| effects of acclimation temperature and cadmium exposure on cellular energy budgets in the marine mollusk crassostrea virginica: linking cellular and mitochondrial responses. | in order to understand the role of metabolic regulation in environmental stress tolerance, a comprehensive analysis of demand-side effects (i.e. changes in energy demands for basal maintenance) and supply-side effects (i.e. metabolic capacity to provide atp to cover the energy demand) of environmental stressors is required. we have studied the effects of temperature (12, 20 and 28 degrees c) and exposure to a trace metal, cadmium (50 microg l(-1)), on the cellular energy budget of a model marine ... | 2006 | 16547299 |
| isolation by distance in the eastern oyster, crassostrea virginica, in chesapeake bay. | intensive efforts are underway to restore depleted stocks of crassostrea virginica in chesapeake bay. however, the extent of gene flow among local populations, an important force mediating the success of these endeavors, is poorly understood. spatial and temporal population structures were examined in c. virginica from chesapeake bay using eight microsatellite loci. deficits in heterozygosity relative to hardy-weinberg expectations were seen at all loci and were best explained by null alleles. p ... | 2008 | 16489144 |
| growth and survival of the american oyster crassostrea virginica in jamaica bay, new york. | jamaica bay is a major inlet opening to the atlantic ocean. it was abundant with oysters until early 1900's. over-harvesting, pressure from predators, parasitic invasion and declining water quality often are cited as causes. despite actions to arrest and reverse the pollution, oysters are not reestablished. we are studying factors relating to the rehabitation of crassostrea virginica in jamaica bay to determine if the water quality and environmental conditions are suitable for their survival. oy ... | 2005 | 26862590 |
| tissue-specific accumulation of cadmium in subcellular compartments of eastern oysters crassostrea virginica gmelin (bivalvia: ostreidae). | cadmium distribution was studied in different subcellular fractions of gill and hepatopancreas tissues of eastern oysters crassostrea virginica. oysters were exposed for up to 21 days to low sublethal cd concentrations (25 microg l(-1)). gill and hepatopancreas tissues were sampled and divided into organelle fractions and cytosol by differential centrifugation. organelle content of different fractions was verified by activities of marker enzymes, citrate synthase and acid phosphatase for mitocho ... | 2005 | 15993495 |
| sulfatase activity in the oyster crassostrea virginica: its potential interference with sulfotransferase determination. | two sulfatase isoforms, a soluble one with an optimum ph of 5.0, and a microsomal one with an optimum ph of 7.6, were observed in digestive gland, gonads, mantle and gills of the oyster c. virginica. the highest sulfatase activity was recorded in the digestive gland cytosol and is likely to interfere with the in vitro determination of sulfotransferase activity. indeed, the sulfatase inhibitor na(2)so(3) led to an increase of measured sulfotransferase activity (31+/-9%), suggesting that those sul ... | 2005 | 15963577 |
| cadmium exposure affects mitochondrial bioenergetics and gene expression of key mitochondrial proteins in the eastern oyster crassostrea virginica gmelin (bivalvia: ostreidae). | cadmium is a ubiquitous and extremely toxic metal, which strongly affects mitochondrial function of aquatic organisms in vitro; however, nothing is known about the in vivo effects of sublethal concentrations of this metal on mitochondrial bioenergetics. we have studied the effects of exposure to 0 (control) or 25 microg l-1 (cd-exposed) cd2+ on mitochondrial function and gene expression of key mitochondrial proteins in the eastern oyster crassostrea virginica. cadmium exposure in vivo resulted i ... | 2005 | 15935864 |
| the development of a physiologically-based pharmacokinetic model using the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the tissues of the eastern oyster (crassostrea virginica). | a physiologically-based pharmacokinetic model (pbpk) was developed to describe the kinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) in the eastern oyster (crassostrea virginica). the estimated t(1/2) of elimination for a bolus dose of tcdd in c. virginica is approximately 14-24 days based on both the experimental data and the pbpk model. the highest dioxin concentration reached during 28-days was in the digestive gland followed by the mantle, gonad, hemolymph, gill, adductor muscle, and th ... | 2005 | 15757746 |
| genetic analysis of selected strains of eastern oyster (crassostrea virginica gmelin) using aflp and microsatellite markers. | amplified fragment length polymorphisms (aflps) and microsatellite markers were used to examine genetic variation and divergence in 4 selected strains (dbh, neh, fmf, and cts) and 1 wild population (dbw) of the eastern oyster crassostrea virginica gmelin. eighty-six aflp markers (from 3 primer pairs) and 5 microsatellite loci were used for the analysis of 30 oysters from each of the 5 populations. microsatellite loci were considerably more variable than aflps. the observed heterozygosity ranged ... | 2008 | 15747088 |
| effect of multiple atrazine exposure profiles on hemocyte dna integrity in the eastern oyster (crassostrea virginica). | | 2004 | 15386059 |
| destabilized lysosomes and elimination of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in eastern oysters (crassostrea virginica). | contaminated oysters from near the galveston bay ship channel ([gbsc], tx, usa) were transplanted into clean aquariums in order to investigate the recovery of their lysosomal health. destabilized lysosomes in the oyster hemocytes recovered from 81% to 34% after 23 d of elimination. chemical analyses showed that transplanted oysters eliminated organic chemicals they had accumulated in their tissue. enhanced lysosomal health (i.e., decreased lysosomal destabilization) was correlated positively wit ... | 2004 | 15352489 |
| the effects of the contemporary-use insecticide (fipronil) in an estuarine mesocosm. | to examine the effects of environmentally realistic fipronil concentrations on estuarine ecosystems, replicated mesocosms containing intact marsh plots and seawater were exposed to three treatments of fipronil (150, 355, and 5000 ng/l) and a control. juvenile fish (cyprinidon variegatus), juvenile clams (mercenaria mercenaria), oysters (crassostrea virginica), and grass shrimp (palaemonetes pugio) were added prior to fipronil in an effort to quantify survival, growth, and the persistence of toxi ... | 2004 | 15261399 |
| microsatellite marker development and analysis in the eastern oyster (crassostrea virginica): confirmation of null alleles and non-mendelian segregation ratios. | eighteen microsatellite markers were developed for the crassostrea virginica nuclear genome, including di-, tri-, and tetranucleotide microsatellite repeat regions that included perfect, imperfect, and compound repeat sequences. a reference panel with dna from the parents and four progeny of 10 full-sib families was used for a preliminary confirmation of polymorphism at these loci and indications of null alleles. null alleles were discovered at three loci; in two instances, primer redesign enabl ... | 2006 | 15247315 |
| cadmium effects on mitochondrial function are enhanced by elevated temperatures in a marine poikilotherm, crassostrea virginica gmelin (bivalvia: ostreidae). | marine intertidal mollusks, such as oysters, are exposed to multiple stressors in estuaries, including varying environmental temperature and levels of trace metals, which may interactively affect their physiology. in order to understand the combined effects of cadmium and elevated temperature on mitochondrial bioenergetics of marine mollusks, respiration rates and mitochondrial volume changes were studied in response to different cadmium levels (0-1000 micromol l(-1)) and temperatures (15, 25 an ... | 2004 | 15201296 |
| esterification of vertebrate-like steroids in the eastern oyster (crassostrea virginica). | the esterification of two model vertebrate steroid hormones - estradiol (e2) and dehidroepiandrosterone (dhea) - was studied in the oyster crassostrea virginica. the activity of acyl-coa:steroid acyltransferase was characterized in microsomal fractions isolated from oyster digestive glands. the apparent km and vmax values changed with the fatty acid acyl-coa used (c20:4, c18:2, c18:1, c16:1, c18:0 or c16:0), and were in the range of 9-17 microm, and 35-74 pmol/min/mg protein for e2, and in the r ... | 2016 | 15178069 |
| linkages between cellular biomarker responses and reproductive success in oysters--crassostrea virginica. | the purpose of these studies was to evaluate if there were relationships between lysosomal destabilization or glutathione concentrations and gamete viability of oysters, crassostrea virginica. oysters were collected from field sites during the peak spawning period (may-june) during 2001 and 2002. lysosomal destabilization rates and glutathione concentrations of hepatopancreas tissues (e.g. digestive gland) were determined. eggs and sperm from the same adults were also used to conduct embryo deve ... | 2013 | 15178027 |
| diversity of metallothioneins in the american oyster, crassostrea virginica, revealed by transcriptomic and proteomic approaches. | metallothioneins are typically low relative molecular mass (6000-7000), sulfhydryl-rich metal-binding proteins with characteristic repeating cysteine motifs (cys-x-cys or cys-x(n)-cys) and a prolate ellipsoid shape containing single alpha- and beta-domains. while functionally diverse, they play important roles in the homeostasis, detoxification and stress response of metals. the originally reported metallothionein of the american oyster, crassostrea virginica showed the canonical molluscan alpha ... | 2004 | 15096209 |
| lc/ms analysis of brevetoxin metabolites in the eastern oyster (crassostrea virginica). | brevetoxin (pbtx) metabolism was examined in the eastern oyster (crassostrea virginica) following exposure to a karenia brevis red tide, by using lc/ms(/ms) and cytotoxicity assay. metabolites observed in field-exposed oysters were confirmed in oysters exposed to k. brevis cultures in the laboratory. previously, we identified a cysteine conjugate and its sulfoxide (mh(+): m/z 1018 and 1034) as metabolites of the brevetoxin congener pbtx-2. in the present study, we found a cysteine conjugate and ... | 2004 | 15051410 |
| esterification of vertebrate-type steroids in the eastern oyster (crassostrea virginica). | characteristics of acyl-coenzyme a (acyl-coa):steroid acyltransferase from the digestive gland of the oyster crassostrea virginica were determined by using estradiol (e2) and dehydroepiandrosterone (dhea) as substrates. the apparent km and vmax values for esterification of e2 with the six fatty acid acyl-coas tested (c20:4, c18:2, c18:1, c16:1, c18:0, and c16:0) were in the range of 9-17 microm e2 and 35-74 pmol/min/mg protein, respectively. kinetic parameters for esterification of dhea (km: 45- ... | 2004 | 15013691 |
| transfection of eastern oyster ( crassotrea virginica) embryos. | there is a need for research in disease resistance and microbial elimination in the eastern oyster crassosostrea virginica. gene transfer may lead to advances in this area, and a means of selecting transfected larvae would be useful. we transfected 3-hour-postfertilization embryos with the bacterial gene aminoglycoside phosphotransferase ii (neo(r)), which confers resistance to neomycin and related antibiotics such as g418. the antibiotic g418 was examined as a potential selective agent. a neutr ... | 2001 | 14961348 |
| potential indicators of stress response identified by expressed sequence tag analysis of hemocytes and embryos from the american oyster, crassostrea virginica. | a pilot program was initiated to identify genes from the american oyster, crassostrea virginica, that are potentially involved in the stress response for use as bioindicators of exposure to environmental pollutants and to toxic and infectious agents. a pcr-based method was used to construct cdna libraries from pooled embryos and the hemocytes of a single individual. a total of 998 randomly selected clones (expressed sequence tags, ests) were sequenced. approximately 40% of the ests are novel seq ... | 2002 | 14961291 |
| detection of oxidative dna damage in isolated marine bivalve hemocytes using the comet assay and formamidopyrimidine glycosylase (fpg). | organisms in polluted areas can be exposed to complex mixtures of chemicals; however, exposure to genotoxic contaminants can be particularly devastating. dna damage can lead to necrosis, apoptosis, or heritable mutations, and therefore has the potential to impact populations as well as individuals. single cell gel electrophoresis (the comet assay) is a simple and sensitive technique used to examine dna damage in single cells. the lesion-specific dna repair enzyme formamidopyrimidine glycoslyase ... | 2003 | 14644349 |
| uptake and depuration of toxic halogenated aromatic hydrocarbons by the american oyster (crassostrea virginica): a field study. | uptake and depuration of toxic chlorinated compounds such as planar polychlorinated biphenyls (pcbs 77, 126, 169), 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) and 2,3,7,8-tetrachlorodibenzofuran (tcdf) were monitored during a 50-day field study where american oysters (crassostrea virginica) were transplanted back and forth between a heavily polluted area (houston ship channel, sc) and a relatively unimpacted area (hanna's reef, hr) within galveston bay, tx. in general, low molecular weight, less ... | 2004 | 14559258 |
| relationship between pcb accumulation and reproductive output in conditioned oysters crassostrea virginica fed a contaminated algal diet. | because of their resistance to environmental degradation, polychlorinated biphenyls (pcbs) are among the most widespread environmental contaminants. pcbs have high bioaccumulation potential and may affect a number of biological/physiological processes including disruption of the endocrine system function, lipid metabolism and reproduction. the objective of this study was to test whether conditioning sexually immature oysters with pcb-contaminated algal diets affects their subsequent reproductive ... | 2003 | 13678848 |
| stimulation of defense factors for oysters deployed to contaminated sites in pensacola bay, florida. | a positive association between chemical contaminants and defense factors has been established for eastern oysters (crassostrea virginica) from florida, but it is unknown whether such factors can be stimulated through short-term exposure to contaminants in the field. hatchery oysters were deployed at two contaminated sites and one reference site near pensacola, florida, during spring and summer in 1998. putative defense measurements, notably hemocyte count and bactericidal activity, were signific ... | 2003 | 12878409 |
| greater hemocyte bactericidal activity in oysters (crassostrea virginica) from a relatively contaminated site in pensacola bay, florida. | bivalve mollusks such as crassostrea virginica inhabiting polluted estuaries and coastal areas may bioaccumulate high concentrations of contaminants without apparent ill effects. however, changes in putative internal defense activities have been associated with contaminant accumulation in both experimental and long-term field exposures. in an effort to elucidate these relationships, 40 oysters were collected from bayou chico (bc) and east bay (eb) in pensacola bay, fl, two estuaries known to dif ... | 2003 | 12878408 |
| genetic linkage map of the eastern oyster crassostrea virginica gmelin. | amplified fragment length polymorphisms (aflps), along with some microsatellite and type i markers, were used for linkage analysis in crassostrea virginica gmelin, the eastern oyster. seventeen aflp primer combinations were selected for linkage analysis with two parents and their 81 progeny. the 17 primer combinations produced 396 polymorphic markers, and 282 of them were segregating in the two parents. chi-square analysis indicated that 259 (91.8%) markers segregated in mendelian ratio, while t ... | 2003 | 12807709 |
| di- and tribromoindoles in the common oyster (crassostrea virginica). | the sources/origins, fate and impacts of naturally occurring organobromine compounds in the marine environment are largely unknown. soft tissue composites of the common oyster (crassostrea virginica) collected from coastal georgia (usa) were analyzed for organobromines by gas chromatography. three simple bromoindoles (bis)--two dibromo- and one tribromo congener--were detected and their molecular formulas elucidated by electron and negative chemical ionization gc-ms. semi-quantitative estimates ... | 2003 | 12738263 |
| pearl, a novel family of putative transposable elements in bivalve mollusks. | while genome sequencing projects have discovered numerous types of transposable elements in diverse eukaryotes, there are many taxa of ecological and evolutionary significance that have received little attention, such as the molluscan class bivalvia. examination of a 0.7-mb genomic sequence database from the cupped oyster crassostrea virginica revealed the presence of a common interspersed element, cva. cva possesses subterminal inverted repeats, a tandemly repeated core element, a tetranucleoti ... | 2003 | 12612834 |
| ovacystis-like condition in the eastern oyster crassostrea virginica from the northeastern gulf of mexico. | histological examination of the eastern oyster crassostrea virginica from a study in pensacola bay, florida, revealed 2 cases of abnormally large, basophilic ova that resembled cells characteristic of ovacystis disease previously reported in oysters from maine and long island. the hypertrophied gametes measured up to 250 pm in diameter, had scant cytoplasm and contained granular nuclear-masses of feulgen-positive material. electron microscopy of reclaimed tissue revealed these masses to consist ... | 2003 | 12608573 |
| the bioconcentration and metabolism of chlorpyrifos by the eastern oyster, crassostrea virginica. | eastern oysters (crassostrea virginica) were exposed to [14c]chlorpyrifos (o,o-diethyl-o-[3,5,6-trichloro-2-pyridyl] phosphorothioate) at an average measured seawater concentration of 0.6 microg/l under flow-through conditions for 28 d. the compound o,o-diethyl-o-(3,5-dichloro-6-methylthio-2-pyridyl)phosphorothioate (dmp) was extracted and identified as the single metabolite observed, and this metabolite constituted the majority of the total [14c] activity in the oyster at all sampling times. on ... | 2003 | 12558158 |
| seasonal variation in lysosomal destabilization in oysters, crassostrea virginica. | lysosomal destabilization assays have been used as valuable biomarkers of pollutant exposures in a variety of bivalve and fish species. the responses of oysters, crassostrea virginica, deployed at and native to various reference and degraded sites were evaluated for lysosomal destabilization during both summer and winter seasons. in both native and deployed oysters, lysosomal destabilization rates tended to be higher during the winter at both reference and polluted sites. there are at least two ... | 2006 | 12408652 |
| flow cytometric comparison of haemocytes from three species of bivalve molluscs. | haemocyte subpopulations from three bivalve species (the clams ruditapes philippinarum and mercenaria mercenaria and the oyster, crassostrea virginica) were characterised using light-scatter flow cytometry and a standard set of methods. two parameter (forward and side scatter) plots for the three species were very similar and resembled plots for mammalian white blood cells. two haemocyte groups (granulocytes and agranulocytes) were found in both the haemolymph and the extrapallial fluid of the c ... | 2002 | 12400864 |
| heat-shock protein (hsp70) response in the eastern oyster, crassostrea virginica, exposed to pahs sorbed to suspended artificial clay particles and to suspended field contaminated sediments. | sediments are a potentially significant source of pollutants, containing not only organic contaminants but heavy metals as well. the heat shock protein response (hsp70 family) in the eastern oyster exposed to suspended clay particles spiked with polynuclear aromatic hydrocarbons (pahs) and to suspended field contaminated sediments (sfcs) was investigated. in experiment 1, oysters were exposed to 1.0, 1.5 or 2.0 g suspended clay particles with concentrations of 65.6, 159.0 and 242 micro g pahs pe ... | 2002 | 12200083 |
| confirmation of brevetoxin metabolism in the eastern oyster (crassostrea virginica) by controlled exposures to pure toxins and to karenia brevis cultures. | previously, we analyzed eastern oysters (crassostrea virginica) naturally exposed to a karenia brevis red tide and found that brevetoxins (pbtx) are rapidly accumulated and metabolized. several metabolites were isolated and later identified, including a cysteine-pbtx conjugate (mh(+): m/z 1018) and its sulfoxide product (m/z 1034). in the present study, we confirm and extend those findings by examining pbtx metabolism and elimination in oysters exposed to pure toxins (pbtx-2 and -3) under contro ... | 2002 | 12175608 |
| metal partitioning between colloidal and dissolved phases and its relation with bioavailability to american oysters. | kinetics and the extent of metal partitioning between colloidal and dissolved phases and coagulation of metals associated with colloids were examined to determine their effects on the bioavailability of selected metals (cd, co, hg, ag, fe, and zn) to american oysters (crassostrea virginica) using radiotracer and short term exposure experiments. after dispersion of radiolabeled colloids into low molecular weight (lmw, < 1 kda) seawater, metal partitioning between dissolved (<1 kda) and colloidal ... | 2002 | 12148944 |
| relationship between lysosomal membrane destabilization and chemical body burden in eastern oysters (crassostrea virginica) from galveston bay, texas, usa. | lysosomal destabilization was measured by using hemocytes of eastern oysters (crassostrea virginica) collected along a chemical concentration gradient in galveston bay, texas, usa. results of the lysosomal response were compared to concentrations of organic compounds and trace elements in oyster tissue. concentrations (on a dry-wt basis) ranged from 288 to 2,390 ng/g for polycyclic aromatic hydrocarbons (pahs), 38 to 877 ng sn/g for tri-n-butyltin (tbt), 60 to 562 ng/g for polyclorinated bipheny ... | 2002 | 12069313 |
| shell disease in eastern oysters, crassostrea virginica, reared in france. | progeny of eastern oyster, crassostrea virginica, introduced into france in 1992, were reared in ifremer facilities to test their growth performances. during the summer of 1993, sporadic mass mortalities (80-90%) occurred among c. virginica spat reared in the ifremer laboratories in la tremblade (charente maritime, france) and bouin (vendée, france). affected oysters presented mantle retraction and deposition of an anomalous conchiolin layer on the inner surface of the shell. the incidence of oy ... | 2002 | 12054781 |
| matrix metalloproteinase-like activity from hemocytes of the eastern oyster, crassostrea virginica. | investigation of oyster blood cell lysate revealed one prominent band of proteolytic activity when analyzed using gelatin and collagen impregnated polyacrylamide gel electrophoresis. the proteolytic activity was inhibited by 1,10 phenanthroline and edta, but not by other proteinase inhibitors. maximal activity was shown at ph 8.2 and the molecular weight of the protein responsible for the activity was estimated to be 68 kda. proteolytic activity was also measured by fluorescence assays containin ... | 2002 | 11959018 |
| hydrocarbon effects on fouling assemblages: the importance of taxonomic differences, seasonal, and tidal variation. | effects of hydrocarbon-contaminated substrata on recruitment of three species of fouling organisms were studied along the louisiana gulf coast. clay tiles (232 cm2) were exposed to crude oil, 10% water soluble fraction of crude oil, or 25 g/kg artificial seawater, and placed out at two locations, in two seasons, and at two tidal levels in an estuary near port fourchon, louisiana. bryozoan (membranipora savartii) recruitment was significantly reduced in all experiments on crude oil-exposed tiles. ... | 2002 | 11939295 |
| perfluorooctane sulfonate in oysters, crassostrea virginica, from the gulf of mexico and the chesapeake bay, usa. | concentrations of perfluorooctane sulfonate (pfos), a metabolite of several sulfonated perfluoroorganic compounds, were measured in oysters collected from 77 locations in the gulf of mexico and chesapeake bay of the united states. pfos was detected in oysters collected from 51 of the 77 locations at concentrations ranging from < 42 to 1,225 ng/g on a dry weight basis. this study provides baseline data for future monitoring programs to examine long-term trends in concentrations of pfos. | 2002 | 11910459 |
| the status and trends of trace element and organic contaminants in oysters, crassostrea virginica, in the waters of the carolinas, usa. | concentrations of eight trace elements (as, cd, cu, hg, ni, pb, se and zn), lindane and six groups of organic contaminants (total-chlordane, total-pcb, total-ddt, dieldrin and aldrin, total-butyltins, total-pahs) at the 11 noaa mussel watch project (mwp) sites located in north and south carolina have been compared with the national us mwp data. three sites from north and south carolina had concentrations of pahs in the upper 15th percentile on a national scale. one site had high concentrations o ... | 2002 | 11874050 |
| epizootiology and pathology of juvenile oyster disease in the eastern oyster, crassostrea virginica. | juvenile oyster disease (jod) causes mortalities of small cultured oysters, crassostrea virginica. the present study was an intensive epizootiological and pathological investigation of jod in eight sequentially deployed cohorts at sites on long island, new york. jod symptoms and mortalities began in all groups at about the same time. lesions on the mantle were detected histologically about 1 week before the principal symptom, a conchiolin deposit on the inner shell, appeared. mortality began abo ... | 2001 | 11812117 |
| relationships between tissue contaminants and defense-related characteristics of oysters (crassostrea virginica) from five florida bays. | evidence linking bivalve defense responses with pollutant exposure is increasing. contaminant effects on immune or defense responses could influence the ability of an organism to resist infectious disease. this study explored relationships between xenobiotic chemicals accumulated in oyster (crassostrea virginica) tissue and various measures of putative oyster internal defense activities and physiological condition. defense-related and physiological measurements were made on individual oysters co ... | 2001 | 11595310 |
| expression of p-glycoprotein in the gills of oysters, crassostrea virginica: seasonal and pollutant related effects. | the expression of p-glycoprotein (p-gp) in aquatic organisms has been proposed as a biomarker of pollution exposure. previous research has provided evidence that p-gp is inducible by organic xenobiotics and that p-gp is overexpressed in mussels from degraded areas. however, seasonal changes in expression at polluted sites has not been described previously. the purposes of these studies were to evaluate the expression of p-gp in polluted and unpolluted sites in oysters (crassostrea virginica) and ... | 2001 | 11489306 |
| expression of p-glycoprotein in southeastern oysters, crassostrea virginica. | these studies provide important fundamental information regarding the expression of p-glycoprotein (p-gp) in southeastern oysters (crassostrea virginica). using rhodamine transport studies, p-gp activity was detected in newly fertilized embryos. a monoclonal antibody (c219) was used to evaluate p-gp expression in oyster tissues. on the basis of laboratory studies, p-gp expression tended to be higher in gill tissues than mantle tissues, and was generally not related to salinity differences. seaso ... | 2001 | 11488357 |
| the effect of pcbs on glycogen reserves in the eastern oyster crassostrea virginica. | recent declines in chesapeake bay oyster populations have been attributed to disease, and reduced water quality from pollution. the stress associated with pollutant exposure may reduce energy available for growth and reproduction. polychlorinated biphenyls (pcbs) are lipophilic contaminants that may potentially affect mobilization of lipid reserves, increasing reliance on glycogen stores, which could otherwise be utilized to supply energy for gametogenesis. thus, pcbs may indirectly affect glyco ... | 2013 | 11460732 |
| effects of pcbs sorbed to algal paste and sediments on the stress protein response (hsp70 family) in the eastern oyster, crassostrea virginica. | this study examined the stress protein response (hsp70 family) of reproductively inactive oysters fed 0.7 g algal paste containing 0, 0.35 and 3.5 micrograms polychlorinated biphenyls (pcbs) daily. a second set of treatment groups investigated the combined effect of pcbs and sediments (0.3 g sediments daily per oyster) on hsp70 response. after 8 weeks of pcb exposure, oyster tissues (mantle and gill) were sampled and analyzed for hsp70. preliminary results did not show a significant effect in hs ... | 2013 | 11460715 |
| pcb uptake and accumulation by oysters (crassostrea virginica) exposed via a contaminated algal diet. | reproductively active oysters were fed daily with 0.2 g algal paste containing 0, 0.1, and 1.0 microgram polychlorinated biphenyls (pcbs) (1:1:1 mixture of aroclor 1242, 1254 and 1260) for either 15 or 30 days, and accumulation of pcbs in different organ tissues and eggs assessed. the effects of pcb exposure on lipid content, lipid class and fatty acid composition were also evaluated. pcbs were accumulated by the oysters and transferred to the eggs. pcb accumulation in oysters was dose, time and ... | 2013 | 11460693 |
| the effects of glutathione depletion on reproductive success in oysters, crassostrea virginica. | glutathione (gsh) is a ubiquitous tripeptide that functions as a very important modulator of cellular homeostasis, including detoxification of metals and oxyradicals. therefore, depletion of gsh may predispose organisms to pollutant stress. reproductively active oysters (crassostrea virginica) were exposed to buthionine sulfoximine in the laboratory to deplete gonadal gsh. the effects of metal exposures (cd and cu) on fertilization and developmental assays were evaluated using gametes from contr ... | 2013 | 11460691 |
| quantitative reverse transcription polymerase chain reaction of a molluscan metallothionein mrna. | a quantitative assay based on competitive reverse transcription polymerase chain reaction (rt-pcr) was developed for metallothionein (mt) mrna of the mollusc crassostrea virginica and applied to analysis of mt mrna of hemocytes. the assay was based on titration of a competitive external standard crna derived from the coding region of the oyster mt mrna. serial dilutions of the crna standard were coamplified with a constant amount of total rna using biotinylated primers common to both target and ... | 2001 | 11451426 |
| laboratory investigations of the effects of predator sex and size on prey selection by the asian crab, hemigrapsus sanguineus. | laboratory studies have shown that the nonindigenous asian shore crab, hemigrapsus sanguineus, readily consumes three species of commercial bivalves: blue mussels, mytilus edulis, soft-shell clams, mya arenaria, and oysters, crassostrea virginica. although crabs can eat bivalves of a wide size range, they preferred the smaller prey (</=10 mm sl). prey critical size limits exist for m. edulis and c. virginica, but not m. arenaria, possibly because of differences in shell characteristics among the ... | 2001 | 11445087 |
| cryopreservation of heart cells from the eastern oyster. | conditions were developed to cryopreserve cells from pronase-dissociated atria and ventricles of eastern oysters (crassostrea virginica). the effect of three concentrations (5, 10, 15%) of the cryoprotectants (dimethyl sulfoxide, glycerol, and propylene glycol), three thawing temperatures (25, 45, 75 degrees c), and three cooling rates (slow, medium, fast) were compared. cells were frozen at -80 degrees c and plunged in liquid nitrogen. thawed cells were seeded in 96-well plates and primary cult ... | 2001 | 11409690 |
| effect of dissolved organic matter on the uptake of trace metals by american oysters. | to examine the effects of dissolved organic matter on metal bioavailability, uptake of trace metals (cd, co, hg, cr, ag, zn) by american oysters (crassostrea virginica) was compared between treatments with different dissolved organic carbon (doc) concentrations and contrasting low molecular weight (lmw, 1 kda) and high molecular weight (hmw, 1 kda-0.2 micron) doc fractions, using radiotracer techniques and short-term exposure experiments. uptake rate constants (ml g-1 h-1) of metals, in general, ... | 2001 | 11351531 |
| factors that influence the accumulation of copper and cadmium by transplanted eastern oysters (crassostrea virginica) in the patuxent river, maryland. | to investigate the continued accumulation of copper and cadmium by oysters in the patuxent river, md, which have been at high levels since at least the mid 1960s, hatchery-raised eastern oysters were transplanted into trays at four sites in the upper estuary. at each site two groups of oysters were used to determine growth and mortality, and another group was sampled for meat condition, metal concentration and body burden. copper in oysters in the discharge of a coal-fired power plant was signif ... | 2000 | 11285737 |
| characterization of microsatellite loci in the eastern oyster, crassostrea virginica. | | 2000 | 11221805 |
| characterization of microsatellite loci in the eastern oyster, crassostrea virginica. | | 2000 | 11188988 |
| characterization of microsatellite loci in the eastern oyster, crassostrea virginica | | 2000 | 11123661 |
| cloning and sequence analysis of a cdna for an inducible 70 kda heat shock protein (hsp70) of the american oyster (crassostrea virginica). | we have been investigating 70 kda heat shock proteins (hsp70s) as potential molecular markers for improved breeding and stress management to revitalize stocks of the american oyster, c. virginica. from a c. virginica visceral mass library, a 2.2 kb full-length cdna was isolated that included a 634 amino acid open reading frame possessing approximately 80% sequence identity with inducible and constitutive hsp70s of a broad array of animal species. northern blotting indicated that the cloned cdna ... | 2000 | 11092737 |
| a survey of oysters crassostrea virginica from tampa bay, florida: associations of internal defense measurements with contaminant burdens. | oysters from 16 sites in tampa bay, florida, were collected during a 6-week period in winter 1993 and analyzed for both biological characteristics and tissue chemical concentrations. using previous sediment contamination and toxicity data, oyster tissues from the selected sites were expected to exhibit a wide range in both quantity and type of chemicals. chemical analysis showed tissue concentrations at some of these sites to be greater than national averages, as reported by the national status ... | 2000 | 10998504 |
| effects of glutathione depletion on copper cytotoxicity in oysters (crassostrea virginica). | glutathione is a tripeptide that plays an important role in ameliorating metal toxicity. depletion of glutathione has been associated with an increased risk of metal toxicity in mammals. an understanding of the toxicological significance of glutathione depletion in oysters would be of considerable importance given the widespread use of bivalves in biological monitoring. laboratory studies were conducted by using an inhibitor of glutathione synthesis (buthionine sulfoximine) to investigate the ef ... | 2000 | 10967396 |
| seasonal change and prolonged anoxia affect the kinetic properties of phosphofructokinase and pyruvate kinase in oysters. | the effects of seasonal change, november versus july, and prolonged anoxia (96 h under n2 gas) on the properties of phosphofructokinase and pyruvate kinase from five tissues (gill, mantle, hepatopancreas, phasic adductor, catch adductor) of the oyster, crassostrea virginica were investigated. both enzymes showed tissue-specific and season-specific changes in kinetic properties; for pyruvate kinase this correlated with seasonal differences in enzyme elution patterns on hydroxylapatite chromatogra ... | 2000 | 10935519 |
| improved attachment and spreading in primary cell cultures of the eastern oyster, crassostrea virginica. | at present, establishment of a cell line from bivalve molluscs has been unsuccessful, and in vitro work is limited to primary cell cultures. we sought to improve attachment and spreading of cells of the eastern oyster, crassostrea virginica, to aid primary cultures and to assist development of a bivalve cell line. our objectives were to examine the effects of substrate on ventricle cell viability, attachment, and spreading by testing of collagen i, collagen iv, fibronectin, laminin, poly-d-lysin ... | 2006 | 10614868 |
| reactive oxygen intermediate production by oyster hemocytes exposed to hypoxia | oysters are frequently exposed to severely hypoxic conditions, especially during summer months. during the summer, there are also large numbers of disease-related oyster mortalities. this research was conducted to determine whether exposure to environmental hypoxia reduces the ability of oyster hemocytes to produce reactive oxygen intermediates (rois), an important part of their defense system. oysters of the species crassostrea virginica were held in normoxic (p(o)(2)=20.0-20.7 kpa, ph 7.8-8.0) ... | 1999 | 10539962 |
| 2-keto-3-deoxy-d-glycero-d-galacto-nononic acid (kdn)- and n-acetylneuraminic acid-cleaving sialidase (kdn-sialidase) and kdn-cleaving hydrolase (kdnase) from the hepatopancreas of oyster, crassostrea virginica. | kdn (2-keto-3-deoxy-d-glycero-d-galacto-nononic acid), a sialic acid analog, has been found to be widely distributed in nature. despite the structural similarity between kdn and neu5ac, alpha-ketosides of kdn are refractory to conventional sialidases. we found that the hepatopancreas of the oyster, crassostrea virginica, contains two kdn-cleaving sialidases but is devoid of conventional sialidase. the major sialidase, kdn-sialidase, effectively cleaves alpha-ketosidically linked kdn and also slo ... | 1999 | 10542227 |
| influences of subzero thermal acclimation on mitochondrial membrane composition of temperate zone marine bivalve mollusks. | the phospholipid and phospholipid fatty acid composition of gill mitochondrial membranes from two temperate zone marine bivalve mollusks, the quahog, mercenaria mercenaria, and the american oyster, crassostrea virginica, were examined after acclimation to 12 and -1 degree c. cardiolipin (cl) was the only phospholipid with proportions altered upon acclimation to -1 degree c, increasing 188% in the mitochondrial membranes of m. mercenaria. although the ratio of bilayer stabilizing to destabilizing ... | 1999 | 10188598 |
| acidification of the phagosome in crassostrea virginica hemocytes following engulfment of zymosan. | phagocytic hemocytes are responsible for engulfing and internally degrading foreign organisms within the hemolymph and tissue of the eastern oyster, crassostrea virginica. since rapid acidification of the phagosome lumen is typically essential for activation of hydrolytic and reactive oxygen intermediate (roi) producing enzymes in vertebrate cells, we measured phagosomal ph in oyster hemocytes by using the emission fluorescence of two fluorescent probes, rhodamine and oregon green 488 (og 488), ... | 1999 | 10065529 |
| the basis for increased metallothionein in a natural population of crassostrea virginica. | metallothionein (mt) is elevated in a natural population of the oyster crassostrea virginica that is exposed to cadmium. however, induction of mt is not a likely cause for this elevation. this was concluded after re-examination of the results of a study in which mt mrna and mt s were analysed in oysters collected from a cadmium-contaminated environment. mt mrna concentrations did not differ in oysters collected from a cadmium exposure gradient and could not account for increases in mt, although ... | 1999 | 23902391 |
| biomarker studies with juvenile oysters (crassostrea virginica) deployed in-situ. | hatchery-reared juvenile oysters (crassostrea virginica) were deployed in situ for approximately 1 month from mid-may to mid-june of 1996 at sites that were classified as reference, agricultural, suburban, or urban/industrial. cellular responses (lysosomal destabilization, glutathione concentrations, lipid peroxidation, heat shock proteins, metallothioneins, and multi-xenobiotic resistance proteins) were analysed, and their efficacy as biomarkers of stress was evaluated. increased lysosomal dest ... | 1999 | 23902386 |
| population structure in the american oyster as inferred by nuclear gene genealogies. | multiple haplotypes from each of three nuclear loci were isolated and sequenced from geographic populations of the american oyster, crassostrea virginica. in tests of alternative phylogeographic hypotheses for this species, nuclear gene genealogies constructed for these haplotypes were compared to one another, to a mitochondrial gene tree, and to patterns of allele frequency variation in nuclear restriction site polymorphisms (rflps) and allozymes. oyster populations from the atlantic versus the ... | 1998 | 9491610 |
| metallothionein mrna induction and generation of reactive oxygen species in molluscan hemocytes exposed to cadmium in vitro. | (1) hemocytes of the oyster crassostrea virginica were exposed to cd in vitro to examine the concomitant induction of metallothionein (mt) mrna and production of reactive oxygen species (ros) during the oxidative burst response of phagocytic cells. (2) mt mrna induction was concentration-dependent, exhibiting a threshold between 5 and 10 microm cdcl2, and an increase at higher cd concentrations up to a maximum level of 36 microm cdcl2. continued increases in the cd exposure concentrations result ... | 1997 | 9490185 |
| detection of apgwamide-like immunoreactivity in the sea scallop, placopecten magellanicus. | in pulmonate gastropods, the peptide, ala-pro-gly-trp-nh2 (apgwamide), appears to be located nearly exclusively in the neural circuitry controlling the male reproductive organs. this neuropeptide and related neuropeptides are also present and apparently bioactive in bivalve molluscs, although their physiological role in these latter animals is unknown. the present report uses immunohistochemistry to examine the distribution of apgwamide and/or related peptides within the tissues of the deep sea ... | 1997 | 9179869 |
| effect of in vitro exposure to tributyltin on generation of oxygen metabolites by oyster hemocytes. | mollusks depend chiefly on hemocyte-mediated cytotoxic mechanisms such as reactive oxygen species (ros) to defend against pathogenic microorganisms. the effect of in vitro tributyltin chloride (tbt) exposure on ros generation by oyster (crassostrea virginica) blood phagocytes is quantified in this study. luminol-augmented chemiluminescence (lcl) was used to measure ros activity of resting and zymosan-stimulated cells after 1 or 20 hr tbt exposure. lcl is thought to measure primarily the activity ... | 1997 | 9339219 |
| a 1h nmr investigation of the hydrolysis of a synthetic substrate by kdn-sialidase from crassostrea virginica. | the mechanism of hydrolysis of 4-methylumbelliferyl 3-deoxy-d-glycero-alpha-d-galacto-2-nonulopyranosidonic acid (kdn alpha 2meumb, 4) by kdn-sialidase isolated from the hepatopancreas of the oyster crassostrea virginica has been monitored by 1h nmr spectroscopy. the results of these experiments reveal that kdn-sialidase catalyses the hydrolysis of the synthetic substrate kdn alpha 2meumb, with initial release of alpha-d-kdn. this is consistent with an overall mechanism for the hydrolysis which ... | 1996 | 8981083 |
| detection of dsp-toxins, okadaic acid, and dinophysis toxin-1 in shellfish by serine/threonine protein phosphatase assay. | a relatively rapid protein phosphatase-based assay was developed for detecting okadaic acid in extracts of shellfish, using oysters (crassostrea virginica) as a model. the assay has good sensitivity, detecting okadaic acid in crude methanolic extracts of oysters at > or = 4 ng/ml (> or = 0.1 ng/assay). assay accuracy for detecting toxic shellfish was validated through a series of spike recovery experiments. in more than 320 assessments, all oysters containing toxic amounts of okadaic acid (> or ... | 2013 | 8946712 |
| cadmium-induced metallothionein expression during embryonic and early larval development of the mollusc crassostrea virginica. | newly fertilized eggs of the oyster crassostrea virginica were exposed to 0.2 microm cd and sampled during the first 24 hr of embryonic and larval development for determination of the temporal patterns of total bioaccumulated and metallothionein (mt)-bound cd concentrations and the concentrations of mt mrna. in comparison with controls, exposure to this concentration of cd resulted in delayed development to the d-stage veliger larval stage. maternal mt mrna, which was carried over into the egg, ... | 1996 | 8887452 |
| lack of geographic variation in anonymous nuclear polymorphisms in the american oyster, crassostrea virginica. | comparing geographic variation of noncoding nuclear dna polymorphisms, which presumably are neutral to natural selection, with geographic variation of allozymes is potentially a good way to detect the effects of selection on allozyme polymorphisms. a previous study of four anonymous nuclear markers in the american oyster, crassostrea virginica, found dramatic differences in allele frequency between the gulf of mexico and the atlantic ocean. in contrast, 14 allozyme polymorphisms were fairly unif ... | 1996 | 8865664 |
| wood preservative leachates from docks in an estuarine environment. | environmental concentrations and biological effects of certain metals and organic compounds found in wood preservatives were examined. the study focused on leachates from private residential docks in south carolina tidal creeks. copper, chromium, arsenic, and polynuclear aromatic hydrocarbons (pahs) were measured in composite samples of surficial sediments and naturally occurring oyster populations (crassostrea virginica) from creeks with high densities of docks, and from nearby reference creeks ... | 1996 | 8687987 |
| genetics of scndna polymorphisms in juvenile oysters (crassostrea virginica). part i: characterizing the inheritance of polymorphisms in controlled crosses. | the amplification of dna by polymerase chain reaction followed by restriction enzyme digestion was used to examine five anonymous single-copy nuclear dna polymorphisms in 11 pair crosses for juvenile oysters (crassostrea virginica). there was an overall 7% frequency of aberrant (non-mendelian) offspring genotypes among 174 total pair-cross progeny. strict mendelian inheritance of alleles was observed for two of the five loci. possible explanations for the aberrant offspring genotypes include non ... | 1996 | 8680525 |
| seasonal responses of the mixed-function oxygenase system in the american oyster, crassostrea virginica (gmelin 1791), to urban-derived polycyclic aromatic hydrocarbons. | mixed-function oxygenase (mfo) system components (cytochrome p450 and b5, "423 peak" and nadph cytochrome c reductase) and body burdens of polycyclic aromatic hydrocarbons (pahs) were determined seasonally in oysters, crassostrea virginica (gmelin 1791), collected from an undeveloped estuary (north inlet, sc) and an urbanized estuary (murrells inlet, sc). all mfo system components monitored in oysters from north inlet demonstrated seasonal variations; levels were lowest during october 1992. whol ... | 1995 | 8838682 |
| cadmium-induced expression of metallothionein and suppression of rna to dna ratios during molluscan development. | one-week-old larvae of the mollusc crassostrea virginica, an oyster, were exposed to cd concentrations ranging from the control with no added cd to 0.2 microm cdcl2 for 24 hr. concentration-dependent increases in total cadmium accumulation, cytosolic and metallothionein-bound cd concentrations, and levels of the mt mrna were detectable over this range of exposure concentrations. increases in these measures were apparent at the lowest exposure concentration of 0.005 microm, with dramatic increase ... | 1995 | 7541169 |
| a divergent cdna homologue of the c-myc proto-oncogene in the eastern oyster crassostrea virginica: implications for myc evolution. | the polymerase chain reaction was used to identify myc-like cdna fragments from several marine invertebrate phyla. a pcr clone produced from the eastern oyster crassostrea virginica was subsequently used to screen a larval cdna library, and a 1.9-kb cdna clone was isolated and sequenced. the putative amino acid sequence encoded by this clone evidences a leucine zipper at its predicted carboxyl-terminus and has an overall structural similarity to vertebrate c-myc proto-oncogenes with several regi ... | 1995 | 7773336 |
| distribution of polycyclic aromatic hydrocarbons in oyster (crassostrea virginica) and surface sediment from two estuaries in south carolina. | the concentration of polycyclic aromatic hydrocarbons (pahs) was determined in oysters and sediments collected from two high salinity estuaries from the coast of south carolina. the two estuaries were murrells inlet (urban), an estuary receiving urbanized drainage and run-off, and north inlet (non-urban), receiving drainage from heavily forested terrain and minimal anthropogenic input. a minimum of thirty (30 stations were sampled in murrells and north inlets, respectively. a composite oyster sa ... | 1995 | 7755394 |
| metallothionein induction as a measure of response to metal exposure in aquatic animals. | metallothioneins (mts) are considered central in the intracellular regulation of metals such as copper, zinc, and cadmium. increased mt synthesis is associated with increased capacity for binding these metals and protection against metal toxicity. recent advances in the biochemistry and molecular biology of mts have facilitated research on mts in aquatic species. for the bivalve mollusc crassostrea virginica, a species frequently used in studies on the toxicology and environmental monitoring of ... | 1994 | 7713043 |
| hemocyte-derived reactive oxygen intermediate production in four bivalve mollusks. | luminol-dependent chemiluminescence (ldcl) and nitroblue tetrazolium (nbt) reduction assays have been used to measure reactive oxygen intermediate (roi) production by oyster (crassostrea virginica) hemocytes, as well as roi modulation caused by disease or exposure to environmental toxicants. however, roi responses measured by these tests apparently vary considerably among other bivalve species. in all species tested, unstimulated hemocytes produced small quantities of rois. in c. virginica and g ... | 2011 | 8082818 |
| disseminated neoplastic cells in mytilus trossulus: verification of host species origin by (16s-like) rrna sequence comparison. | disseminated neoplasia is a leukemia-like disease that occurs in many species of bivalve molluscs worldwide, including the bay mussel (mytilus trossulus). the etiology of the disease is undetermined, but an early report proposed that the anomalous bivalve cells were actually an invasive parasite rather than cancerous cells of host origin. comparison of partial sequences of small subunit rrna from normal and putative cancer cells was performed to resolve this issue. these studies showed a close p ... | 1994 | 8055063 |
| field studies using the oyster crassostrea virginica to determine mercury accumulation and depuration rates. | | 1993 | 8219605 |
| cytology and biochemistry of brown cells in crassostrea virginica collected at clean and contaminated stations. | this study examined brown cells of oysters, crassostrea virginica, as potential indicators of pollution related stress. regardless of collection station brown cells increased in connective tissue when it was inflamed. significantly (alpha < 0.05) fewer brown cells were observed in connective tissue of oysters from the clean versus the contaminated station; no significant differences in size were apparent in brown cells or vesicles between the two stations. brown cell vesicles in connective tissu ... | 1993 | 15091904 |
| weight and salinity effects on zinc uptake and accumulation for the american oyster (crassostrea virginica gmelin). | the power relationships of short-term net uptake and of in-situ body burden with body weight were examined. the accumulation of soft tissue zinc in the american oyster (crassostrea virginica) was related to time integration of uptake. short term uptake of (65)zn was measured in the laboratory. it was (i) a function of the (dry soft-tissue) weight of the oyster, (ii) inversely related to the salinity of the ambient water, and (iii) increased linearly with ambient concentrations. when in-situ soft ... | 1993 | 15091788 |
| matrix solid-phase dispersion extraction and gas chromatographic screening of 14 chlorinated pesticides in oysters (crassostrea virginica). | a multiresidue isolation technique known as matrix solid-phase dispersion (mspd) is presented for the extraction and subsequent gas chromatographic/electron capture detection (gc/ecd) determination of 14 chlorinated pesticides (alpha-bhc, beta-bhc, lindane, heptachlor, aldrin, heptachlor epoxide, p,p'-dde, dieldrin, endrin, 4,4'-ddd, endrin aldehyde, p,p'-ddt, endosulfan sulfate, and methoxychlor) from oysters (crassostrea virginica). pureed whole oysters (0.5 g aliquots) are fortified with the ... | 2009 | 8448447 |
| immunohistochemical localization and radioenzymatic measurements of serotonin (5-hydroxytryptamine) in hearts of aplysia and several bivalve mollusks. | serotonin immunoreactivity was localized in hearts of the opisthobranch gastropod, aplysia californica (sea hare) and several species of bivalve mollusks, the heterodonts, mercenaria mercenaria (quahog or cherry stone clam), protothaca staminea (little neck clam), and the pteriomorphs, hinnites multirugosus (rock scallop), crassostrea virginica (eastern oyster), mytilus edulis (eastern mussel), and geukensia demissa (ribbed mussel). in addition, serotonin was assayed in the ventricles, auricles ... | 1992 | 1423510 |
| small subunit rrna gene sequence of crassostrea virginica (gmelin) and a comparison with similar sequences from other bivalve molluscs. | | 1991 | 1945889 |
| morphology and mobility of oyster hemocytes: evidence for seasonal variations. | hemocytes of crassostrea virginica were video recorded and tracked to determine their locomotive rates and to assign these rates to wright-stained morphological variants. from 24 oysters examined in january, february, march, and may, 1571 hemocytes were video recorded, identified, and their rate of locomotion (rol) measured. granulocytes (three types) and agranulocytes (one lymphoid and three nonlymphoid types) were recognized. focusing on 15 oysters in march and may, 20,318 hemocytes were count ... | 1991 | 1783778 |
| primary structure of molluscan metallothioneins deduced from pcr-amplified cdna and mass spectrometry of purified proteins. | the primary structure of metallothioneins (mt) of a mollusc, the oyster crassostrea virginica, was determined by molecular cloning and mass spectrometry of purified proteins. the cloning strategy included pcr amplification of the responsible cdnas from total cdna using completely degenerate oligonucleotides (derived from the n-terminal amino acid sequence) and oligo(dt)20 as primers. primer extension off mrna was used as an independent determination of the nucleotide sequence represented by the ... | 1991 | 1888750 |
| structure and time-dependent behavior of acetylated and non-acetylated forms of a molluscan metallothionein. | cadmium-induced metallothionein in a mollusc, the oyster crassostrea virginica, occurs in both blocked and unblocked forms (roesijadi, g., kielland, s.l. and klerks, p. (1989) arch. biochem. biophys. 273, 403-413). the block, which is the sole difference in the structure of the two proteins, was identified as an acetyl group with use of tandem mass spectrometry. the blocked and unblocked proteins carried n-acetylserine and serine, respectively, at the n-terminus and were designated cvnacmt and c ... | 1991 | 2065077 |
| carcinogenicity of black rock harbor sediment to the eastern oyster and trophic transfer of black rock harbor carcinogens from the blue mussel to the winter flounder. | the eastern oyster (crassostrea virginica) developed neoplastic disorders when experimentally exposed both in the laboratory and field to chemically contaminated sediment from black rock harbor (brh), bridgeport, connecticut. neoplasia was observed in oysters after 30 and 60 days of continuous exposure in a laboratory flow-through system to a 20 mg/l suspension of brh sediment plus postexposure periods of 0, 30, or 60 days. composite tumor incidence was 13.6% (49 neoplasms in 40, n = 295) for bo ... | 1991 | 2050083 |
| silver uptake and subsequent effects on growth and species composition in an estuarine community. | silver within chesapeake bay is rapidly taken up by phytoplankton, in accordance with geochemical controls over silver speciation. phytoplankton accumulate large cellular burdens at non-lethal concentrations, setting up the potential for transfer of silver to herbivores that graze upon the phytoplankton community. however, the american oyster, crassostrea virginica, does not assimilate silver from phytoplankton, but rather from that dissolved in water. oysters can accumulate high burdens of silv ... | 1990 | 2084845 |
| trace metals in gulf of mexico oysters. | oysters (crassostrea virginica) from 50 to 69 locations (sites) along the gulf of mexico coastline, collected annually in 1986, 1987 and 1988, have been analyzed for 13 trace metals, including most of the metals of concern from an environmental quality perspective. essentially the entire u.s. gulf coastline was sampled, from far south texas to far south florida. pooled samples of 20 oysters from three different stations at each site were analyzed by atomic absorption spectrophotometry. the conce ... | 1990 | 2084839 |
| heavy metals in the eastern oyster, crassostrea virginica, of the mississippi sound. | | 1990 | 2306531 |
| a study of steady state and kinetic regulation of chloride ion and osmotic pressure in hemolymph of oysters, crassostrea virginica, exposed to tri-n-butyltin. | two sets of experiments were made to determine if bis(tri-n-butyl)tin oxide (tbt) [iupac: hexabutyldistannoxane] influenced osmotic pressure or chloride ion concentration in hemolymph of adult american oysters, crassostrea virginica. in the first set, oysters were acclimated to 5, 25 or 40%;, then exposed to bis(tri-n-butyl)tin oxide dissolved in seawater (0.5, 1.0 or 2.0 micrograms/l) for 11 days. measurements of the total osmotic pressure and chloride ion concentration in hemolymph indicated t ... | 1989 | 2619324 |
| purification and properties of novel molluscan metallothioneins. | two low-molecular-mass cadmium-induced, cadmium-, zinc-binding proteins were purified from the oyster crassostrea virginica using procedures that included acetone precipitation, sephadex gel chromatography, and anion-exchange and reverse-phase high-performance liquid chromatography. although they could be cleanly separated from each other, they exhibited similar molecular weights, metal and amino acid compositions, and electrophoretic behavior. these proteins were glycine-rich, in addition to be ... | 1989 | 2774559 |