculture sites along the west coast of taiwan during different seasons. butyltin compounds were detected in all of the samples, except in the oysters collected from the wanggung site in november 2002. monophenyltin and diphenyltin compounds were not detected in any of the samples. the average concentrations of monobutyltin, dibutyltin, tributyltin and tetrabutyltin in the ... | 2003 | 12922059 |
| mapk is involved in metaphase i arrest in oyster and mussel oocytes. | oocytes of crassostrea gigas and mytilus galloprovincialis are arrested in metaphase i when they are spawned and ready to be fertilized. to investigate the role of map kinase in maintaining metaphase i arrest, oocytes were exposed to the mek inhibitor u0126, and the effects on chromosome behavior and mapk activity were examined by bisbenzimide staining and in immunoblots with anti-phospho mapk antibodies. following treatment with 50 microm u0126, active mapk was undetectable and oocytes resumed ... | 2003 | 12941525 |
| sources of polychlorinated dibenzo-p-dioxins (pcdds), polychlorinated dibenzofurans (pcdfs), and coplanar polychlorinated biphenyls (co-pcbs), and their bioaccumulation through the marine food web in sendai bay, japan. | the concentrations of pcdd/f and co-pcb congeners in seawater, sediment, pacific oyster, japanese anchovy, marbled sole, and japanese flounder samples from sendai bay, japan, were analyzed. the compositions of total pcdd/f and total co-pcb concentrations in sediment and pacific oyster reflected that in seawater--the compositions of total pcdd, pcdf, and co-pcb concentrations were approximately 60, 10, and 30%, respectively. the compositions in japanese anchovy, marbled sole, and japanese flounde ... | 2003 | 12948237 |
| phenoloxidase activity in larval and juvenile homogenates and adult plasma and haemocytes of bivalve molluscs. | phenoloxidase (po) activity was studied in larval and juvenile homogenates and in the plasma and haemocytes of adult crassostrea gigas, argopecten ventricosus, nodipecten subnodosus, and atrina maura. samples were tested for the presence of po activity by incubation with the substrate l-3, 4-dihydroxyphenylalanine using trypsin, alpha-chymotrypsin, laminarin, lipopolysaccharides (lps), and sodium dodecyl sulphate (sds) to elicit activation of prophenoloxidase (propo) system. po activity was not ... | 2003 | 12969649 |
| insulin-like system and growth regulation in the pacific oyster crassostrea gigas: hrigf-1 effect on protein synthesis of mantle edge cells and expression of an homologous insulin receptor-related receptor. | the involvement of molecules belonging to the insulin/igf family in regulation of growth has been investigated in the pacific oyster crassostrea gigas. in vitro biological effects of human recombinant igf-1 (hrigf-1) on mantle edge cells, involved in oyster shell and soft body growth, were studied over an annual cycle. in mantle edge cells hrigf-1 stimulates protein synthesis of 56+/-5.1% over basal for 10(-10) m in september with in addition a clear dose-effect corresponding to the highest shel ... | 2003 | 13129502 |
| microbiology of shellfish. bacteriological study of the natural flora of pacific oysters (crassostrea gigas). | 1960 | 13811389 | |
| nucleotides of the pacific oyster crassostrea gigas (thunberg). | 1964 | 14217242 | |
| development of novel microsatellite dna markers from the pacific oyster crassostrea gigas. | we document the potential of novel microsatellites as a genetic tool in furthering our understanding of the crassostrea gigas genetic structure. from the microsatellite-enriched libraries we constructed, 123 repeat regions that had sufficient sequence information to design polymerase chain reaction primer sets were isolated. from these, 9 primer pairs were screened in a c. gigas population of 67 individuals to evaluate the genetic variability. all but 1 of the 9 loci showed allelic variation (nu ... | 2003 | 14502394 |
| molecular and physiological characterization of an invertebrate homologue of a calcitonin-related receptor. | calcitonin is a key hormone involved in the regulation of calcium metabolism in vertebrates. using oligonucleotide primers derived from consensus sequences of vertebrate calcitonin receptors, we have cloned and characterized the first representative of an invertebrate calcitonin receptor from the bivalve mollusc crassostrea gigas. this receptor named cg ct-r exhibits 39% amino acid sequence identity with both human calcitonin and calcitonin gene-related precursor receptors. cg ct-r is expressed ... | 2003 | 14550300 |
| aflp-based genetic linkage maps of the pacific oyster crassostrea gigas thunberg. | amplified fragment length polymorphisms (aflps) were used for genome mapping in the pacific oyster crassostrea gigas thunberg. seventeen selected primer combinations produced 1106 peaks, of which 384 (34.7%) were polymorphic in a backcross family. among the polymorphic markers, 349 were segregating through either the female or the male parent. chi -square analysis indicated that 255 (73.1%) of the markers segregated in a mendelian ratio, and 94 (26.9%) showed significant ( p < 0.05) segregation ... | 2006 | 14564534 |
| phenotypic plasticity of hsp70 and hsp70 gene expression in the pacific oyster (crassostrea gigas): implications for thermal limits and induction of thermal tolerance. | pacific oysters, crassostrea gigas, living at a range of tidal heights, routinely encounter large seasonal fluctuations in temperature. we demonstrate that the thermal limits of oysters are relatively plastic, and that these limits are correlated with changes in the expression of one family of heat-shock proteins (hsp70). oysters were cultured in the intertidal zone, at two tidal heights, and monitored for changes in expression of cognate (hsc) and inducible (hsp) heat-shock proteins during the ... | 2003 | 14583513 |
| quantification of gene transcription and enzyme activity for functionally important proteolytic enzymes during early development in the pacific oyster crassostrea gigas. | gene transcripts and enzyme activities were quantified for a selection of functionally important aminopeptidases at 2-day intervals throughout the first 72 days of development in the pacific oyster crassostrea gigas. leucine aminopeptidase (lap) and cathepsin b (cathb) gene transcripts were quantified using fluorogenic ('real time') pcr. lap and cathb gene transcripts were detected at all time points. the proportion of cathb transcripts remained essentially constant and low throughout developmen ... | 2003 | 14602147 |
| genetic polymorphism and trade-offs in the early life-history strategy of the pacific oyster, crassostrea gigas (thunberg, 1795): a quantitative genetic study. | we investigated genetic variability and genetic correlations in early life-history traits of crassostrea gigas. larval survival, larval development rate, size at settlement and metamorphosis success were found to be substantially heritable, whereas larval growth rate and juvenile traits were not. we identified a strong positive genetic correlation between larval development rate and size at settlement, and argue that selection could optimize both age and size at settlement. however, trade-offs, ... | 2003 | 14635840 |
| prevalence and infection intensity of the ovarian parasite marteilioides chungmuensis during an annual reproductive cycle of the oyster crassostrea gigas. | the occurrence of marteilioides chungmuensis, a protozoan paramyxean parasite in the reproductive system of the pacific oyster crassostrea gigas, was observed at gosung bay, korea. seasonal variation in gonad development was investigated in a suspended cultured oyster population. gametogenesis began in february and first-spawning was observed between mid and late june when surface water temperature reached 22 to 25 degrees c. spawning activity extended from mid june to late september, with 2 mar ... | 2003 | 14667038 |
| unique evolution of bivalvia arginine kinases. | the clams pseudocardium, solen, corbicula and ensis possess a unique form of arginine kinase (ak) with a molecular mass of 80 kda and an unusual two-domain structure, a result of gene duplication and subsequent fusion. these aks also lack two functionally important amino acid residues, asp(62) and arg(193), which are strictly conserved in other 40-kda aks and are assumed to be key residues for stabilizing the substrate-bound structure. however, these aks show higher enzyme activity. the cdna-der ... | 2004 | 14704858 |
| supplementation of perkinsus marinus cultures with host plasma or tissue homogenate enhances their infectivity. | the protozoan oyster parasite perkinsus marinus can be cultured in vitro in a variety of media; however, this has been associated with a rapid attenuation of infectivity. supplementation of defined media with products of p. marinus-susceptible (crassostrea virginica) and -tolerant (crassostrea gigas, crassostrea ariakensis) oysters alters proliferation and protease expression profiles and induces differentiation into morphological forms typically seen in vivo. it was not known if attenuation cou ... | 2004 | 14711671 |
| structure of amylase genes in populations of pacific cupped oyster ( crassostrea gigas): tissue expression and allelic polymorphism. | using the previously determined complementary dna sequence of crassostrea gigas amylase (y08370), we designed several oligonucleotide primers and used them with polymerase chain reaction (pcr) technology to characterize oyster amylase gene sequences. two genes encoding 2 different amylases were characterized and sequenced. the 2 genes are similarly organized with 8 exons and 7 introns. intron insertions are found at the same location in the 2 genes. sizes and nucleotide sequences are different f ... | 2003 | 14719164 |
| variation in the membrane transport properties and predicted optimal rates of freezing for spermatozoa of diploid and tetraploid pacific oyster, crassostrea gigas. | in the present study, a shape-independent differential scanning calorimeter (dsc) technique was used to measure the dehydration response during freezing of sperm cells from diploid and tetraploid pacific oysters, crassostrea gigas. this represents the first application of the dsc technique to sperm cells from nonmammalian species. volumetric shrinkage during freezing of oyster sperm cell suspensions was obtained at cooling rates of 5 and 20 degrees c/min in the presence of extracellular ice and ... | 2004 | 14736816 |
| microsatellite analysis of 6-hour-old embryos reveals no preferential intraspecific fertilization between cupped oysters crassostrea gigas and crassostrea angulata. | experimental examination of reproductive isolation is the first step in understanding hybridization processes. here, we studied preferential fertilization between 2 cupped oyster taxa, crassostrea angulata and crassostrea gigas, as a potential prezygotic reproductive isolation. early examination of sperm competition is now possible by molecular analysis of oyster embryos. this avoids the confounding effect of differential mortality during the larval stage. six hundred embryos were sampled from 2 ... | 2001 | 14961337 |
| a centromeric satellite sequence in the pacific oyster (crassostrea gigas thunberg) identified by fluorescence in situ hybridization. | a highly repetitive satellite sequence was previously identified in the pacific oyster crassostrea gigas thunberg. the sequence has 168 bp per unit, present in tandem repeats, and accounts for 1% to 4% of the genome. we studied the chromosomal location of this satellite sequence by fluorescence in situ hybridization (fish). a probe was made by polymerase chain reaction and incorporation of digoxigenin-11-dutp. hybridization was detected with fluorescein-labeled antidigoxigenin antibodies. fish s ... | 2001 | 14961342 |
| zinc in oysters (crassostrea gigas): chemical characteristics and action during in vitro digestion. | to obtain information on the luminal absorption of oyster zinc, the zinc action during an in vitro protease digestion of oysters was examined. more than 90% of the zinc rendered solute at ph 1.3 or 3.0 irrespective of the pepsin digestion. the solute zinc was partially re-precipitated by neutralization, and trypsin digestion did not render the re-precipitated zinc solute. when the pepsin digestion was performed at ph 5.0, the ratio of soluble zinc in trypsin digest decreased. when the trypsin di ... | 2003 | 14974730 |
| the oyster vasa-like gene: a specific marker of the germline in crassostrea gigas. | the vasa gene is a key determinant for germline formation in eukaryotes. this gene, highly conserved through evolution, encodes a rna helicase protein member of the dead-box family. to understand the germline formation in oyster, we report here the isolation and the characterization of a vasa orthologue in crassostrea gigas (oyvlg). oyvlg contained the eight consensus domains of the dead-box including those providing rna unwinding activity. the expression pattern of oyvlg was examined in adult o ... | 2004 | 14985097 |
| plasticity in resource allocation based life history traits in the pacific oyster, crassostrea gigas. i. spatial variation in food abundance. | we investigated the quantitative genetics of plasticity in resource allocation between survival, growth and reproductive effort in crassostrea gigas when food abundance varies spatially. resource allocation shifted from survival to growth and reproductive effort as food abundance increased. an optimality model suggests that this plastic shift may be adaptive. reproductive effort plasticity and mean survival were highly heritable, whereas for growth, both mean and plasticity had low heritability. ... | 2004 | 15009268 |
| cg-rel, the first rel/nf-kappab homolog characterized in a mollusk, the pacific oyster crassostrea gigas. | we report here the identification and functional characterization of cg-rel, a gene encoding the crassostrea gigas homolog of rel/nf-kappab transcription factors found in insects and mammals. sequence and phylogenetic analysis showed that cg-rel shares the structural organization of rel/nf-kappab transcription factors of class ii. it includes a rel homology domain as well as a c-terminal transactivation domain (td). overexpression of cg-rel in the drosophila s2 cell line activated the expression ... | 2004 | 15013754 |
| effects of storage method and duration on the toxicity of marine sediments to embryos of crassostrea gigas oysters. | the objective of laboratory sediment bioassays is to estimate in situ toxicity. this goal is difficult to achieve, as one of the main limitations of sediment toxicity tests is disruption of sediment geochemistry during sampling, handling and preservation. the effects of storage on the estimation of marine sediment toxicity to crassostrea gigas embryos and larvae were investigated. three storage methods and four storage periods were compared with three different sediment types contaminated by hea ... | 2004 | 15016466 |
| response of the pacific oyster crassostrea gigas to hydrocarbon contamination under experimental conditions. | hydrocarbon contamination perturbs the metabolism of the marine bivalve crassostrea gigas. to understand the response of this organism to hydrocarbon exposure, a suppression subtractive hybridisation method was employed to characterise up- and down-regulated genes during hydrocarbon exposure. the number of differentially expressed gene sequences obtained via this method was 258. the expression of genes involved in hydrocarbon detoxification (cytochrome p4501a1-like protein, cytochrome b(5), flav ... | 2004 | 15033537 |
| cadmium in oysters and scallops: the bc experience. | health effects of non-occupational lifetime exposure to cadmium (cd) are of growing concern worldwide. this overview provides some context for the current situation in coastal british columbia, canada, which arose in 1999 from the discovery of problematic residues of cd in farmed pacific oysters (crassostrea gigas). efforts are underway to define cd sources and the geographical and seasonal variation of these cd residues. the recent application by the european community of a 1 microg cd/g (wet w ... | 2004 | 15041066 |
| fatty acids of serine, ethanolamine, and choline plasmalogens in some marine bivalves. | the fa composition of glycerophospholipid (gpl) classes and subclasses was investigated in whole animals of three marine bivalve mollusks: the japanese oyster crassostrea gigas, the blue mussel mytilus edulis, and the manila clam ruditapes philippinarum. individual organs (gills, mantle, foot, siphon, and muscle) of the manila clam also were examined. the ps plasmalogen (psplsm), pe plasmalogen (peplsm), and pc plasmalogen (pcplsm) subclasses were isolated by hplc, and their individual fa compos ... | 2004 | 15055236 |
| transforming growth factor-beta-related proteins: an ancestral and widespread superfamily of cytokines in metazoans. | members of the transforming growth factor beta (tgf-beta) superfamily of cell signalling polypeptides have attracted much attention because of their ability, from nematodes to mammals, to control cellular functions that in turn, regulate embryo development and tissue homeostasis. on the basis of structure similarities, the tgf-beta members (ligands, receptors and smads) are subdivided into tgf-beta sensu stricto, bone morphogenetic proteins (bmp) and activins. although bmp is the best characteri ... | 2004 | 15062644 |
| relationship between copper speciation in sediments and bioaccumulation by marine bivalves of taiwan. | this paper evaluates the relationships between copper species in sediments and accumulation by the purple clam (hiatula diphos) and venus clam (gomphina aeguilatera) collected from the field and culture (aquaculture) ponds in the polluted coastal area of lukang, taiwan. sediment was sampled along with the molluscs, including oysters (crassostrea gigas), purple clams (hiatula diphos), rock-shells (thais clavigera), venus clams (gomphina aeguilatera), and hard clams (meretrix lusoria), from two un ... | 1996 | 15091451 |
| depuration of copper and zinc by green oysters and blue mussels of taiwan. | this paper describes depuration processes of copper and zinc in green oysters (crassostrea gigas) and in blue mussels (mytilus smarangdium) collected from an environment with heavy copper contamination, and then transferred to natural clean seawater. results show that the total loss of copper content per oyster is an exponential function of exposure time for the first 6 days with a depuration rate of 351 microg g(-1) day(-1) and then levels off. during this exponential decrease period approximat ... | 1993 | 15091803 |
| reduction of heavy metal content in hiroshima bay oysters (crassostrea gigas) by purification. | cultured oysters from hiroshima bay were analysed to determine the content of nine trace elements, cadmium (cd), lead (pb), chromium (cr), arsenic (as), manganese (mn), nickel (ni), copper (cu), zinc (zn), and iron (fe) and compared with oysters treated for 48 h in both artificial sea water and a solution of 0.5% ethylenediaminetetraacetic acid (edta) in artificial sea water. it was found that the values of as and fe in both groups of treated oysters were significantly lower than in the untreate ... | 1991 | 15092133 |
| green oysters caused by copper pollution on the taiwan coast. | the first case of green oysters (crassostrea gigas) broke out along the charting mariculture area of south-western taiwan in january 1986. the green color was found to be due to high copper content in the oyster tissue. since then, a long-term survey around this area shows that total dissolved copper ranges from 4.99 to 23.6 microg/liter and particulate copper ranges from 1.09 to 5.51 microg/liter in sea-water. the green oysters collected from the erhjin chi estuary on 26 january, 1989 gave the ... | 1990 | 15092258 |
| mussel watch: a review of cu and other metals in various marine organisms in taiwan, 1991-98. | this study presents the distribution of cu, zn, pb, cd, hg and as in various marine organisms collected along the western coast of taiwan from 1991 to 1998, and also evaluates the time variation of cu in oysters before (1980-85) and after (1986-98) the "green oyster" incident. the results show that relatively high geometric mean (gm) concentrations of cu, zn, pb, cd, as and hg were generally found in crassostrea gigas (cu=229 microg/g, zn=783 microg/g), gomphina aeguialtera (pb=30.3 microg/g), t ... | 2000 | 15092835 |
| depuration of metals from soft tissues of oysters (crassostrea gigas) transplanted from a contaminated site to clean sites. | the present study aimed at studying the transplantation of oysters from a polluted site lau fau shan (existing oyster culture zone) in deep bay to two clean sites mariculture zones at yung shue o and kat o. the hydrological data, growth of oyster shell length, mortality and metal contents in whole soft tissue were monitored from february 1993 to february 1994. the high growth phase (increase in shell length) and gametogenesis (decrease in dry weight of whole soft tissue) were noted in winter (wi ... | 1999 | 15093072 |
| phylogenetic study and identification of vibrio splendidus-related strains based on gyrb gene sequences. | different strains related to vibrio splendidus have been associated with infection of aquatic animals. an epidemiological study of v. splendidus strains associated with crassostrea gigas mortalities demonstrated genetic diversity within this group and suggested its polyphyletic nature. recently 4 species, v. lentus, v. chagasii, v. pomeroyi and v. kanaloae, phenotypically related to v. splendidus, have been described, although biochemical methods do not clearly discriminate species within this g ... | 2004 | 15109135 |
| pathogenicity testing of shellfish hatchery bacterial isolates on pacific oyster crassostrea gigas larvae. | bacterial diseases are a major cause of larval mortality in shellfish hatcheries. even with proper sanitation measures, bacterial pathogens cannot be eliminated in all cases. the pathogenicity of bacteria isolated from pacific northwest shellfish hatcheries to pacific oyster crassostrea gigas larvae was investigated. we found 3 highly pathogenic strains and 1 mildly pathogenic strain among 33 isolates tested. these strains appear to be members of the genus vibrio. although there have been many s ... | 2004 | 15109146 |
| in vitro effects of cadmium and mercury on pacific oyster, crassostrea gigas (thunberg), haemocytes. | in the past decades, shellfish culture has developed in a significant way around the world. however, culture areas are often subject to recurring anthropic pollution. the recrudescent presence of industrial wastes is a source of heavy metals and results in pollutant transfer towards the aquatic environment in estuarine areas. because of their mode of life, bivalves, including mussels and oysters, are suggested as ideal indicator organisms. the development of techniques allowing the analysis of t ... | 2004 | 15123292 |
| ontogenetic variations of hydrolytic enzymes in the pacific oyster crassostrea gigas. | occurrence and level of hydrolytic enzymatic activity (proteases, glycosidases, phosphatases, lipases, and esterases) were studied in oocytes, larvae, juveniles, and adult haemolymph of the pacific oyster crassostrea gigas. samples were obtained as oocyte lysate supernatant, larval homogenate supernatant, juvenile homogenate supernatant, haemocyte lysate supernatant, and plasma. the presence of enzymes was demonstrated by colorimetric and lysoplate assay techniques. between stages, significant d ... | 2004 | 15123298 |
| induction of haploid androgenesis in pacific oyster by uv irradiation. | androgenesis, development from paternal but not maternal chromosomes, can be induced in some organisms including fish, but has not been induced previously in mollusk. in this study we investigated the induction of haploid androgenesis in the pacific oyster by ultraviolet irradiation and observed nuclear behavior in the androgenetic eggs. irradiation for 90 seconds at a uv intensity of 72 erg/mm2 per second (6480 erg/mm2) was the optimal dose to achieve haploid androgenesis. the fertilization and ... | 2006 | 15136919 |
| insights into the anti-microbial defense of marine invertebrates: the penaeid shrimps and the oyster crassostrea gigas. | research on innate immunity of the penaeid shrimps and the oyster crassostrea gigas is motivated greatly by economical necessities. indeed, the aquaculture of these organisms is now limited by the development of infectious diseases. studying anti-microbial peptides/proteins (amps), which are effector molecules of the host defense, is particularly attractive not only for progressing basic knowledge on immunity but also because they offer various possible applications for disease management in aqu ... | 2004 | 15199961 |
| screening of vibrio isolates to develop an experimental infection model in the pacific oyster crassostrea gigas. | in an attempt to develop a reproducible experimental model of bacterial infection in crassostrea gigas, oysters taken from very localised sub-populations suffering natural mortality outbreaks were used in cohabitation trials under laboratory conditions. from these trials, a collection of vibrio strains was isolated from moribund and healthy oysters. in a second step, strains were experimentally tested for virulence by means of injection into healthy oysters. this screening revealed a span of vir ... | 2004 | 15212292 |
| oyster vasa-like gene as a marker of the germline cell development in crassostrea gigas. | the oyster vasa-like gene was previously demonstrated to be specifically expressed in germline cells of adult oysters crassostrea gigas. in the present study, this gene was used as a molecular marker to establish the developmental pattern of germline cells during oyster ontogenesis, using whole-mount in situ hybridization and real-time pcr. the oyvlg transcripts appeared to be localized to the vegetal pole of unfertilized oocytes and maternally transmitted to embryos. at early development, these ... | 2004 | 15219870 |
| overview and comparison of lipid-containing semipermeable membrane devices and oysters (crassostrea gigas) for assessing organic chemical exposure. | we performed 20-d, flow-through exposures of lipid-containing semipermeable membrane devices (spmds) and pacific oysters (crassostrea gigas) to three concentrations (nominally 10, 100, and 250 ng/l) of a diverse mixture of polycyclic aromatic hydrocarbons (pahs). exposure water was seawater free of particulates larger than 0.1 microm. the results of these controlled laboratory studies demonstrated that spmds and oysters concentrate the same chemicals but that the relative amounts accumulated are ... | 2004 | 15230313 |
| the effects of decanted sediments on embryogenesis in oysters (crassostrea gigas). | sediments act as sinks for contaminants of natural and anthropogenic origin, constituting a risk to the living organisms. in this study, sediments were collected from three sites on the coast of southwest france. the objective of this research was to determine the effects of sediments on embryonic development of bivalves and to identify precisely when the contaminants affect the embryos and induce them to develop in an abnormal way. the toxicity of decanted sediments and overlying waters were as ... | 2004 | 15230318 |