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physiological change under oshv-1 contamination in pacific oyster crassostrea gigas through massive mortality events on fields.massive mortalities have been observed in france since 2008 on spat and juvenile pacific oysters, crassostrea gigas. a herpes virus called oshv-1, easily detectable by pcr, has been implicated in the mortalities as demonstrated by the results of numerous field studies linking mortality with oshv-1 prevalence. moreover, experimental infections using viral particles have documented the pathogenicity of oshv-1 but the physiological responses of host to pathogen are not well known.201323987141
ostreid herpesvirus 1 infection in farmed pacific oyster larvae crassostrea gigas (thunberg) in korea. 201323957681
identification and characterisation of an ostreid herpesvirus-1 microvariant (oshv-1 µ-var) in crassostrea gigas (pacific oysters) in australia.between november 2010 and january 2011, triploid crassostrea gigas (pacific oysters) cultivated in the georges river, new south wales, experienced >95% mortality. mortalities also occurred in wild diploid c. gigas in the georges river and shortly thereafter in the adjacent parramatta river estuary upstream from sydney harbour. neighbouring saccostrea glomerata (sydney rock oysters) did not experience mortalities in either estuary. surviving oysters were collected to investigate the cause of mort ...201323872855
poly i:c induces a protective antiviral immune response in the pacific oyster (crassostrea gigas) against subsequent challenge with ostreid herpesvirus (oshv-1 μvar).in-vivo studies were carried out to investigate the protective effect of a synthetic viral analogue (poly i:c) against ostreid herpes virus (oshv-1 μvar). pacific oysters (crassostrea gigas) were immune-primed by intramuscular injection of 240 μg of poly i:c or sterile seawater at 1 day prior to infection with oshv-1 μvar. poly i:c injection induced an antiviral state in c. gigas as the percentage of viral-infected oysters at 48 h post infection was significantly lower in the poly i:c treatment ...201323685009
validation of housekeeping genes as internal controls for studying gene expression during pacific oyster (crassostrea gigas) development by quantitative real-time pcr.hatchery-reared larvae of the pacific oyster (crassostrea gigas) often suffer from massive mortality induced by ostreid herpesvirus 1 (oshv-1) infection, indicating the importance of better understanding of oyster immune defense systems. the accuracy of measurements of gene expression levels based on quantitative real-time pcr assays relies on the use of housekeeping genes as internal controls; however, few studies have focused on the selection of such internal controls. in this study, we conduc ...201323357023
development of a real-time pcr for detection of the oyster pathogen nocardia crassostreae based on its homogeneous 16s-23s rrna intergenic spacer region.nocardia crassostreae, the causative agent of pacific oyster nocardiosis (pon), is a gram-positive actinomycete bacterium associated with pacific oyster (crassostrea gigas) mortalities. oysters infected with this bacterium have been reported previously from the west coast of north america and japan. more recently, n. crassostreae was reported in oyster culture areas in the netherlands. in this study, a sensitive real-time pcr for specific detection of n. crassostreae was developed, and the intra ...201323876658
molecular and histological identification of marteilioides infection in suminoe oyster crassostrea ariakensis, manila clam ruditapes philippinarum and pacific oyster crassostrea gigas on the south coast of korea.the oyster ovarian parasite marteilioides chungmuensis has been reported from korea and japan, damaging the oyster industries. recently, marteilioides-like organisms have been identified in other commercially important marine bivalves. in this study, we surveyed marteilioides infection in the manila clam ruditapes philippinarum, suminoe oyster crassostrea ariakensis, and pacific oyster crassostrea gigas, using histology and marteilioides-specific small subunit (ssu) rdna pcr. the ssu rdna sequen ...201324018168
sources of variation of escherichia coli concentrations in bivalve molluscs.bivalve molluscs can concentrate contaminants, including pathogenic microorganisms, from the water column during their normal filter-feeding activity. in the european union, the risk of human and animal faecal contamination in bivalves is estimated by determining the concentration of escherichia coli in time-series samples from production areas. a structured field study was undertaken to determine the extent to which such concentrations varied between sites, sampling occasions and shellfish spec ...201323428551
a new species of gymnophallid (digenea) and an amended diagnosis of the genus gymnophalloides fujita, 1925.morphological and molecular evidence suggest that specimens formerly described as lacunovermis sp. from nacella (patinigera) spp. (patellogastropoda: patellidae) belong to a new species of gymnophalloides fujita, 1925 . based on the new information, they are identified as gymnophalloides nacellae n. sp. the new species differs from gymnophalloides tokiensis, gymnophalloides seoi , and gymnophalloides heardi mainly through the presence of a group of papillae located on the ventral surface between ...201322803608
virus, protozoa and organic compounds decay in depurated oysters.(1) evaluate the dynamic of the depuration process of crassostrea gigas oysters using different ultraviolet doses with different amounts of contaminants (virus, protozoa and organic contaminants) and (2) investigate the morphological changes in the oysters' tissues produced by the depuration procedures.201324184612
the occurrence of haplosporidian parasites, haplosporidium nelsoni and haplosporidium sp., in oysters in ireland.the phylum haplosporidia is a group of obligate protozoan parasites that infect a number of freshwater and marine invertebrates. haplosporidian parasites have caused significant mortalities in commercially important shellfish species worldwide. in this study, haplosporidia were detected in pacific oysters crassostrea gigas originating in ireland and were subsequently identified independently in laboratories both in ireland and in spain as haplosporidium nelsoni. in ireland, h. nelsoni plasmodia ...201323238163
cgmolluscidin, a novel dibasic residue repeat rich antimicrobial peptide, purified from the gill of the pacific oyster, crassostrea gigas.a 5.5 kda antimicrobial peptide consisting of 55 amino acids, cgmolluscidin, was purified from the acidified gill extract of the pacific oyster, crassostrea gigas, by ion-exchange and c18 reversed-phase high performance liquid chromatography. by comparing the n-terminal amino acid sequences and the molecular weight of this peptide with those of other known antimicrobial peptides, it has been revealed that this peptide had no homology with any known peptides. cgmolluscidin showed potent antimicro ...201323711469
impact of weather conditions on escherichia coli accumulation in oysters of the thau lagoon (the mediterranean, france).the thau lagoon shellfish are regularly impacted by microbial pollution of faecal origin, which cause european health standards to be exceeded and closure of the shellfish harvest. the aims of this study were to investigate the impact of weather and hydrological conditions on escherichia coli (e. coli) accumulation factor (af) between water and oysters and to evaluate the relevance of the use of this ratio for the purpose of sanitary risk assessment.201323075079
persistence of vibrio parahaemolyticus in the pacific oyster, crassostrea gigas, is a multifactorial process involving pili and flagella but not type iii secretion systems or phase variation.vibrio parahaemolyticus can resist oyster depuration, suggesting that it possesses specific factors for persistence. we show that type i pili, type iv pili, and both flagellar systems contribute to v. parahaemolyticus persistence in pacific oysters whereas type iii secretion systems and phase variation do not.201323475619
responses of b-esterase enzymes in oysters (crassostrea gigas) transplanted to pesticide contaminated bays form the ebro delta (ne, spain).marine bivalves such as oysters are widely used as bioindicators to monitor marine coastal pollution. this study aimed to use b-esterase activity responses in oysters (crassostrea gigas) cultured in ebro delta bays to monitor environmental effects of pesticides. the b esterases investigated were acetylcholinesterase, propionylcholinesterase, and carboxylesterase and their activities were measured in adductor muscle and gills from oysters transplanted in ebro delta bays where the are traditionall ...201323168234
study of the antioxidant capacity in gills of the pacific oyster crassostrea gigas in link with its reproductive investment.energy allocation principle is a core element of life-history theory in which "the cost of reproduction" corresponds to an acceleration of senescence caused by an increase in reproductive investment. in the "theory of aging", senescence is mainly due to the degradation of lipids, proteins and dna by reactive oxygen species (ros), by-products of oxidative metabolism. some studies have shown that oxidative stress susceptibility could be a cost of reproduction. the present study investigates the ef ...201323073513
regulation of a truncated isoform of amp-activated protein kinase α (ampkα) in response to hypoxia in the muscle of pacific oyster crassostrea gigas.amp-activated protein kinase α (ampkα) is a key regulator of energy balance in many model species during hypoxia. in a marine bivalve, the pacific oyster crassostrea gigas, we analyzed the protein content of adductor muscle in response to hypoxia during 6 h. in both smooth and striated muscles, the amount of full-length amp-activated protein kinase α (ampkα) remained unchanged during hypoxia. however, hypoxia induced a rapid and muscle-specific response concerning truncated isoforms of ampkα. in ...201323354411
heavy metal content in oysters (crassostrea gigas) cultured in the ebro delta in catalonia, spain.the aim of this study was to determine heavy metal content (as, cd, cu, hg, cd, pb, and zn) in oysters transplanted in ebro delta bays (alfacs and fangar) where oysters are traditionally cultured for human consumption. metal body burdens were monitored weekly during the period of maximal agriculture activity from may to june in 2008 and 2009. results indicate that regardless of the high levels of metals reported in biota living in ebro river, metal levels in oysters from both bays were similar t ...201323325313
in situ distribution and characterization of the organic content of the oyster shell crassostrea gigas (mollusca, bivalvia).cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". in order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. the left and right valves of the oyster shell crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular. the shell layers of juvenile c. gigas are studied using a variety of ...201323022314
species sensitivity distribution evaluation for chronic nickel toxicity to marine organisms.in europe, the european union's existing substances regulation (eec 793/93), the reach regulation, and water framework directive all share common guidance for conducting environmental effects assessments, which can be further used to derive predicted no effect concentrations (pnecs) and environmental quality standards (eqs) for chemical substances. to meet the criteria for using a species sensitivity distribution (ssd) in the effects assessment of ni for marine organisms, chronic toxicity data f ...201323553986
sequence polymorphism and expression variability of crassostrea gigas immune related genes discriminate two oyster lines contrasted in term of resistance to summer mortalities.summer mortalities of crassostreagigas are a major concern in oyster aquaculture. they are the result of a complex interaction between the host, pathogens and environmental factors. oyster genetics have been identified as an essential determinant of oyster susceptibility to summer mortalities. as the capability of oysters to circumvent diseases depends in part on their immune defenses, we aimed to analyze the gene expression and sequence polymorphism of 42 immune related genes in two oyster line ...201324086661
genetic and genotoxic impacts in the oyster crassostrea gigas exposed to the harmful alga alexandrium minutum.genotoxic, genetic and behavioral impacts of the paralytic shellfish toxin (pst)-producing alga alexandrium minutum on the oyster crassostrea gigas were assessed using rapd-pcr, qpcr and valve activity recording. oysters were exposed to a dose mimicking an algal bloom (≈1600 cells ml(-1)) for 48 h. results indicate a rapid and sustained behavioral disturbance. animals remained open but exhibited reduced valve-opening amplitude, correlated to the amount of toxin accumulated in the digestive gland ...201323933679
sex-specific regulation of amp-activated protein kinase (ampk) in the pacific oyster crassostrea gigas.the hermaphrodite pacific oyster crassostrea gigas displays a high energy allocation to reproduction. we studied the expression of amp-activated protein kinase (ampk) during gametogenesis in the gonad and characterized the mrna sequences of the ampk subunits: the ampk alpha mrna sequence was previously characterized; we identified ampk beta, ampk gamma, and mrnas of putative ampk-related targets following bioinformatics mining on existing genomic resources. we analyzed the mrna expression of the ...201323926284
impacts of long-line aquaculture of pacific oysters (crassostrea gigas) on sulfate reduction and diffusive nutrient flux in the coastal sediments of jinhae-tongyeong, korea.we investigated the environmental impacts of long-line aquaculture of pacific oysters (crassostrea gigas) on sediment geochemistry and carbon oxidation by sulfate reduction and diffusive benthic nutrient flux in a coastal ecosystem in korea. inventories of the nh4(+) and hpo4(2-) at the farm site were 7.7-11.5 and 1.8-8.0 times higher, respectively, than those at a reference site. sulfate reduction rates (srrs) at the oyster farm were 2.4-5.2 times higher than srrs at the reference site. the srr ...201323896400
dna methylation is crucial for the early development in the oyster c. gigas.in vertebrates, epigenetic modifications influence gene transcription, and an appropriate dna methylation is critical in development. indeed, a precise temporal and spatial pattern of early gene expression is mandatory for a normal embryogenesis. however, such a regulation and its underlying mechanisms remain poorly understood in more distant organisms such as lophotrochozoa. thus, despite dna in the oyster genome being methylated, the role of dna methylation in development is unknown. to clarif ...201323877618
spatial distribution of mortality in pacific oysters crassostrea gigas: reflection on mechanisms of oshv-1 transmission.the ostreid herpesvirus oshv-1 has the potential to devastate pacific oyster crassostrea gigas culture in australia as it has done in many other countries, highlighting the need for a better understanding of disease expression and transmission. the aim of this study was to assess the spatial distribution of oshv-1-associated mortalities in one of only two infected areas in australia, woolooware bay (botany bay, new south wales). in october 2011, healthy sentinel pacific oysters were placed in 3 ...201323872856
the presence of genogroup ii norovirus in retail shellfish from seven coastal cities in china.noroviruses (novs) are commonly occurring pathogens that cause gastroenteritis. outbreaks of viral diseases have often been ascribed to the consumption of contaminated shellfish. our objective was to evaluate the presence and contamination levels of nov in shellfish sold at seafood markets in china. we tested 840 shellfish samples (crassostrea gigas, mytilus edulis, azumapecten farreri, sinonovacula constricta, scapharca subcrenata, ruditapes philippinarum) that were collected from seven cities ...201323412724
do uk coastal and estuarine water samples pose a phototoxic threat?many studies have investigated phototoxicity under controlled laboratory conditions, however, few have actually demonstrated it occurring in environmental samples. here we report on the potential for uk marine coastal waters to demonstrate phototoxicity when tested using the oyster embryo (crassostrea gigas) bioassay in the presence uv light. subsurface water, sea surface microlayer samples and subsurface water samples that had been extracted through solid phase extraction (spe) columns were ana ...201323398746
determination of the recovery efficiency of cryptosporidium oocysts and giardia cysts from seeded bivalve mollusks.the intestinal parasites cryptosporidium and giardia are transmitted by water and food and cause human gastroenteritis. filter-feeding bivalve mollusks, such as oysters and mussels, filter large volumes of water and thus concentrate such pathogens, which makes these bivalves potential vectors of disease. to assess the risk of infection from consumption of contaminated bivalves, parasite numbers and parasite recovery data are required. a modified immunomagnetic separation (ims) procedure was used ...201323317862
rapid mitochondrial adjustments in response to short-term hypoxia and re-oxygenation in the pacific oyster, crassostrea gigas.as oxygen concentrations in marine coastal habitats can fluctuate rapidly and drastically, sessile marine organisms such as the oyster crassostrea gigas can experience marked and rapid oxygen variations. in this study, we investigated the responses of oyster gill mitochondria to short-term hypoxia (3 and 12 h, at 1.7 mg o2 l(-1)) and subsequent re-oxygenation. mitochondrial respiratory rates (states 3 and 4 stimulated by glutamate) and phosphorylation efficiency [respiratory control ratio (rcr) ...201323307802
biomonitoring of metals under the water framework directive: detecting temporal trends and abrupt changes, in relation to the removal of pollution sources.temporal trends in metal concentrations, i.e. ag, cd, cu, cr, hg, ni, pb and zn, measured in soft tissues of mytilus galloprovincialis mussels and crassostrea gigas oysters collected from estuarine waters within the basque country (bay of biscay), have been investigated to determine if actions undertaken have improved the environmental quality of rivers and estuaries. data compiled between 1990 and 2010 have been analysed statistically, applying the mann-kendall and the mann-whitney-wilcoxon tes ...201323279998
effects of glyphosate-based herbicides on embryo-larval development and metamorphosis in the pacific oyster, crassostrea gigas.pesticides may be involved in oyster summer mortality events, not necessarily as a single causative agent but as an additional stressor. in this context, the present study aimed to assess the toxicity of glyphosate, its by-product, aminomethylphosphonic acid (ampa) and two commercial formulations, roundup express(®) (r(ex)) and roundup allées et terrasses(®) (r(at)), containing glyphosate as the active ingredient, on the early life stages of the pacific oyster, crassostrea gigas. the embryotoxic ...201323277103
management of domoic acid monitoring in shellfish from the catalan coast.monitoring of amnesic shellfish poisoning (asp) toxins in shellfish from the catalan coast started in 2001. no asp toxins were detected in any of the analyses performed before 2008. on 22 january 2008, domoic acid (da) was detected in donax trunculus (0.5 mg kg(-1)) and confirmed by rapid resolution liquid chromatography-tandem mass spectrometry (0.6 mg kg(-1)). a total of 974 shellfish samples were analyzed from january 2008 to december 2011, covering all the catalan production areas and the mo ...201323275095
shotgun proteomics as a viable approach for biological discovery in the pacific oyster.shotgun proteomics offers an efficient means to characterize proteins in a complex mixture, particularly when sufficient genomic resources are available. in order to assess the practical application of shotgun proteomics in the pacific oyster (crassostrea gigas), liquid chromatography coupled with tandem mass spectrometry was used to characterize the gill proteome. using information from the recently published pacific oyster genome, 1043 proteins were identified. biological samples (n = 4) and c ...201327293593
identification and functional characterization of mre-binding transcription factor (mtf) in crassostrea gigas and its conserved role in metal-induced response.the full-length cdna that encodes the mre-binding transcription factor (mtf) was cloned from the pacific oyster (crassostrea gigas) using reverse transcription polymerase chain reaction and the rapid amplification of cdna ends. the cgmtf cdna sequence is 2892 bp long, with a 2508 bp open reading frame that encodes an 835-amino acid polypeptide. multiple alignment revealed that cgmtf has four putative zinc finger-like regions in cgmtf with three c2c2-type zinc fingers and one c2h2-type zinc finge ...201323271123
arsenic in marine sediments from french mediterranean ports: geochemical partitioning, bioavailability and ecotoxicology.this work investigates arsenic mobility, bioavailability and toxicity in marine port sediments using chemical sequential extraction and laboratory toxicity tests. sediment samples were collected from two different mediterranean ports, one highly polluted with arsenic and other inorganic and organic pollutants (estaque port (est)), and the other one, less polluted, with a low arsenic content (saint mandrier port (sm)). arsenic distribution in the solid phase was studied using a sequential extract ...201323267728
pacific oyster-derived polysaccharides enhance antigen-specific t helper (th)1 immunity in vitro and in vivo.bacterial and fungal polysaccharides are well known as being immunoactive. however, evidence pertaining to the immunomodulatory activity of polysaccharides derived from animal origins is scarce. this study investigated the effects of an extract of oyster (crassostrea gigas) polysaccharides (ops) on antigen-specific t-cell immunity. for in vitro studies, ovalbumin (ova)-primed splenocytes were exposed to ops and re-stimulated with ova in culture to induce antigen-specific responses. for in vivo s ...201323237389
allograft inflammatory factor-1 stimulates hemocyte immune activation by enhancing phagocytosis and expression of inflammatory cytokines in crassostrea gigas.allograft inflammatory factor-1 (aif-1) is a calcium-binding cytokine associated with immune cell activation and inflammatory response. presently, we have identified and characterized an aif-1 in a marine bivalve mollusk, crassostrea gigas, and designated it as cgaif-1. the full-length cgaif-1 cdna is 794 bp, encoding a protein of 149 amino acids with two conserved ef hand ca(2+)-binding motifs. cgaif-1 is constitutively expressed in various tissues with enriched expression in hemocytes. moreove ...201323419879
taxonomic identity of a tetrodotoxin-accumulating ribbon-worm cephalothrix simula (nemertea: palaeonemertea): a species artificially introduced from the pacific to europe.we compared the anatomy of the holotype of the palaeonemertean cephalothrix simula ( iwata, 1952 ) with that of the holotypes of cephalothrix hongkongiensis sundberg, gibson and olsson, 2003 and cephalothrix fasciculus ( iwata, 1952 ), as well as additional specimens from fukue (type locality of c. simula) and hiroshima, japan. while there was no major morphological discordance between these specimens, we found discrepancies between the actual morphology and some statements in the original descr ...201324199864
purification of a novel peptide derived from a shellfish, crassostrea gigas, and evaluation of its anticancer property.a novel anticancer peptide was purified from crassostrea gigas and investigated for its cytotoxic activity. to prepare the peptide, eight proteases were employed for enzymatic hydrolysis. flavourzyme hydrolysate, which showed clearly superior cytotoxic activity on prostate cancer cells, was further purified using a membrane system and consecutive chromatographic methods. finally, a novel anticancer peptide was obtained, and the sequence was partially purified as his-phe-asn-ile-gly-asn-arg-cys-l ...201324199654
molecular characterization and expression analysis of chitinase from the pacific oyster crassostrea gigas.chitinases are necessary enzymes supporting functions as a host defense factor against chitin-coated pathogens. they also function as a digestive enzyme for the hydrolysis of dietary chitin. we conducted characterization and assessed the tissue expression of the encoding gene of a chitinase (ec 3.2.1.14), cg-chit1, and the production of recombinant protein of cg-chit1, from the pacific oyster, crassostrea gigas. chitinase activity in mantle extracts was detected to a marked degree in samples col ...201323507628
proteomic identification of protein associated to mature spermatozoa in the pacific oyster crassostrea gigas.knowledge of sperm maturation process is limited in the pacific oyster crassostrea gigas and major factors of fertilization success of this free spawning animal are unknown. we investigated proteins associated to spermatozoa by analyzing two cellular fractions obtained from a 40-80% percoll gradient fractioning of germ cell of mature male gonads. mature spermatozoa were enriched in the lower percoll fraction while the upper fraction contained less mature or earlier germ cells. a 2-de proteomic a ...201323466311
population genomics shed light on the demographic and adaptive histories of european invasion in the pacific oyster, crassostrea gigas.crassostrea gigas originated from the pacific coast of asia, but was introduced into several european countries in the early 1970s. natural populations have now spread across the length of the western seaboard of europe. to elucidate the demographic and selective processes at play during this rapid expansion, genome-scan analysis was performed on different populations. high diversities and low differentiation were observed overall, but significant genetic differentiation was found among newly es ...201324187588
identification of a tyrosinase gene potentially involved in early larval shell biogenesis of the pacific oyster crassostrea gigas.the larval shell emerges early in embryogenesis of mollusks, but the detailed mechanisms of its biogenesis remain to be determined. in this study, we cloned a tyrosinase gene (cgi-tyr1) that potentially functioned in larval shell biogenesis from the pacific oyster crassostrea gigas, a worldwide bivalve species. sequence analysis of cgi-tyr1 revealed that it had typical copper-binding domains and a signal peptide. through whole mount in situ hybridization and an electron scanning microscopic obse ...201323897397
environmental concentrations of irgarol, diuron and s-metolachlor induce deleterious effects on gametes and embryos of the pacific oyster, crassostrea gigas.irgarol and diuron are the most representative "organic booster biocides" that replace organotin compounds in antifouling paints, and metolachlor is one of the most extensively used chloroacetamide herbicides in agriculture. the toxicity of s-metolachlor, irgarol and diuron was evaluated in pacific oyster (crassostrea gigas) gametes or embryos exposed to concentrations of pesticides ranging from 0.1× to 1000×, with 1× corresponding to environmental concentrations of the three studied pesticides ...201323727205
larval and post-larval stages of pacific oyster (crassostrea gigas) are resistant to elevated co2.the average ph of surface oceans has decreased by 0.1 unit since industrialization and is expected to decrease by another 0.3-0.7 units before the year 2300 due to the absorption of anthropogenic co2. this human-caused ph change is posing serious threats and challenges to the pacific oyster (crassostrea gigas), especially to their larval stages. our knowledge of the effect of reduced ph on c. gigas larvae presently relies presumptively on four short-term (<4 days) survival and growth studies. us ...201323724027
effects of rna interference-mediated knock-down of hypoxia-inducible factor-α on respiratory burst activity of the pacific oyster crassostrea gigas hemocytes.in mammals, hypoxia-inducible factor-1 α (hif-1α) is known to play important roles not only in oxygen homeostasis but also in innate immune responses. in this study, to assess the functional role of hif-α in respiratory burst activity of crassostrea gigas hemocytes, oysters were injected with hif-α- or green fluorescent protein (gfp)-targeted-long double-stranded rnas (dsrnas), and at 1, 3, and 7 days post-injection, knock-down of c. gigas hif-α expression and production of reactive oxygen speci ...201323680843
high mobility group box 1 can enhance nf-κb activation and act as a pro-inflammatory molecule in the pacific oyster, crassostrea gigas.high-mobility group box 1 (hmgb1), a highly conserved dna-binding protein, is involved in nucleosome formation and transcriptional regulation, and can also act as an extracellular cytokine to trigger inflammation and immune responses. in this study, we identified a hmgb1 gene (hereafter designated as cghmgb1) in the pacific oyster crassostrea gigas. the full-length cghmgb1 cdna is 833 bp including 5' and 3'-untranslated regions (utrs) of 145 and 79 bp, respectively, and an open reading frame (or ...201323583349
genome and transcriptome analyses provide insight into the euryhaline adaptation mechanism of crassostrea gigas.the pacific oyster, crassostrea gigas, has developed special mechanisms to regulate its osmotic balance to adapt to fluctuations of salinities in coastal zones. to understand the oyster's euryhaline adaptation, we analyzed salt stress effectors metabolism pathways under different salinities (salt 5, 10, 15, 20, 25, 30 and 40 for 7 days) using transcriptome data, physiology experiment and quantitative real-time pcr.201323554902
oyster sex determination is influenced by temperature - first clues in spat during first gonadic differentiation and gametogenesis.the sex-determining system of crassostrea gigas is still poorly known, especially regarding the potential influence of temperature. in order to address this question, mrna expressions of actors of the molecular cascade (cg-dml, cg-soxe, cg-β-catenin, cg-foxl2/cg-foxl2os) and of oyvlg, a germ cell marker, were investigated by real-time pcr in spat grown at different temperatures (18, 22, 25 and 28°c). in parallel, gonadic differentiation, gametogenesis and sex ratios were assessed by histology at ...201323416889
the first evidence of positive selection in peptidoglycan recognition protein (pgrp) genes of crassostrea gigas.the oyster crassostrea gigas is thought to have developed effective immunity to potentially harmful pathogens while under continuous exposure to marine microorganisms; however, the evolutionary mechanisms by which such immunity developed has not been understood. to understand the evolution of immunity, we characterized the family of peptidoglycan recognition proteins in the oyster (cgpgrps). these proteins are crucial pattern recognition receptors for peptidoglycans (pgns) and thereby, for activ ...201323416224
diarrhetic shellfish toxins and other lipophilic toxins of human health concern in washington state.the illness of three people in 2011 after their ingestion of mussels collected from sequim bay state park, washington state, usa, demonstrated the need to monitor diarrhetic shellfish toxins (dsts) in washington state for the protection of human health. following these cases of diarrhetic shellfish poisoning, monitoring for dsts in washington state became formalized in 2012, guided by routine monitoring of dinophysis species by the soundtoxins program in puget sound and the olympic region harmfu ...201323760013
development of genetic markers for triploid verification of the pacific oyster, crassostrea gigas.the triploid pacific oyster, which is produced by mating tetraploid and diploid oysters, is favored by the aquaculture industry because of its better flavor and firmer texture, particularly during the summer. however, tetraploid oyster production is not feasible in all oysters; the development of tetraploid oysters is ongoing in some oyster species. thus, a method for ploidy verification is necessary for this endeavor, in addition to ploidy verification in aquaculture farms and in the natural en ...201325049868
characterizations of shell and mantle edge pigmentation of a pacific oyster, crassostrea gigas, in korean peninsula.the objectives of this study were to investigate color patterns of shell and mantle edge pigmentation of a pacific oyster, c. gigas, and to estimate variance components of the two colors. a sample of 240 f0 oysters was collected from six aquaculture farms in tongyeong, korea to measure shell color and mantle edge pigmentation. among the f0s, male and female individuals with black (white) shell and black (white) mantle edge were selected and mated to generate three f1 full-sib black (white) cross ...201325049755
the density and spatial arrangement of the invasive oyster crassostrea gigas determines its impact on settlement of native oyster larvae.understanding how the density and spatial arrangement of invaders is critical to developing management strategies of pest species. the pacific oyster, crassostrea gigas, has been translocated around the world for aquaculture and in many instances has established wild populations. relative to other species of bivalve, it displays rapid suspension feeding, which may cause mortality of pelagic invertebrate larvae. we compared the effect on settlement of sydney rock oyster, saccostrea glomerata, lar ...201324455120
a glycoprotein in shells of conspecifics induces larval settlement of the pacific oyster crassostrea gigas.settlement of larvae of crassostrea gigas on shell chips (sc) prepared from shells of 11 different species of mollusks was investigated. furthermore, the settlement inducing compound in the shell of c. gigas was extracted and subjected to various treatments to characterize the chemical cue. c. gigas larvae settled on sc of all species tested except on patinopecten yessoensis and atrina pinnata. in sc of species that induced c. gigas larvae to settle, settlement was proportionate to the amount of ...201324349261
survival rates with time course of frozen-thawed pacific oyster larvae in indoor rearing system.post-thawed larval rearing in pacific oyster crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. the highest survival rate and larval activity index (lai) of post-thawed larvae were obtained from the permeation in 0.2 m sucrose and 2.0 m ethylene glycol (eg) at -1°c/min in freezing speed showing the survival rates just after thawing of 63.8% in trochophore, 84.1% in d-shaped veliger and 56.3% in early umbo veliger. in post-tha ...201325949149
brain acetylcholinesterase activity in shiner perch (cymatogaster aggregata) and juvenile chinook salmon (oncorhynchus tshawytscha) after application of carbaryl to control burrowing shrimp within willapa bay, washington.carbaryl has been applied in willapa bay, washington, for five decades to control burrowing shrimp (neotrypaea californiensis and upogebia pugettensis) on commercial oyster (crassostrea gigas) beds. concerns about effects on nontarget species, including fishes, have led to restrictions in use despite a lack of data on in situ exposure. we measured brain acetylcholinesterase (ache) activity in adult shiner perch (cymatogaster aggregata) and juvenile chinook salmon (oncorhynchus tshawytscha) after ...201324042340
genomics study of the exposure effect of gymnodinium catenatum, a paralyzing toxin producer, on crassostrea gigas' defense system and detoxification genes.crassostrea gigas accumulates paralytic shellfish toxins (pst) associated with red tide species as gymnodinium catenatum. previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in c. gigas stress response.201324039751
detection of a new oshv-1 dna strain in the healthy pacific oyster, crassostrea gigas thunberg, from the gulf of california. 201324033643
comparative cryopreservation study of trochophore larvae from two species of bivalves: pacific oyster (crassostrea gigas) and blue mussel (mytilus galloprovincialis).oysters and mussels are among the most farmed species in aquaculture industry around the world. the aim of this study was to test the toxicity of cryoprotective agents to trochophore larvae from two different species of bivalves and develop an improved cryopreservation protocol to ensure greater efficiency in the development of cryopreserved trochophores (14 h old oyster larvae and 20 h old mussel larvae) to normal d-larvae for future developments of hatchery spat production. the cryopreservatio ...201323999078
predominant intragenic methylation is associated with gene expression characteristics in a bivalve mollusc.characterization of dna methylation patterns in the pacific oyster, crassostrea gigas, indicates that this epigenetic mechanism plays an important functional role in gene regulation and may be involved in the regulation of developmental processes and environmental responses. however, previous studies have been limited to in silico analyses or characterization of dna methylation at the single gene level. here, we have employed a genome-wide approach to gain insight into how dna methylation suppor ...201324282674
exposure to the neurotoxic dinoflagellate, alexandrium catenella, induces apoptosis of the hemocytes of the oyster, crassostrea gigas.this study assessed the apoptotic process occurring in the hemocytes of the pacific oyster, crassostrea gigas, exposed to alexandrium catenella, a paralytic shellfish toxins (psts) producer. oysters were experimentally exposed during 48 h to the toxic algae. psts accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. results show a significant increase of the number of ...201324317471
identification of molecular and physiological responses to chronic environmental challenge in an invasive species: the pacific oyster, crassostrea gigas.understanding the environmental responses of an invasive species is critical in predicting how ecosystem composition may be transformed in the future, especially under climate change. in this study, crassostrea gigas, a species well adapted to the highly variable intertidal environment, was exposed to the chronic environmental challenges of temperature (19 and 24°c) and ph (ambient seawater and a reduction of 0.4 ph units) in an extended 3-month laboratory-based study. physiological parameters w ...201324223268
disturbance induced decoupling between host genetics and composition of the associated microbiome.studies of oyster microbiomes have revealed that a limited number of microbes, including pathogens, can dominate microbial communities in host tissues such as gills and gut. much of the bacterial diversity however remains underexplored and unexplained, although environmental conditions and host genetics have been implicated. we used 454 next generation 16s rrna amplicon sequencing of individually tagged pcr reactions to explore the diversity of bacterial communities in gill tissue of the invasiv ...201324206899
extracellular and intracellular acid-base status with regard to the energy metabolism in the oyster crassostrea gigas during exposure to air.the acid-base status of extra- and intracellular fluids was studied in relation to the anaerobic energy metabolism in the adductor muscle, mantle, gills, and heart of the marine bivalve crassostrea gigas after exposure to air for periods of 2, 4, 8, 12, 24, and 48 h. such exposure was found to cause a significant reduction in the ph in the hemolymph (ph(e)) within the first 4 h. the decrease in the phe was accompanied by elevated pco2 values, causing [hco3-] to rise (respiratory acidosis). there ...201315887084
a complementary method for production of tetraploid crassostrea gigas using crosses between diploids and tetraploids with cytochalasin b treatments.we present a new method to produce tetraploid crassostrea gigas by cytochalasin b inhibition of polar body 2 expulsion in diploid females crossed with tetraploid males. this offers a means of direct introgression of genetic characters from selected diploid to tetraploid lines, avoiding a triploid step. offspring larval ploidy shifted over time and depended on size, with tetraploids more frequent among the smaller larvae and triploids among the large. viable tetraploids were found at 4 and 6 mont ...201315906113
differential production of active oxygen species in photo-symbiotic and non-symbiotic bivalves.we investigated the generation of active oxygen species in the bivalves, crassostrea gigas, fulvia mutica and tridacna crocea in order to understand the defensive mechanisms in giant clams that allow a stable association with symbiotic zooxanthellae. c. gigas produced active oxygens, superoxide anion and nitric oxide upon stimulation by phorbol myristate acetate. f. mutica generated a little amount of superoxide anion and nitric oxide, and contained significant phenoloxidase activity which catal ...20139639085
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 ...201312908027
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 ...201312408628
cholesterol addition and removal in pacific oyster oocytes does not improve cryopreservation success.the optimal cholesterol content in cells could provide the benefit of lowering or eliminating the lipid phase transition temperature, while maintaining membrane fluidity and strength; thus, making cells less sensitive to chilling injury and more amenable to cryopreservation. such effects were shown in some gametes and embryos of certain mammalian species, however, some other cell types, benefited from cholesterol removal. the experiments developed in this study aimed to determine the effect of i ...201418946553
a microbial spoilage profile of half shell pacific oysters (crassostrea gigas) and sydney rock oysters (saccostrea glomerata).this study aimed to assess bacterial spoilage of half shell pacific and sydney rock oysters during storage using microbial culture and 16s rrna pyrosequencing. odour and ph of oyster meats were also investigated. estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. during storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for pacific oysters ...201424290646
epigenetic features in the oyster crassostrea gigas suggestive of functionally relevant promoter dna methylation in invertebrates.dna methylation is evolutionarily conserved. vertebrates exhibit high, widespread dna methylation whereas invertebrate genomes are less methylated, predominantly within gene bodies. dna methylation in invertebrates is associated with transcription level, alternative splicing, and genome evolution, but functional outcomes of dna methylation remain poorly described in lophotrochozoans. recent genome-wide approaches improve understanding in distant taxa such as molluscs, where the phylogenetic posi ...201424778620
molecular cloning and characterization of socs-2 from manila clam ruditapes philippinarum.suppressor of cytokine signaling (socs) family members are key regulators of immunological homeostasis. in this study, we have discovered the socs-2 member from manila clam ruditapes philippinarum and further analyzed its immune responses against lipopolysaccharide (lps) and polyinosinic:polycytidylic acid (poly i:c). amino acid sequence of rpsocs-2 consists of cytokine inducible src homology 2 (sh2) and socs box domains similar to vertebrate socs counterparts. it has the highest amino acid iden ...201424378684
comparative responses of sperm cells and embryos of pacific oyster (crassostrea gigas) to exposure to metolachlor and its degradation products.metolachlor is one of the most intensively used chloroacetanilide herbicides in agriculture. consequently, it has been frequently detected in coastal waters as well as its major degradation products, metolachlor ethane sulfonic acid (mesa) and metolachlor oxanilic acid (moa) which are encountered at higher concentrations than metolachlor. although a few studies of metolachlor toxicity have been conducted on marine organisms, little is known about the environmental toxicity of metolachlor degrada ...201424378469
the identification and characteristics of immune-related micrornas in haemocytes of oyster crassostrea gigas.micrornas (mirnas) represent a class of small ncrnas that repress gene expression on the post-transcriptional level by the degradation or translation inhibition of target mrna.201424516648
an egfr gene of the pacific oyster crassostrea gigas functions in wound healing and promotes cell proliferation.the epidermal growth factor receptor (egfr) is an important receptor tyrosine kinase member in animals, which plays versatile functions in development, growth, tissue regeneration etc. current knowledge on egfr is poor in bivalve mollusks. in this study, we cloned and analyzed an egfr gene from the pacific oyster crassostrea gigas (cgegfr). a 5,731 bp full-length cdna of cgegfr was obtained, encoding a peptide with 1,494 amino acids which exhibited a typical egfr structure, including an extracel ...201424469720
mitochondrial activity, hemocyte parameters and lipid composition modulation by dietary conditioning in the pacific oyster crassostrea gigas.several parameters can affect membrane lipid composition in bivalves, including diet. although two fatty acids (fa) 22:6n-3 and 20:5n-3 are essential membrane components, they are sparingly synthesized by bivalves and must be obtained from their diet. here, effects of dietary modifications of membrane lipid composition were studied at both cellular and subcellular levels in the oyster crassostrea gigas. to this end, we compared oysters fed two monoalgal diets that differed markedly in their fa c ...201424441864
investigating the response of cuproproteins from oysters (crassostrea gigas) after waterborne copper exposure by metallomic and proteomic approaches.the pacific oyster (crassostrea gigas), a good model for studying biomineralization and coastal environmental change, was used to study the expression of cuproproteins after waterborne cu exposure (3 μg cu l(-1)) similarly to the arcachon bay aquatic environment. cuproproteins in oyster cytosols were analyzed by gel electrophoresis (non-denaturing page and sds 2-de), laser ablation inductively coupled plasma mass spectrometry (la-icp ms) and electrospray ionization mass spectrometry (esi-ms). th ...201424430468
exploring the hologenome concept in marine bivalvia: haemolymph microbiota as a pertinent source of probiotics for aquaculture.haemolymph-associated microbiota of marine bivalves was explored for antibacterial activity against important aquaculture pathogens. a collection of 843 strains were cultured from the haemolymph of four bivalve species (crassostrea gigas, mytilus edulis, pecten maximus and tapes rhomboides) collected by deep-sea diving in the glenan archipelago (france). cell-free culture supernatants were investigated for antibacterial activity using the well-diffusion assay. about 3% of haemolymph-associated c ...201424286558
the jumonji gene family in crassostrea gigas suggests evolutionary conservation of jmj-c histone demethylases orthologues in the oyster gametogenesis and development.jumonji (jmj) proteins are histone demethylases, which control the identity of stem cells. jmj genes were characterized from plants to mammals where they have been implicated in the epigenetic regulation of development. despite the pacific oyster crassostrea gigas representing one of the most important aquaculture resources worldwide, the molecular mechanisms governing the embryogenesis and reproduction of this lophotrochozoan species remain poorly understood. however, annotations in the c. giga ...201424406622
roles of extracellular ions and ph in 5-ht-induced sperm motility in marine bivalve.factors that inhibit and stimulate the initiation of sperm motility were determined for manila clam (ruditapes philippinarum), pacific oyster (crassostrea gigas), and japanese scallop (patinopecten yessoensis). compared with artificial seawater (asw), serotonin (5-hydroxytryptamine creatinine sulfate, 5-ht) could fully trigger sperm motility and increase sperm velocity and motility duration. sperm motility was decreased in asw at ph 6.5-7.0 and suppressed at ph 4.0. in manila clam and pacific oy ...201424398874
multiple ferritin subunit genes of the pacific oyster crassostrea gigas and their distinct expression patterns during early development.multiple ferritin subunit genes are reported in mollusks, but they have not been systematically classified. based on the recently published whole genome sequence, we screened out the four ferritin subunit genes (cgi-fer1-cgi-fer4) from the pacific oyster crassostrea gigas. the four genes were predicted to encode two non-secretory and two secretory peptides. further phylogenetic analyses revealed two groups of non-secretory and secretory ferritin subunits in mollusks. this differs dramatically fr ...201424836508
spatial and temporal dynamics of mass mortalities in oysters is influenced by energetic reserves and food quality.although spatial studies of diseases on land have a long history, far fewer have been made on aquatic diseases. here, we present the first large-scale, high-resolution spatial and temporal representation of a mass mortality phenomenon cause by the ostreid herpesvirus (oshv-1) that has affected oysters (crassostrea gigas) every year since 2008, in relation to their energetic reserves and the quality of their food. disease mortality was investigated in healthy oysters deployed at 106 locations in ...201424551106
identification and functional characterization of two executioner caspases in crassostrea gigas.caspase-3 and caspase-7 are two key effector caspases that play important roles in apoptotic pathways that maintain normal tissue and organ development and homeostasis. however, little is known about the sequence, structure, activity, and function of effector caspases upon apoptosis in mollusks, especially marine bivalves. in this study, we investigated the possible roles of two executioner caspases in the regulation of apoptosis in the pacific oyster crassostrea gigas. a full-length caspase-3-l ...201424551213
pesticide residues, heavy metals, and dna damage in sentinel oysters crassostrea gigas from sinaloa and sonora, mexico.pesticides and heavy metals were analyzed in sentinel crassostrea gigas oysters placed in six aquaculture sites close to a contaminated agricultural region. each site was sampled twice. tests revealed the presence of organochlorine (oc) pesticides in the oysters at concentrations varying from 31.8 to 72.5 μg/kg for gamma-hexachlorocyclohexane (γ-hch); from 1.2 to 3.1 μg/kg for dichlorodiphenyldichloroethylene (4,4-dde); from 1.6 to 2.3 μg/kg for endosulfan i; and from 1.4 to 41.2 μg/kg for endos ...201424555676
effects of acute exposures to mecoprop, mecoprop-p and their biodegradation product (2-mcp) on the larval stages of the pacific oyster, crassostrea gigas.studies have shown that pesticides are sometimes detected at rather high levels in seawater and it has been suggested that these chemical compounds could act as additional stress factor for oysters cultured in coastal environments. the effects of pesticides on marine molluscs could be particularly harmful in the early stages which correspond to critical life stages. this study aimed to assess the effects of mecoprop, mecoprop-p and their degradation compound 2-methyl-4-chlorophenol on two larval ...201424321574
development of snp-genotyping arrays in two shellfish species.use of snps has been favoured due to their abundance in plant and animal genomes, accompanied by the falling cost and rising throughput capacity for detection and genotyping. here, we present in vitro (obtained from targeted sequencing) and in silico discovery of snps, and the design of medium-throughput genotyping arrays for two oyster species, the pacific oyster, crassostrea gigas, and european flat oyster, ostrea edulis. two sets of 384 snp markers were designed for two illumina goldengate ar ...201424447767
cellular and biochemical responses of the oyster crassostrea gigas to controlled exposures to metals and alexandrium minutum.effects of simultaneous exposure of pacific oyster, crassostrea gigas, to both a harmful dinoflagellate that produces paralytic shellfish toxins (pst), alexandrium minutum, and cadmium (cd) and copper (cu), were assessed. oysters were exposed to a mix of cd-cu with two different diets (i.e. a. minutum or tisochrysis lutea) and compared to control oysters fed a. minutum or t. lutea, respectively, without metal addition. metals and pst accumulations, digestive gland lipid composition, and cellular ...201424418747
vestigialization of an allosteric switch: genetic and structural mechanisms for the evolution of constitutive activity in a steroid hormone receptor.an important goal in molecular evolution is to understand the genetic and physical mechanisms by which protein functions evolve and, in turn, to characterize how a protein's physical architecture influences its evolution. here we dissect the mechanisms for an evolutionary shift in function in the mollusk ortholog of the steroid hormone receptors (srs), a family of biologically essential transcription factors. in vertebrates, the activity of srs allosterically depends on binding a hormonal ligand ...201424415950
interlaboratory comparison of two aoac liquid chromatographic fluorescence detection methods for paralytic shellfish toxin analysis through characterization of an oyster reference material.an interlaboratory ring trial was designed and conducted by the centre for environment, fisheries, and aquaculture science to investigate a range of issues affecting the analysis of a candidate pacific oyster paralytic shellfish toxin reference material. a total of 21 laboratories participated in the study and supplied results using one or more of three instrumental methods, specifically precolumn oxidation (pre-cox) lc with fluorescence detection (fld; aoac official method 2005.06), postcolumn ...201424830149
effects of in vitro exposure to diarrheic toxin producer prorocentrum lima on gene expressions related to cell cycle regulation and immune response in crassostrea gigas.crassostrea gigas accumulates diarrheic shellfish toxins (dsp) associated to prorocentrum lima of which okadaic acid (oa) causes specific inhibitions of serine and threonine phosphatases 1 and 2a. its toxic effects have been extensively reported in bivalve mollusks at cellular and physiological levels, but genomic approaches have been scarcely studied.201424825133
[effects of calcification on respiratory quotient of cultured oyster crassostrea gigas and its fouling animals].respiratory quotient (rq) is one of the basic indices in physiology and energy metabolism of animals. when rq is calculated, the amount of released co2 is typically used directly. but for calcifying marine organisms, calcification which can affect dissolved inorganic carbon (dic) content in the water may cause methodological error to some extent, if it is ignored. in this paper, rq and o/n of cultured oyster crassostrea gigas and 3 marine fouling animal species (mytilus edulis, ciona intestinali ...201425223039
microplastics in bivalves cultured for human consumption.microplastics are present throughout the marine environment and ingestion of these plastic particles (<1 mm) has been demonstrated in a laboratory setting for a wide array of marine organisms. here, we investigate the presence of microplastics in two species of commercially grown bivalves: mytilus edulis and crassostrea gigas. microplastics were recovered from the soft tissues of both species. at time of human consumption, m. edulis contains on average 0.36 ± 0.07 particles g(-1) (wet weight), w ...201425005888
gametogenic cycle of crassostrea gigas in contrasting mediterranean habitats: marine (gulf of tunis) and continental (bizert lagoon) culture sites.the gametogenic cycle of crassostrea gigas, a species imported into the mediterranean for aquaculture, has been studied (may 2005 to july 2006) in two contrasting habitats of tunisia: the bizert lagoon, where oyster farms have been developed since 1970, and the gulf of tunis, where oysters have been experimentally farmed during this study, to assess the potential of this latter marine area for sustaining oyster-culture.201425984496
the nuclear receptor gene family in the pacific oyster, crassostrea gigas, contains a novel subfamily group.nuclear receptors are a superfamily of transcription factors important in key biological, developmental and reproductive processes. several of these receptors are ligand- activated and through their ability to bind endogenous and exogenous ligands, are potentially vulnerable to xenobiotics. molluscs are key ecological species in defining aquatic and terrestrial habitats and are sensitive to xenobiotic compounds in the environment. however, the understanding of nuclear receptor presence, function ...201424885009
molecular cloning and differential expression in tissues of a tyrosinase gene in the pacific oyster crassostrea gigas.tyrosinases are a group of type-3 copper proteins that catalyze the first two reactions in the melanin biosynthesis in organisms ranging from bacteria, fungi, plants to animals. tyrosinases are not only involved in pigmentation, but also play an important role in the innate immunity in invertebrates. additionally, tyrosinases are also known to be involved in the biogenesis and pigmentation of shells. the recently published crassostrea gigas genome sequences revealed that the pacific oyster posse ...201424859978
identification two novel nacrein-like proteins involved in the shell formation of the pacific oyster crassostrea gigas.nacrein-like proteins have carbonic anhydrase (ca)-like domains, but their coding regions are flanked by inserted repeat sequence, such as gly-x-asn. reportedly, nacrein-like proteins show the highest similarity to human carbonic anhydrase 1(α-ca1), possess ca catalytic functions, and play a key role in shell biomineralization. in the present study, two novel nacrein-like proteins were firstly identified from the shell-forming mantle of the pacific oyster crassostrea gigas. with numerous analyse ...201424584662
transcriptomic analysis of candidate osmoregulatory genes in the eastern oyster crassostrea virginica.the eastern oyster, crassostrea virginica, is a euryhaline species that can thrive across a wide range of salinities (5-35). as with all estuarine species, individual oysters must be able to regulate their osmotic balance in response to constant temporal variation in salinity. at the population level, recurrent viability selection may be an additional mechanism shaping adaptive osmoregulatory phenotypes at the margins of oyster salinity tolerance. to identify candidate genes for osmoregulation, ...201424950855
positive feedback loop between introductions of non-native marine species and cultivation of oysters in europe.with globalization, agriculture and aquaculture activities are increasingly affected by diseases that are spread through movement of crops and stock. such movements are also associated with the introduction of non-native species via hitchhiking individual organisms. the oyster industry, one of the most important forms of marine aquaculture, embodies these issues. in europe disease outbreaks affecting cultivated populations of the naturalized oyster crassostrea gigas caused a major disruption of ...201425047099
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