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reactive oxygen intermediate production by oyster hemocytes exposed to hypoxiaoysters 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) ...199910539962
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 ...199910542227
effects of a commercial heat-shock process on vibrio vulnificus in the american oyster, crassostrea virginica, harvested from the gulf coast.oysters (crassostrea virginica) harvested from the gulf coast, containing 10(2) to 10(4) most probable number (mpn) per gram of vibrio vulnificus, were subjected to a commercial heat-shock process. after 1 to 4 min at internal oyster meat temperatures exceeding 50 degrees c, shellstock oysters were shucked, chilled, washed, and packed. v. vulnificus and total bacterial levels in gulf coast oysters were significantly reduced from 1 to 4 logs in the finished product. similar reductions were not ob ...199910571315
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 ...200610614868
patterns in metazoan parasite communities of some oyster species.metazoan parasite communities of crassostrea gigas and ostrea edulis from great britain, crassostrea virginica from mexico, and saccostrea commercialis from australia are described and summarized in terms of species composition, species richness, total number of individuals and dominance. metazoan parasite communities in all host species were composed of turbellarians and the metacercarial stage of digeneans, with the exception of s. commercialis where only metacercariae were found. arthropods, ...199910654396
whole animal and gill tissue oxygen uptake in the eastern oyster, crassostrea virginica: effects of hypoxia, hypercapnia, air exposure, and infection with the protozoan parasite perkinsus marinus(1).the eastern oyster, crassostrea virginica, lives in shallow coastal waters and experiences many different environmental extremes including hypoxia, hypercapnia and air exposure and many oysters are infected with the protozoan parasite perkinsus marinus. the effects of these conditions on oyster metabolism, as measured by oxygen uptake, were investigated. mild hypercapnia had no effect on the ability of oysters to regulate oxygen uptake in hypoxic water, as measured by the b2 coefficient of oxyge ...200010713278
selective accumulation may account for shellfish-associated viral illness.from 1991 through 1998, 1,266 cases of shellfish-related illnesses were attributed to norwalk-like viruses. seventy-eight percent of these illnesses occurred following consumption of oysters harvested from the gulf coast during the months of november through january. this study investigated the ability of eastern oysters (crassostrea virginica) to accumulate indicator microorganisms (i.e., fecal coliforms, escherichia coli, clostridium perfringens, and f(+) coliphage) from estuarine water. one-w ...200010742214
changes in the electrophoretic profiles of gill mucus proteases of the eastern oyster crassostrea virginica in response to infection by the turbellarian urastoma cyprinae.urastoma cyprinae occurs on the gills of various bivalves species, including the eastern oyster crassostrea virginica. while the worm is known to cause severe gill disruption in mussels, no evidence of this nature has been described for oysters. nonetheless, high levels of u. cyprinae have been reported in oysters, which may, in turn, reduce the oyster's overall condition. u. cyprinae is strongly attracted to oyster gill mucus, which is suggested to play an active role in the worm's feeding acti ...200010772329
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 ...200010935519
a quantitative competitive polymerase chain reaction assay for the oyster pathogen perkinsus marinus.a quantitative competitive polymerase chain reaction (qcpcr) assay was developed for the oyster parasite perkinsus marinus. pcr primers for the rrna gene region of p. marinus amplified dna isolated from p. marinus but not from perkinsus atlanticus, crassostrea virginica, or the dinoflagellates peridinium sp., gymnodinium sp., or amphidinium sp. a mutagenic primer was used to create a competitor plasmid molecule identical to the p. marinus target dna sequence except for a 13-bp deletion. both p. ...200010958465
detection of bonamia ostreae based on small subunit ribosomal probe.bonamia ostreae is a protozoan parasite of the flat oyster, ostrea edulis, which has caused significant loss of oysters in europe over the last decade. b. ostreae was purified from infected flat oysters and dna was extracted. the nearly complete small subunit rdna gene of b. ostreae was amplified using universal oligonucleotides and the pcr product was cloned and sequenced. blast research with this sequence revealed similarities to haplosporidium nelsoni, haplosporidium costale, and minchinia te ...200010963400
additional evidence that juvenile oyster disease is caused by a member of the roseobacter group and colonization of nonaffected animals by stappia stellulata-like strains.juvenile oyster disease (jod) causes significant annual mortalities of hatchery-produced eastern oysters, crassostrea virginica, cultured in the northeast. we have reported that a novel species of the alpha-proteobacteria roseobacter group (designated cvsp) was numerically dominant in jod-affected animals sampled during the 1997 epizootic on the damariscotta river, maine. in this study we report the isolation of cvsp bacteria from jod-affected oysters during three separate epizootics in 1998. th ...200010966410
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 ...200010967396
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 ...200010998504
transmission of the haplosporidian parasite msx haplosporidium nelsoni to the eastern oyster crassostrea virginica in an upweller system.the haplosporidian oyster parasite msx (multinucleated sphere x) haplosporidium nelsoni was transmitted to eastern oysters crassostrea virginica. hatchery-raised, msx-free juvenile oysters were placed in upweller tanks. water to the tanks was filtered through a screen with 1 mm2 openings and originated from the water column overlaying naturally infected oysters beds (msx prevalence 17 to 57%). msx was diagnosed by histopathological analysis. msx-disease (57% prevalence) with increased mortality ...200011023255
uptake and interconversion of fluorescent lipid analogs in the protozoan parasite, perkinsus marinus, of the oyster, crassostrea virginica.uptake, distribution, and interconversion of fluorescent lipid analogs (phosphatidylcholine, pc; cholesteryl ester, che; phosphatidylethanolamine, pe; palmitic acid, c16; sphingomyelin, sm) by the two life stages, meront and prezoosporangium, of the oyster protozoan parasite, perkinsus marinus, were investigated. class composition of these two life stages and lipid contents in meront cells were also examined. both meronts and prezoosporangia incorporated and modified fluorescent lipids from the ...200011038307
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 ...200011092737
characterization of microsatellite loci in the eastern oyster, crassostrea virginica 200011123661
evaluation of two direct plating methods using nonradioactive probes for enumeration of vibrio parahaemolyticus in oysters.oysters (crassostrea virginica) were collected monthly from may 1998 to april 1999 from mobile bay, ala., and analyzed to determine vibrio parahaemolyticus densities at zero time and after 5, 10, and 24 h of postharvest storage at 26 degrees c. after 24 h of storage at 26 degrees c, oysters were transferred to a refrigerator at 3 degrees c and then analyzed 14 to 17 days later. the v. parahaemolyticus numbers were determined by the most-probable-number procedure using alkaline phosphatase-labele ...200111157236
a unique sialidase that cleaves the neu5gcalpha2-->5-o(glycolyl)neu5gc linkage: comparison of its specificity with that of three microbial sialidases toward four sialic acid dimers.we found that the hepatopancreas of oyster, crassostrea virginica, contained a sialidase capable of releasing neu5gc from the novel polysialic acid chain (-->5-o(glycolyl)neu5gcalpha2-->)n more efficiently than from the conventional type of polysialic acid chains, (-->8neu5acalpha2-->)n, or (-->8neu5gcalpha2-->)n. we have partially purified this novel sialidase and compared its reactivity with that of microbial sialidases using four different sialic acid dimers, neu5gcalpha2-->5-o(glycolyl)neu5g ...200111162485
characterization of microsatellite loci in the eastern oyster, crassostrea virginica. 200011188988
lipid class composition of the protozoan perkinsus marinus, an oyster parasite, and its metabolism of a fluorescent phosphatidylcholine analog.perkinsus marinus is one of two important protozoan parasites of the eastern oyster, crassostrea virginica. the other is haplosporidium nelsoni. lipids extracted from 7-d-old in vitro cultured p. marinus meronts, incubated with fluorescent-labeled phosphatidylcholine (fl pc) and nonincubated p. marinus meronts, were analyzed by a high-performance liquid chromatography (hplc) system equipped with a diol phase column, in combination with thin-layer chromatography coupled with a flame-ionization de ...200011202001
characterization of microsatellite loci in the eastern oyster, crassostrea virginica. 200011221805
use of competitive pcr to detect and quantify haplosporidium nelsoni infection (msx disease) in the eastern oyster (crassostrea virginica).this study was undertaken to develop a quantitative polymerase chain reaction assay that would improve the utility of pcr for detecting haplosporidium nelsoni (msx), a serious parasite of the eastern oyster crassostrea virginica. a competitive pcr sequence was generated from the h. nelsoni small subunit ribosomal dna fragment, originally described by stokes and colleagues, that was amplified by the same pcr primers and had similar amplification performance. assays performed using competitor dilu ...200011246412
description of perkinsus andrewsi n. sp. isolated from the baltic clam (macoma balthica) by characterization of the ribosomal rna locus, and development of a species-specific pcr-based diagnostic assay.a perkinsus species was isolated from the baltic clam macoma balthica and an in vitro culture established under conditions described for p. marinus. as reported previously, morphological features remarkable enough to clearly indicate that this isolate is a distinct perkinsus species were lacking. in this study, regions of the rrna locus (nts, 18s, its1, 5.8s, and its2) of this isolate were cloned, sequenced, and compared by alignment with those available for other perkinsus species and isolates. ...200111249193
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 ...200011285737
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, ...200111351531
habitat-related predation on juvenile wild-caught and hatchery-reared red drum sciaenops ocellatus (linnaeus).we examined the patterns of habitat-specific mortality for newly settled red drum (sciaenops ocellatus) using an experimental mesocosm approach. experiments were designed to analyze prey vulnerability and fish rearing-type (wild-caught or hatchery-reared) in estuarine habitats of varying structural complexity including marsh (spartina alterniflora loisel), oyster reef (crassostrea virginica gmelin), seagrass (halodule wrightii aschers), and nonvegetated sand bottom. we used two different predato ...200111358569
elimination of fecal coliforms and f-specific rna coliphage from oysters (crassostrea virginica) relaid in floating containers.declining oyster (crassostrea virginica) production in the chesapeake bay has stimulated aquaculture based on floats for off-bottom culture. while advantages of off-bottom culture are significant, the increased use of floating containers raises public health and microbiological concerns, because oysters in floats may be more susceptible to fecal contamination from storm runoff compared to those cultured on-bottom. we conducted four commercial-scale studies with market-size oysters naturally cont ...200111403128
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 ...200111409690
ultrastructural characteristics of the in vitro cell cycle of the protozoan pathogen of oysters, perkinsus marinus.ultrastructural characteristics of vegetative and zoosporangial stages of cultured perkinsus marinus, a pathogen of the eastern oyster, crassostrea virginica, were examined by transmission electron microscopy. an axenic cell culture was propagated from infected chesapeake bay oyster hemolymph. different stages of the in vitro cell cycle, including schizonts and different size trophonts, were examined. trophonts had spherical nuclei with wide perinuclear spaces, mitochondria with tubular cristae, ...200111411844
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 ...200111445087
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 ...200111451426
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 ...201311460691
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 ...201311460693
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 ...201311460715
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 ...201311460732
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 ...200111488357
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 ...200111489306
rapid and efficient extraction method for reverse transcription-pcr detection of hepatitis a and norwalk-like viruses in shellfish.as part of an effort to develop a broadly applicable test for norwalk-like viruses and hepatitis a virus (hav) in shellfish, a rapid extraction method that is suitable for use with one-step reverse transcription (rt)-pcr-based detection methods was developed. the method involves virus extraction using a ph 9.5 glycine buffer, polyethylene glycol (peg) precipitation, tri-reagent, and purification of viral poly(a) rna by using magnetic poly(dt) beads. this glycine-peg-tri-reagent-poly(dt) method c ...200111526018
cristispira from oyster styles: complex morphology of large symbiotic spirochetes.crystalline styles (digestive organs) of bivalve mollusks provide the habitat for highly motile bacteria. styles from freshly-collected oysters, crassostrea virginica, were studied by electron microscopy; cristispira spirochetes were abundant in these organs. detailed study reveals these spirochetes to be among the most complex prokaryotic cells known. more than 600 periplasmic flagella and an adhering outer lipoprotein membrane (e.g., a 270 degrees sillon) form the ultrastructural basis for ...199111538110
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 ...200111595310
levels of vibrio vulnificus and organoleptic quality of raw shellstock oysters (crassostrea virginica) maintained at different storage temperatures.temperature abuse during raw oyster harvesting and storage may allow for the multiplication of natural spoilage flora as well as microbial pathogens, thus posing a potential health threat to susceptible consumers and compromising product quality. the objective of this study was to provide a scientific basis for determining whether different refrigeration and abuse temperatures for raw oysters would result in a spoiled product before it became unsafe. raw shellstock oysters (crassostrea virginica ...200111726149
cellular responses and disease expression in oysters (crassostrea virginica) exposed to suspended field contaminated sediments.exposure of oysters to water soluble fractions derived from field-contaminated sediments (fcs) containing predominantly lower molecular weight organic aromatic compounds, has been previously demonstrated to enhance pre-existing infections caused by the protozoan parasite, perkinsus marinus (dermo), and the prevalence of experimentally induced infections. to further explore the role of pollution on the onset and progression of disease, effects of suspended fcs from an estuarine creek in virginia, ...200211767253
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 ...200111812117
de novo arachidonic acid synthesis in perkinsus marinus, a protozoan parasite of the eastern oyster crassostrea virginica.the capability of synthesizing fatty acids de novo in the meront stage of the oyster protozoan parasite, perkinsus marinus, was investigated employing stable-isotope-labeled precursors (1,2 13c-acetate and palmitic-d(31) acid). fatty acid methyl esters derived from 1,2 13c-acetate and palmitic-d(31) acid were analyzed using gas chromatography/mass spectrometry and gas chromatography/flame ionization detection. results revealed that in vitro cultured p. marinus meronts utilized 13c-acetate to syn ...200211814570
development of a multiplex pcr for the detection of haplosporidium nelsoni, haplosporidium costale and perkinsus marinus in the eastern oyster (crassostrea virginica, gmelin, 1971).haplosporidium costale (sso), haplosporidium nelsoni (msx) and perkinsus marinus (dermo) have caused oyster mortality on the north american east coast since the 1950s. currently, the monitoring of oyster populations for these pathogens depends on histopathology for h. nelsoni, h. costale and the ray/mackin assay for p. marinus. in this study we describe the development and optimization of a multiplex polymerase chain reaction (mpcr) for the detection of h. nelsoni, h. costale and p. marinus. in ...200111851382
effects of plasma from bivalve mollusk species on the in vitro proliferation of the protistan parasite perkinsus marinus.the in vitro culture of the eastern oyster parasite perkinsus marinus has provided a unique opportunity to examine its susceptibility to putative recognition and effector defense mechanisms operative in refractory bivalve species. in this study, we report the effect of supplementing the culture medium with plasma from: (1) uninfected to heavily infected eastern oysters; (2) oyster species considered to be disease-resistant; and (3) bivalve mollusk species that are naturally exposed to the parasi ...200211857456
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 ...200211874050
laboratory studies of cryopreservation of sperm and trochophore larvae of the eastern oyster.the eastern oyster, crassostrea virginica, is the most important cultured oyster species of the atlantic and gulf coasts of the united states. cryopreservation of gametes and larvae of aquatic organisms has increased in importance in recent years. however, studies on the cryopreservation of sperm and larvae of mollusks have focused on the pacific oyster, crassostrea gigas. the present study was conducted to improve cryopreservation of sperm and trochophore larvae and to assess fertilizing abilit ...200111888215
detection of oyster herpesvirus dna and proteins in asymptomatic crassostrea gigas adults.since 1972, several herpes-like virus infections have been reported among different bivalve species around the world. most of these reports involved larvae or juveniles presenting high mortalities. two case reports of herpes-like viruses concerned adult oysters, crassostrea virginica in usa and ostrea angasi in australia. molecular techniques including pcr and in situ hybridization (ish) have been recently developed to detect the oyster herpesvirus genome. in the present study, 30 pacific oyster ...200211900847
removal of toxoplasma gondii oocysts from sea water by eastern oysters (crassostrea virginica).toxoplasma gondii infections have been reported in a number of marine mammals. presently it is not known how these animals acquire t. gondii from their aquatic environment. the eastern oyster, crassostrea virginica, has been shown to remove cryptosporidiwn oocysts from seawater and a similar phenomenon may be occurring with t. gondii oocysts and marine invertebrates. the present study was done to determine if eastern oysters could remove and retain t. gondii oocysts from seawater. oocysts of the ...200111906061
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.200211910459
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. ...200211939295
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 ...200211959018
phospholipid biosynthesis in the oyster protozoan parasite, perkinsus marinus.perkinsus marinus is a protozoan parasite that causes high mortality in its commercially and ecologically important host, the eastern oyster crassostrea virginica. in order to understand the host-parasite relationship in lipid metabolism, the ability of p. marinus to synthesize phospholipids from polar headgroup precursors was investigated. pulse/chase experiments were conducted using radiolabled serine, choline, ethanolamine and inositol. timecourse incubations revealed that in vitro cultured p ...200212034458
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 ...200212054781
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 ...200212069313
growth and survival of vibrio parahaemolyticus in postharvest american oysters.oysters at the retail stage of distribution generally contain greater densities of vibrio parahaemolyticus than do oysters at harvest. the objective of this study was to determine the effects of postharvest storage at 26 and 3 degrees c on the growth and survival of naturally occurring v. parahaemolyticus in shellstock american oysters (crassostrea virginica). oysters were collected monthly from may 1998 through april 1999 from mobile bay, alabama, and their v. parahaemolyticus densities were de ...200212092730
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 ...200212148944
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 ...200212175608
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 ...200212200083
temporal variability of cryptosporidium in the chesapeake bay.although cryptosporidium has been found worldwide in molluscan shellfish from waters contaminated with human and animal feces, little or no related environmental data have been obtained. in the present study, oysters ( crassostrea virginica) were collected eight times over 3 years from seven sites in the chesapeake bay or its tributaries, with accompanying data on water temperature, salinity, rainfall, and streamflow. oyster gill washings were examined by immunofluorescence microscopy for crypto ...200212375166
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 ...200212400864
protease inhibitors and haemagglutinins associated with resistance to the protozoan parasite, perkinsus marinus, in the pacific oyster, crassostrea gigas.perkinsus marinus is a protozoan responsible for dramatic mortality in the eastern oyster, crassostrea virginica, but not in the pacific oyster, c. gigas. to understand the host-parasite relationship, we inoculated p. marinus trophozoites into the shell cavity of c. gigas and measured, over 2 months, (i) intensity of infection, (ii) protease inhibitory activities against p. marinus proteases and against bovine z-chymotrypsin, (iii) plasma haemagglutinin titre, (iv) plasma protein concentration, ...200212403320
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 ...200612408652
comparison of in vitro-cultured and wild-type perkinsus marinus. i. pathogen virulence.perkinsus marinus is a highly contagious pathogen of the eastern oyster crassostrea virginica. until recently, transmission studies have employed wild-type parasites isolated directly from infected oysters. newly developed methods to propagate p. marinus in vitro have led to using cultured parasites for infection studies, but results suggest that cultured parasites are less virulent than wild-type parasites in this paper, we report results of experiments designed to quantify differences between ...200212465877
comparison of in vitro-cultured and wild-type perkinsus marinus. ii. dosing methods and host response.endoparasites must breach host barriers to establish infection and then must survive host internal defenses to cause disease. such barriers may frustrate attempts to experimentally transmit parasites by 'natural' methods. in addition, the host's condition may affect a study's outcome. the experiments reported here examined the effect of dosing method and host metabolic condition on measures of virulence for the oyster parasite perkinsus marinus. oysters, crassostrea virginica, were challenged wi ...200212465878
comparison of in vitro-cultured and wild-type perkinsus marinus. iii. fecal elimination and its role in transmission.perkinsus marinus, a pathogen of the eastern oyster crassostrea virginica, is transmitted directly among oysters. previous studies found viable p. marinus parasites in the feces and pseudofeces of oysters within hours of injection with parasites, suggesting that the parasite may be voided from live oysters and subsequently dispersed in the water column. the experiments described here were designed to quantify p. marinus shed in the feces and pseudofeces of experimentally infected oysters. the re ...200212465879
use of diacetyl to reduce the load of vibrio vulnificus in the eastern oyster, crassostrea virginica.vibrio vulnificus is a highly virulent human pathogen that occurs naturally among the microflora of oysters. this organism has two portals of entry into humans, one of which is ingestion. oysters containing v. vulnificus consumed in a raw or undercooked state often serve as a vehicle for the transmission of this organism. previous studies conducted in our laboratory have examined various generally recognized as safe compounds and have determined that diacetyl, a component of butter, is among the ...200312540179
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 ...200312558158
persistence of hepatitis a virus in oysters.we investigated the ability of hepatitis a virus (hav) to persist for up to 6 weeks in eastern oysters (crassostrea virginica). viral rna was detected by reverse transcription-polymerase chain reaction 6 weeks after 16 h of exposure to 90,000 pfu (180 pfu/ml of seawater) of hav. assaying for infectious virus in oysters that received a daily feeding of phytoplankton recovered 3,800, 650, and 500 pfu of hav 1, 2, and 3 weeks after contamination with 90,000 pfu of hav, respectively. however, no inf ...200312597498
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 ...200312608573
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 ...200312612834
passage of a coccidial parasite (eimeria acervulina) through the eastern oyster (crassostrea virginica).human illness resulting from the consumption of raw oysters is well documented for bacterial and viral pathogens but not for coccidial parasites. this study explores the passage of coccidial parasites through and the viability of these parasites in the eastern oyster, crassostrea virginica. because both cryptosporidium and toxoplasma are human parasites and are not safe to handle, we chose to work with a close relative, eimeria acervulina, as a surrogate. this parasite was analyzed in chickens. ...200312696696
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 ...200312738263
host oyster tissue extracts modulate in vitro protease expression and cellular differentiation in the protozoan parasite, perkinsus marinus.perkinsus marinus is responsible for a chronic disease (dermo) of the eastern oyster, crassostrea virginica. in order to simulate the in vivo environment more closely, a chemically defined medium (jl-odrp-3) was supplemented with tissue homogenate extracts or plasma from oysters possessing varying degrees of susceptibility to p. marinus infection. in media supplemented with extracts from highly susceptible oysters (c. virginica), p. marinus cells secreted elevated amounts of a set of low molecul ...200312741508
superoxide dismutases from the oyster parasite perkinsus marinus: purification, biochemical characterization, and development of a plate microassay for activity.we have isolated and biochemically characterized superoxide dismutase (sod) activity in cell extracts of clonally cultured perkinsus marinus, a facultative intracellular parasite of the eastern oyster, crassostrea virginica. in order to assess the sod activity throughout the purification, we developed and optimized a 96-well-plate microassay based on the inhibition of pyrogallol oxidation. the assay was also adapted to identify sod activity type (cu/zn-, mn-, or fesod), even in mixtures of more ...200312782041
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 ...200312807709
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 ...200312878408
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 ...200312878409
bivalve immunity: comparisons between the marine mussel (mytilus edulis), the edible cockle (cerastoderma edule) and the razor-shell (ensis siliqua).much of the current knowledge concerning bivalve immunology and immunotoxicology has come from studies on the mussel genus, mytilus, or from the american oyster, crassostrea virginica. following a major oil spill, it was observed that the marine mussel, mytilus edulis, underwent significant immunosuppression but no oil-induced mortalities, while in contrast, mass mortalities were noted in the edible cockle, cerastoderma edule, and the razor-shell, ensis siliqua. a study comparing immune cells an ...200312892742
studies on shell formation. vii. the submicroscopic structure of the shell of the oyster crassostrea virginica.the submicroscopic structure of the growing surface of the shell of the oyster, crassostrea virginica, was studied by means of shadowed replicas. the outer edge of the prismatic region consists of a fine grained matrix enclosing crystals, the surfaces of which show a finely pebbled structure. crystal size varies continously from 0.01 micro to 8 micro. the matrix surface shows no evidence of fibrous structure. the outer portions of the prismatic region exhibit a tile-like arrangement of large cry ...195813549498
studies on shell formation. viii. electron microscopy of crystal growth of the nacreous layer of the oyster crassostrea virginica.electron microscope observations have been made by means of the replica method on growth processes of calcite crystals of the nacreous layer of the shell of the oyster, crassostrea virginica. layer formation is initiated by the secretion of a conchiolin matrix and the deposition of rounded crystal seeds on or in this material. in some areas crystal seeds are elongate and within a given area show a similar orientation, probably due to slower deposition. the seeds appear to increase in size by den ...195813549499
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 ...200313678848
studies on shell formation. ix. an electron microscope study of crystal layer formation in the oyster.details of crystal growth in the calcitostracum of crassostrea virginica have been studied with the purpose of analyzing the formation of the overlapping rows of oriented tabular crystals characteristic of this part of the shell. crystal elongation, orientation, and dendritic growth suggest the presence of strong concentration gradients in a thin layer of solution in which crystallization occurs. formation of the overlapping rows can be explained by three processes observed in the shell: a two-d ...196113783329
cytology of glycogen and lipid storage in the pallium of crassostrea virginica (gmelin). 195913811410
ultrastructure of the spermatozoon of the oyster. crassostrea virginica. 196013826203
the accumulation of enteric viruses by the oyster, crassostrea virginica. 196514258479
the relationship between the flagellate protozoon hexamita and the oyster crassostrea virginica. 196214498204
systematic evaluation of factors controlling perkinsus marinus transmission dynamics in lower chesapeake bay.the transmission of perkinsus marinus in eastern oysters crassostrea virginica in relation to water temperature, host oyster mortality, and water-column abundance of anti-p. marinus antibody-labeled cells was systematically examined for 20 mo at a site in the lower york river, virginia, usa. uninfected sentinel oysters were naturally exposed to the parasite at 2 wk intervals throughout the course of the study to determine the periodicity and rates of parasite transmission. the timing and magnitu ...200314524504
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 ...200414559258
electron and light microscopic study of various glands and the secretions released into the environment by the turbellarian urastoma cyprinae.the turbellarian urastoma cyprinae (graff) occurs on the gills of various bivalve species including the mussel mytilus galloprovinciallis, where it is known to cause serious damage. more recently, it has been shown that the worms are strongly attracted to the gill of the american oyster (crassostrea virginica) and are capable of inducing changes to the composition of proteolytic enzymes of the host mucus. such changes may be attributable to secretory products released by the worms. mucous glands ...200314584032
apoptosis in the pathogenesis of infectious diseases of the eastern oyster crassostrea virginica.apoptosis, or programmed cell death, has been reported as being pivotal in infectious diseases of different organisms. the effects of apoptosis on the progression and transmission of the protistan parasites perkinsus marinus and haplosporidium nelsoni in the eastern oyster crassostrea virginica were studied. oysters were diagnosed for their respective infections by standard methods, and apoptosis was detected using in situ hybridization to detect dna fragments by end labeling on paraffin section ...200314598992
protease activity in the plasma of american oysters, crassostrea virginica, experimentally infected with the protozoan parasite perkinsus marinus.perkinsus marinus is responsible for disease and mortality of the american oyster, crassostrea virginica. to investigate the interactions between p. marinus and oyster hemocytes, protease activity was measured in plasma of oysters collected 4 hr, 24 hr, 4 days, and 2 mo after experimental infection with p. marinus. a significant increase in protease activity was observed in oyster plasma 4 hr after injection with p. marinus, followed by a sharp decrease within 24 hr. gelatin-impregnated gel elec ...200314627141
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 ...200314644349
supplementation of perkinsus marinus cultures with host plasma or tissue homogenate enhances their infectivity.the protozoan oyster parasite perkinsus marinus can be cultured in vitro in a variety of media; however, this has been associated with a rapid attenuation of infectivity. supplementation of defined media with products of p. marinus-susceptible (crassostrea virginica) and -tolerant (crassostrea gigas, crassostrea ariakensis) oysters alters proliferation and protease expression profiles and induces differentiation into morphological forms typically seen in vivo. it was not known if attenuation cou ...200414711671
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 ...200214961291
a centromeric satellite sequence in the pacific oyster (crassostrea gigas thunberg) identified by fluorescence in situ hybridization.a highly repetitive satellite sequence was previously identified in the pacific oyster crassostrea gigas thunberg. the sequence has 168 bp per unit, present in tandem repeats, and accounts for 1% to 4% of the genome. we studied the chromosomal location of this satellite sequence by fluorescence in situ hybridization (fish). a probe was made by polymerase chain reaction and incorporation of digoxigenin-11-dutp. hybridization was detected with fluorescein-labeled antidigoxigenin antibodies. fish s ...200114961342
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 ...200114961348
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