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
histology, ultrastructure, and morphogenesis of a rickettsia-like organism causing disease in the oyster, crassostrea ariakensis gould.moribund specimens of the oyster, crassostrea ariakensis gould, aged 2-3 years were collected from hailing bay in yangxi county of guangdong province from february to may and november to december in the years 2001, 2002, and 2003. a massive infection by an obligate intracellular prokaryote, specifically a rickettsia-like organism (rlo), was found. here we report investigations of this rlo in the tissues of the oyster c. ariakensis gould and describe the histology, ultrastructure, and morphogenes ...200415261771
genetic variation in wild and hatchery stocks of suminoe oyster (crassostrea ariakensis) assessed by pcr-rflp and microsatellite markers.genetic variation in wild asian populations and u.s. hatchery stocks of crassostrea ariakensis was examined using polymerase chain reactions with restriction fragment length polymorphism (pcr-rflp) analysis of both the mitochondrial coi gene and the nuclear internal transcribed spacer (its) 1 region and using 3 microsatellite markers. hierarchical analysis of molecular variance and pairwise comparisons revealed significant differentiation (p < 0.05) between samples from the northern region, repr ...200516027991
purification and antigenic characteristics of a rickettsia-like organism from the oyster crassostrea ariakensis.a rickettsia-like organism (rlo) has been suggested to be the etiological agent responsible for heavy losses of the oyster crassostrea ariakensis gould in china. because of the lack of molluscan cell lines for in vitro culture of intracellular prokaryotes, antigenic analysis of rlos has been limited by the inherent difficulties of their purification. in this report, we describe the use of differential speed centrifugation and renografin density gradient centrifugation to purify the rlo directly ...200516385821
hsp70 gene expression in mytilus galloprovincialis hemocytes is triggered by moderate heat shock and vibrio anguillarum, but not by v. splendidus or micrococcus lysodeikticus.complete sequence of hsp70 cdna from the mussel, mytilus galloprovincialis was established before quantifying its expression following moderate heat shock or injection of heat-killed bacteria. hsp70 cdna is comprised of 2378 bp including one orf of 654 aa, with a predicted 70 bp 5'-utr and a 343 bp 3'-utr (genbank, 18 jan 05, ay861684). alignment identity ranged from 89% for crassostrea ariakensis to 72% for c. virginica. curiously, hsp70 gene and cdna sequences from m. galloprovincialis, deposi ...200616476480
recovery, bioaccumulation, and inactivation of human waterborne pathogens by the chesapeake bay nonnative oyster, crassostrea ariakensis.the introduction of nonnative oysters (i.e., crassostrea ariakensis) into the chesapeake bay has been proposed as necessary for the restoration of the oyster industry; however, nothing is known about the public health risks related to contamination of these oysters with human pathogens. commercial market-size c. ariakensis triploids were maintained in large marine tanks with water of low (8-ppt), medium (12-ppt), and high (20-ppt) salinities spiked with 1.0 x 10(5) transmissive stages of the fol ...200616672482
when r-selection may not predict introduced-species proliferation: predation of a nonnative oyster.predicting outcomes of species introductions may be enhanced by integrating life-history theory with results of contained experiments that compare ecological responses of exotic and analogue native species to dominant features of the recipient environment. an asian oyster under consideration for introduction to the chesapeake bay, usa, the rapidly growing suminoe oyster (crassostrea ariakensis), may not be as successful an invader as its r-selected life history suggests if the trade-off for rapi ...200616711058
bonamia perspora n. sp. (haplosporidia), a parasite of the oyster ostreola equestris, is the first bonamia species known to produce spores.examination of the oyster ostreola equestris as a potential reservoir host for a species of bonamia discovered in crassostrea ariakensis in north carolina (nc), usa, revealed a second novel bonamia sp. histopathology, electron microscopy, and molecular phylogenetic analysis support the designation of a new parasite species, bonamia perspora n. sp., which is the first bonamia species shown to produce a typical haplosporidian spore with an orifice and hinged operculum. spores were confirmed to be ...200616872291
pathogens in crassostrea ariakensis and other asian oyster species: implications for non-native oyster introduction to chesapeake bay.with the drastic decline of eastern oyster crassostrea virginica populations in the chesapeake bay due to over-fishing, diseases and habitat destruction, there is interest in maryland and virginia in utilizing the non-native oyster species crassostrea ariakensis for aquaculture, fishery resource enhancement, and ecological restoration. the international council for the exploration of the sea (ices) recommends that non-native species be examined for ecological, genetic and disease relationships i ...200718062472
description of perkinsus beihaiensis n. sp., a new perkinsus sp. parasite in oysters of southern china.oysters were collected from coastal locations in china from 1999-2006 for parasite analyses by molecular, culture, and histological techniques. polymerase chain reaction-based assays targeting the internal transcribed spacer (its) region of the ribosomal rna gene complex were performed to detect the presence of perkinsus species. sequencing and phylogenetic analysis of amplified perkinsus sp. dnas indicated that a novel perkinsus sp. infects crassostrea hongkongensis, crassostrea ariakensis, and ...200818318865
identification of outer membrane protein ompr from rickettsia-like organism and induction of immune response in crassostrea ariakensis.rickettsia-like organism (rlo) caused mass mortality of oysters, but little is known about the protective immune response to this microorganism. the present study was undertaken to identify a gene, ompr, encoding an outer membrane protein of rickettsia-like organism from oyster crassostrea ariakensis. the role of this protein in promoting immune responses was characterized through analyzing the interaction between rlo and oyster. the results indicated: (i) full-length dna of ompr is 531 bp and e ...200818395262
strong seasonality of bonamia sp. infection and induced crassostrea ariakensis mortality in bogue and masonboro sounds, north carolina, usa.asian oyster crassostrea ariakensis is being considered for introduction to atlantic coastal waters of the usa. successful aquaculture of this species will depend partly on mitigating impacts by bonamia sp., a parasite that has caused high c. ariakensis mortality south of virginia. to better understand the biology of this parasite and identify strategies for management, we evaluated its seasonal pattern of infection in c. ariakensis at two north carolina, usa, locations in 2005. small (<50 mm) t ...200818455182
interacting effects of temperature and salinity on bonamia sp. parasitism in the asian oyster crassostrea ariakensis.the proposition to introduce the asian oyster crassostrea ariakensis to the mid-atlantic region of the usa is being considered with caution, particularly after the discovery of a novel microcell haplosporidian parasite, bonamia sp., in north carolina. although this parasite was found to be pathogenic in c. ariakensis under warm euhaline conditions, its persistence in c. ariakensis exposed to various temperature and salinity combinations remained unresolved. in this laboratory experiment, we test ...200818456278
characterization and function of creb homologue from crassostrea ariakensis stimulated by rickettsia-like organism.the camp response element-binding protein (creb) is a transcription factor that plays important roles in cellular growth, proliferation and survival. here, we report that a homologue of creb transcription factor, ca-creb, was identified and functionally characterized in oyster, crassostrea ariakensis. the full-length cdna consists of 1397bp with an orf encoding a 39.3kda protein. amino acid sequence analysis revealed that ca-creb shares conserved signature motifs with other creb proteins. ca-cre ...200818606451
bioaccumulation, retention, and depuration of enteric viruses by crassostrea virginica and crassostrea ariakensis oysters.crassostrea ariakensis oysters are under review for introduction into the chesapeake bay. however, the human health implications of the introduction have not been fully addressed. this study evaluated rates of bioaccumulation, retention, and depuration of viruses by crassostrea virginica and c. ariakensis when the two oyster species were maintained in separate tanks containing synthetic seawater of various salinities (8, 12, or 20 ppt). oyster bioaccumulation tanks were seeded with 10(3) pfu/ml ...200818820067
tolliod-like gene in crassostrea ariakensis: molecular cloning, structural characterization and expression by rlo stimulation.the bmp1/tld-like proteinases are pleiotropic, astacin-like metalloproteinases. they play central roles in regulating the formation of the extracellular matrix (ecm) and signaling through various tgfbeta-like proteins in morphogenetic and homeostatic events. here we describe the cloning, structural characterization and expression of tolloid-like gene in the oyster, crassostrea ariakensis (catll). the full-length cdna of catll spans 3492 nucleotides including an open reading frame of 2811 nucleot ...200919105979
shellfish face uncertain future in high co2 world: influence of acidification on oyster larvae calcification and growth in estuaries.human activities have increased atmospheric concentrations of carbon dioxide by 36% during the past 200 years. one third of all anthropogenic co(2) has been absorbed by the oceans, reducing ph by about 0.1 of a unit and significantly altering their carbonate chemistry. there is widespread concern that these changes are altering marine habitats severely, but little or no attention has been given to the biota of estuarine and coastal settings, ecosystems that are less ph buffered because of natura ...200919478855
co-localized crassostrea virginica and crassostrea ariakensis oysters differ in bioaccumulation, retention and depuration of microbial indicators and human evaluate the bioaccumulation, retention and depuration rates of nine pathogens and surrogates when two oyster species were co-localized in tanks of seawater.201019735333
identification and functional characterization of a human strail homolog, castrail, in an invertebrate oyster crassostrea ariakensis.tumor necrosis factor-related apoptosis-inducing ligand (trail/apo2l) is one of the tumor necrosis factor (tnf) superfamily members, participating in many biological processes including apoptosis and immune responses. in present study, a novel human soluble trail (strail) homolog, castrail was identified from the oyster, crassostrea ariakensis. castrail has a 99% and 98% similarity to human strail over the cdna sequence and the amino acid sequence, respectively. it mostly distributes in tissues ...201020045024
development of an in vitro assay to examine intracellular survival of perkinsus marinus trophozoites upon phagocytosis by oyster (crassostrea virginica and crassostrea ariakensis) hemocytes.perkinsus marinus is a facultative intracellular parasite that causes "dermo" disease in the eastern oyster crassostrea virginica. although hemocytes from healthy oysters rapidly phagocytize p. marinus trophozoites, they fail to efficiently kill them. instead, trophozoites survive and proliferate, eventually overwhelming the host. because chesapeake bay oyster populations have been reduced to unprecedented levels, the introduction of the suminoe oyster, crassostrea ariakensis (synonymous c. rivu ...200920049995
biological characterization of two marine bdellovibrio-and-like organisms isolated from daya bay of shenzhen, china and their application in the elimination of vibrio parahaemolyticus in oyster.bdellovibrio-and-like organisms (balos) are a group of highly motile delta-proteobacteria that prey on other gram-negative bacteria. however, nothing is known of the application potential of marine balos in safeguarding seafood safety. here, biological characterization of two marine balos strains and their application in the elimination of vibrio parahaemolyticus in oyster (crassostrea ariakensis) at the laboratory scale were investigated. balos strains bdh12 and bdhsh06 were isolated from sedim ...201121899909
diseases of oysters crassostrea ariakensis and c. virginica reared in ambient waters from the choptank river, maryland and the indian river lagoon, assess potential benefits and liabilities from a proposed introduction of asian suminoe oysters, susceptibilities of exotic crassostrea ariakensis and native c. virginica oysters were compared during exposures to pathogens endemic in temperate, mesohaline waters of chesapeake bay and sub-tropical, polyhaline atlantic waters of southern florida, usa. cohorts of diploid, sibling oysters of both species were periodically tested for diseases while reared in mesocosms receiving ambient waters from ...201223324414
bonamia exitiosa transmission among, and incidence in, asian oyster crassostrea ariakensis under warm euhaline conditions.previously reported in australia, new zealand, and more recently in europe, the protistan parasite bonamia exitiosa was also reported in the mid-atlantic region of the usa after causing serious mortalities there in the asian oyster crassostrea ariakensis. at the time, this oyster was being considered for introduction, and the potential consequences of introducing this species were being assessed using field and laboratory studies. b. exitiosa emerged as the most serious disease threat for this o ...201425060506
detection and characterization of bonamia ostreae in ostrea edulis imported to china.the protozoan parasite bonamia ostreae is a destructive pathogen of flat oysters and has been reported to be widespread in europe and north america. the biological characteristics of this unicellular parasite are still not fully understood. in this study, 104 ostrea edulis imported from the usa to the guangdong province of china for consumption were examined for bonamia infection. pcr assay, combined with restriction fragment length polymorphism, sequencing and blast analysis, showed that b. ost ...201324062556
molecular and histological identification of marteilioides infection in suminoe oyster crassostrea ariakensis, manila clam ruditapes philippinarum and pacific oyster crassostrea gigas on the south coast of korea.the oyster ovarian parasite marteilioides chungmuensis has been reported from korea and japan, damaging the oyster industries. recently, marteilioides-like organisms have been identified in other commercially important marine bivalves. in this study, we surveyed marteilioides infection in the manila clam ruditapes philippinarum, suminoe oyster crassostrea ariakensis, and pacific oyster crassostrea gigas, using histology and marteilioides-specific small subunit (ssu) rdna pcr. the ssu rdna sequen ...201324018168
a novel molluscan fos gene with immune defense function identified in the hong kong oyster, crassostrea hongkongensis.the transcription factor fos is a member of one of the best-studied ap-1 sub-families and has been implicated in a wide variety of biological processes, including the regulation of apoptosis, immune responses and cytokine production. in this report, a novel mollusk fos (referred to as chfos) gene was cloned and characterized from the hong kong oyster, crassostrea hongkongensis. the deduced chfos protein sequence comprised 333 amino acids and shared significant homology with invertebrate homologs ...201525841657
development and validation of a predictive model for the growth of vibrio vulnificus in postharvest shellstock oysters.postharvest growth of vibrio vulnificus in oysters can increase risk of human infection. unfortunately, limited information is available regarding v. vulnificus growth and survival patterns over a wide range of storage temperatures in oysters harvested from different estuaries and in different oyster species. in this study, we developed a predictive model for v. vulnificus growth in eastern oysters (crassostrea virginica) harvested from chesapeake bay, md, over a temperature range of 5 to 30°c a ...201222247136
expression profile of eight glutathione s-transferase genes in crassostrea ariakensis after exposure to dsp toxins producing dinoflagellate prorocentrum this study, changes in eight gsts mrna level including gst-α, gst-σ, gst-ω, gst-π, gst-μ, gst-ρ, gst-θ and microsomal gst (mgst) in the oyster crassostrea ariakensis after exposure to prorocentrum lima have been evaluated by quantitative real-time pcr. additionally, the contents of five gst isoforms were detected by elisa. after exposure to p. lima at density of 2 × 10(5) cells/l, mgst mrna significantly increased in gill, while gst-σ was induced in digestive gland. after exposure to p. lima ...201526335360
spermiogenesis and taxonomical values of sperm ultrastructures in male crassostrea ariakensis (fujita & wakiya, 1929) (pteroirmorphia: ostreidae) in the estuary of the seomjin river, korea.characteristics of the developmental stages of spermatids during spermiogenesis and phylogenetic classicfication of the species using sperm ultrastructures in male crassostrea ariakensis were investigated by transmission electron microscope observations. the morphology of the spermatozoon of this species has a primitive type and is similar to those of ostreidae. ultrastructures of mature sperms are composed of broad, modified cap-shaped acrosomal vesicle and an axial rod in subacrosomal material ...201425949188
ultrastructural comparison of bonamia spp. (haplosporidia) infecting ostreid oysters.the ultrastructure of bonamia from ostrea angasi from australia, crassostrea ariakensis from the usa, o. puelchana from argentina and o. edulis from spain was compared with described bonamia spp. all appear conspecific with b. exitiosa. the bonamia sp. from chile had similarities to the type b. exitiosa from new zealand (nz), but less so than the other forms recognized as b. exitiosa. two groups of ultrastructural features were identified; those associated with metabolism (mitochondrial profiles ...201425060497
allograft inflammatory factor 1 functions as a pro-inflammatory cytokine in the oyster, crassostrea ariakensis.the oyster crassostrea ariakensis is an economically important bivalve species in china, unfortunately it has suffered severe mortalities in recent years caused by rickettsia-like organism (rlo) infection. prevention and control of this disease is a priority for the development of oyster aquaculture. allograft inflammatory factor-1 (aif-1) was identified as a modulator of the immune response during macrophage activation and a key gene in host immune defense reaction and inflammatory response. th ...201424759987
effect of simultaneous variation in temperature and ammonia concentration on percent fertilization and hatching in crassostrea ariakensis.the combined effects of temperature and ammonia concentration on the percent fertilization and percent hatching in crassostrea ariakensis were examined under laboratory conditions using the central composite design and response surface methodology. the results indicated: (1) the linear effects of temperature and ammonia concentration on the percent fertilization were significant (p<0.05), and the quadratic effects were highly significant (p<0.01). the interactive effect between temperature and a ...201424679971
shell hardness and compressive strength of the eastern oyster, crassostrea virginica, and the asian oyster, crassostrea ariakensis.the valves of oysters act as a physical barrier between tissues and the external environment, thereby protecting the oyster from environmental stress and predation. to better understand differences in shell properties and predation susceptibilities of two physiologically and morphologically similar oysters, crassostrea virginica and crassostrea ariakensis, we quantified and compared two mechanical properties of shells: hardness (resistance to irreversible deformation; gpa) and compressive streng ...201324445443
hmgb in mollusk crassostrea ariakensis gould: structure, pro-inflammatory cytokine function characterization and anti-infection role of its antibody.crassostrea ariakensis gould is a representative bivalve species and an economically important oyster in china, but suffers severe mortalities in recent years that are caused by rickettsia-like organism (rlo). prevention and control of this disease is a priority for the development of oyster aquaculture. it has been proven that mammalian hmgb (high mobility group box) can be released extracellularly and acts as an important pro-inflammatory cytokine and late mediator of inflammatory reactions. i ...201223209826
molecular characterization of a novel tetraspanin from the oyster, crassostrea ariakensis: variation, localization and relationship to oyster host defense.we identified a tetraspanin family member gene, named ca-tsp, in the oyster crassostrea ariakensis and found that the transcription profiles of ca-tsp were variable in the oyster hemocytes. three distinct patterns of variation of ca-tsp were observed. using immunofluorescence and immunoelectron microscopy, we show that ca-tsp was present in granules and in vesicular structures of the oyster hemocyte. sequence analysis, structural features and immunogold electron microscopy showed that ca-tsp is ...201222634254
identification of expressed genes in cdna library of hemocytes from the rlo-challenged oyster, crassostrea ariakensis gould with special functional implication of three complement-related fragments (cac1q1, cac1q2 and cac3).a smarter™ cdna library of hemocyte from rickettsia-like organism (rlo) challenged oyster, crassostrea ariakensis gould was constructed. random clones (400) were selected and single-pass sequenced, resulted in 200 unique sequences containing 96 known genes and 104 unknown genes. the 96 known genes were categorized into 11 groups based on their biological process. furthermore, we identified and characterized three complement-related fragments (cac1q1, cac1q2 and cac3). tissue distribution analysi ...201222484279
flow cytometry studies on the populations and immune parameters of the hemocytes of the suminoe oyster, crassostrea ariakensis.the suminoe oyster crassostrea ariakensis has been attempted to be introduced in the chesapeake bay, usa, as an alternative to the eastern oyster crassostrea virginica. commercial production of suminoe oysters is currently restricted due to the incomplete understanding of their biological, physiological and immunological nature. accordingly, understanding immune system of c. ariakensis is crucial to prevent disease associated mortality and subsequent management of the suminoe oyster. we investig ...200919490941
eleven novel microsatellite markers for the asian oyster crassostrea ariakensis.clones from four partial genomic libraries of the asian oyster crassostrea ariakensis were screened to reveal 64 microsatellite-containing sequences. polymerase chain reaction primers were designed for 34 of these loci. reactions were optimized for 11 primer pairs and markers were evaluated in eight family crosses and one wild population from northern china. zero to three null alleles per locus were identified in family crosses, and two of the 11 loci showed allele frequency deviations from hard ...200821585908
direct effects of physical stress can be counteracted by indirect benefits: oyster growth on a tidal elevation gradient.the paradigmatic gradient for intertidal marine organisms of increasing physical stress from low to high elevation has long served as the basis for using direct effects of duration of water coverage to predict many biological patterns. accordingly, changes in potential feeding time may predict the direction and magnitude of differences between elevations in individual growth rates of sessile marine invertebrates. oysters (triploid crassostrea ariakensis) experimentally introduced at intertidal ( ...200616249896
intraspecific variation in mitogenomes of five crassostrea species provides insight into oyster diversification and speciation.a large number of crassostrea oysters are found in asia-pacific. while analyses of interspecific variation have helped to establish historical relationships among these species, studies on intraspecific variation are necessary to understand their recent evolutionary history and current forces driving population biology. we resequenced 18 and analyzed 31 mitogenomes of five crassostrea species from china: crassostrea gigas, crassostrea angulata, crassostrea sikamea, crassostrea ariakensis, and cr ...201626846524
first characterization of three cyclophilin family proteins in the oyster, crassostrea ariakensis gould.cyclophilins (cyps) are a family of proteins that bind the immunosuppressive agent cyclosporin a (csa) with high-affinity and belong to one of the three superfamilies of peptidyl-prolyl cis-trans isomerases (ppiase). in this report, three cyclophilin genes (ca-cyps), including ca-cypa, ca-cypb and ca-ppil3, were identified from oyster, crassostrea ariakensis gould in which ca-cypa encodes a protein with 165 amino acid sequences, ca-cypb encodes a protein with 217 amino acid sequences and ca-ppil ...201627238430
densoviruses in oyster crassostrea ariakensis.densoviruses have short ssdna genomes and mainly infect arthropods. to characterize viral nucleic acid in shellfish, oysters (crassostrea ariakensis) were analyzed using viral metagenomics. two large de novo assembled contigs, caadv1 and caadv2, consisting of nearly complete densovirus genomes (5860 nucleotides (nt) and 4034 nt) with two major ambisense protein coding regions were identified. several potential non-structural proteins and capsid proteins were encoded by these genomes, but these w ...201728342032
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