PMID(sorted ascending)
evaluation of an experimental aeromonas salmonicida epidemic in chinook salmon, oncorhynchus tshawytscha (walbaum).to determine the dynamics of the transmission of aeromonas salmonicida ssp. salmonicida infection, chinook salmon, oncorhynchus tshawytscha, were exposed to bacteria by cohabitation. the latent period (time between exposure and infectivity) was determined by exposing a group of chinook salmonid fingerlings to a. salmonicida by bath, then, at daily intervals, by holding five exposed (donor) fish with approximately 50 naive fish for 24 h. the latent period was 3 days post-infection and the time pe ...200515892751
efficacy of an infectious hematopoietic necrosis (ihn) virus dna vaccine in chinook oncorhynchus tshawytscha and sockeye o. nerka salmon.the level of protective immunity was determined for chinook oncorhynchus tshawytscha and sockeye/kokanee salmon (anadromous and landlocked) o. nerka following intramuscular vaccination with a dna vaccine against the aquatic rhabdovirus, infectious hematopoietic necrosis virus (ihnv). a dna vaccine containing the glycoprotein gene of ihnv protected chinook and sockeye/kokanee salmon against waterborne or injection challenge with ihnv, and relative percent survival (rps) values of 23 to 86% were o ...200515900683
functional expression of a low-affinity zinc uptake transporter (frzip2) from pufferfish (takifugu rubripes) in mdck cells.zinc is a vital micronutrient to all organisms and it is therefore very important to determine the mechanisms that regulate cellular zinc uptake. previously, we reported on zinc uptake transporters from zebrafish (danio rerio; drzip1) and fugu pufferfish (takifugu rubripes; frzip1) that facilitated cellular zinc uptake of high affinity (k(m)<0.5 microm) in both chse214 [chinook salmon (oncorhynchus tshawytscha) embryonic 214] cells and xenopus laevis oocytes. to investigate additional biochemica ...200515907194
accumulation and clearance of orally administered erythromycin and its derivative, azithromycin, in juvenile fall chinook salmon oncorhynchus tshawytscha.fall chinook salmon oncorhynchus tshawytscha were fed practical diets medicated with azithromycin (30 mg kg(-1) fish for 14 d) or erythromycin (100 mg kg(-1) fish for 28 d) either 1, 2, or 3 times beginning 14 d after initiation of exogenous feeding (february) and ending at smoltification (june). average tissue concentrations of azithromycin increased from 19.0 microg g(-1) in fry to 44.9 microg g(-1) in smolts, and persisted in the tissues > 76 d after treatment ceased. tissue concentrations of ...200515918472
review of the sequential development of loma salmonae (microsporidia) based on experimental infections of rainbow trout (oncorhynchus mykiss) and chinook salmon (o. tshawytscha).loma salmonae is a common gill parasite of salmonids, and essentially all species in the genus oncorhynchus are susceptible. infections occur in both fresh and salt water. loma salmonae is directly transmissible by ingestion of spores or infected tissue. the parasite infects the wall of blood vessels of various organs, but the gill is the primary site of infection. initial infection occurs in the intestine, and xenomas are easily detected in the gills by standard histology at 4-6 wk post-exposur ...200516004365
circulating serotonin in vertebrates.the role of circulating serotonin is unclear and whether or not serotonin is present in the blood of non-mammalian species is not known. this study provides the first evidence for the presence of serotonin in thrombocytes of birds and three reptilian species, the endothermic leatherback sea turtle, the green sea turtle and the partially endothermic american alligator. thrombocytes from a fresh water turtle, american bullfrog, yellowfin tuna, and chinook salmon did not contain serotonin. serotoni ...200516041566
immunosuppression in progeny of chinook salmon infected with renibacterium salmoninarum: re-analysis of a brood stock segregation experiment.female spawner infection level and temperature variation through rearing are sufficient to explain in-hatchery mortality rates and infection levels and smolt to adult return ratios (sars) of progeny of renibacterium salmoninarum infected spring chinook salmon. data from published reports and manuscripts regarding a 1988 brood stock segregation experiment that held progeny of highly infected female spring chinook salmon spawners separate from progeny of other spawners during 16 mo of hatchery rea ...200516042041
synergistic effects of esfenvalerate and infectious hematopoietic necrosis virus on juvenile chinook salmon mortality.sublethal concentrations of pollutants may compromise fish, resulting in increased susceptibility to endemic pathogens. to test this hypothesis, juvenile chinook salmon (oncorhynchus tshawytscha) were exposed to sublethal levels of esfenvalerate or chlorpyrifos either alone or concurrently with infectious hematopoietic necrosis virus (ihnv). three trials were performed with fish exposed to concentrations of ihnv between 0.8 x 10(2) and 2.7 x 10(6) plaque-forming units/ml and to 5.0 microg/l of c ...200516050595
constitutive expression of atlantic salmon mx1 protein in chse-214 cells confers resistance to infectious salmon anaemia virus.infectious salmon anaemia (isa) is a highly fatal viral disease affecting marine-farmed atlantic salmon which is caused by isa virus (isav), a fish orthomyxovirus that has recently been assigned to the new genus isavirus within the family orthomyxoviridae. mx proteins are among the interferon (ifn)-induced proteins responsible for the development of an antiviral state in vertebrate cells. we used real-time reverse transcription-polymerase chain reaction (rt-pcr) and chinook salmon embryo (chse-2 ...200516124877
morphological presentation of a dendritic-like cell within the gills of chinook salmon infected with loma salmonae. 200616139356
release of persistent organic contaminants from carcasses of lake ontario chinook salmon (oncorhynchus tshawytscha).about 20,000 chinook salmon (oncorhynchus tshawytscha) from lake ontario enter the credit river, ontario, canada every fall to spawn and die. in this study, samples of muscle and eggs collected from female chinook salmon entering the credit river contained total pcbs, ddt compounds and other organochlorine (oc) compounds at mug/kg concentrations. semi-permeable membrane devices (spmds) were deployed at a reference site above the spawning grounds and at two downstream sites at intervals over a 14 ...200616169134
polychlorinated biphenyl concentrations in adult chinook salmon (oncorhynchus tshawytscha) returning to coastal and puget sound hatcheries of washington state.identifying the source of polychlorinated biphenyls (pcbs) is the first step to eliminating contamination within anadromous salmonids and other aquatic species. we evaluated pcb concentrations in the muscle tissue of 4-year old puget sound and coastal hatchery chinook salmon in an effortto identify potential locations where contamination occurs. ten muscle samples were taken from each of two puget sound hatcheries and two coastal hatcheries in washington state to determine pcb concentrations. tw ...200516201615
impact of environmental stressors on the dynamics of disease transmission.infectious disease within outmigrant juvenile salmon in the columbia river basin is modulated, in part, by abiotic stressors that influence host-susceptibility. through the application of a dose-structured population dynamic model, we show that chemical (both in the river and in the estuary) and in-river (e.g., dams and/or predation) stressors influence host-susceptibility, increasing the mean force of infection (defined as the per capita acquisition rate of infection) by a factor of 2.2 and 1.6 ...200516201666
use of sequence data from rainbow trout and atlantic salmon for snp detection in pacific salmon.single nucleotide polymorphisms (snps) are a class of genetic markers that are well suited to a broad range of research and management applications. although advances in genotyping chemistries and analysis methods continue to increase the potential advantages of using snps to address molecular ecological questions, the scarcity of available dna sequence data for most species has limited marker development. as the number and diversity of species being targeted for large-scale sequencing has incre ...200516262869
detection of renibacterium salmoninarum in chinook salmon, oncorhynchus tshawytscha (walbaum), using quantitative pcr.a quantitative polymerase chain reaction (qpcr) assay has been developed to detect varying levels of renibacterium salmoninarum, the causative agent of bacterial kidney disease. this assay allows for the direct enumeration of bacterial dna or rna copy number within tissues and body fluids. the assay can be applied non-lethally and can be used to determine whether r. salmoninarum is transcriptionally active. the presence of r. salmoninarum in kidney tissues from 430 chinook salmon collected from ...200516302955
features of the clear zone of odontoclasts in the chinook salmon (oncorhynchus tshawytscha).this study aims to clarify the features of the clear zone of odontoclasts on shedding teeth of a teleost fish, chinook salmon, oncorhynchus tshawytscha (walbaum), using a light microscope to determine the orientation between a cell body and a resorptive lacuna, followed by transmission electron microscopy. ultrathin sections of lr white embedded material were incubated in rabbit anti-actin polyclonal antibody and then were incubated with 15 nm gold-conjugated goat anti-rabbit igg. the clear zone ...200616328359
growth of fish cell lines on microcarriers.microcarrier beads were evaluated as substrates for the propagation of five anchorage-dependent fish cell lines. growth of rainbow trout gonad (rtg-2) and atlantic salmon cells was limited on microcarriers maintained in suspension. however, stationary microcarriers were suitable substrates for the growth of rtg-2, as, chinook salmon embryo (chse-214), and fathead minnow cells. cell yields ranged from 2 x 10 to 2.9 x 10 cells per ml, representing 7- to 10-fold increases over the initial cell conc ...198016345513
comparison of representative strains of infectious hematopoietic necrosis virus by serological neutralization and cross-protection assays.infectious hematopoietic necrosis virus (ihnv) is a pathogen of young salmon and trout. viral epizootics among these fish in private and public rearing facilities have been a problem in the northwestern united states from california to alaska, and an ihnv vaccine has been sought by the aquaculture experts. since an ihnv vaccine must be designed to immunize against all viral serotypes, an analysis of ihnv serotypes was made. a large number of viruses from widely separated geographic locations and ...199116348480
infectious pancreatic necrosis virus in atlantic salmon, salmo salar l., post-smolts in the shetland isles, scotland: virus identification, histopathology, immunohistochemistry and genetic comparison with scottish mainland isolates.during mid-june 1999 peak mortalities of 11% of the total stock per week were seen at a sea cage site of atlantic salmon, salmo salar l., post-smolts in the shetland isles, scotland. virus was isolated on chinook salmon embryo (chse) cells in a standard diagnostic test and infectious pancreatic necrosis virus (ipnv) identified by enzyme-linked immunosorbent assay. ipnv was confirmed as serogroup a by a cell immunofluorescent antibody test using the cross-reactive monoclonal antibody as-1. four w ...200616351696
in infectious pancreatic necrosis virus carrier atlantic salmon, salmo salar l., post-smolts, almost all kidney macrophages ex vivo contain a low level of non-replicating virus.the level of infection by infectious pancreatic necrosis virus (ipnv) of kidney macrophages from 12 asymptomatic carrier atlantic salmon post-smolts was studied. kidney leucocytes were fractionated on 34/51% percoll gradients, allowed to adhere to plastic wells overnight, washed to remove non-adherent cells and cultured for up to 7 days with or without renewal of medium on day 3. on day 1, supernatants were harvested, macrophages were counted, lysed and ipnv in the supernatants and lysates was t ...200616351697
toxicity to daphnia magna, hyalella azteca, oncorhynchus kisutch, oncorhynchus mykiss, oncorhynchus tshawytscha, and rana catesbeiana of atrazine, metolachlor, simazine, and their formulated products. 200616404660
assessing the accuracy of a polymerase chain reaction test for ichthyophonus hoferi in yukon river chinook salmon oncorhynchus tshawytscha.ichthyophonus hoferi plehn & mulsow, 1911, is a cosmopolitan, protistan pathogen of marine fishes. it is prevalent in mature returning chinook salmon oncorhynchus tshawytscha in the yukon river watershed, and may be associated with prespawning mortality. we developed and evaluated a polymerase chain reaction (pcr) test for i. hoferi using primers specific to the parasite's small subunit rdna. the test has a minimum detection limit of approximately 10(-5) parasite spores per reaction and does not ...200616532605
both msa genes in renibacterium salmoninarum are needed for full virulence in bacterial kidney disease.renibacterium salmoninarum, a gram-positive diplococcobacillus that causes bacterial kidney disease among salmon and trout, has two chromosomal loci encoding the major soluble antigen (msa) gene. because the msa protein is widely suspected to be an important virulence factor, we used insertion-duplication mutagenesis to generate disruptions of either the msa1 or msa2 gene. surprisingly, expression of msa protein in broth cultures appeared unaffected. however, the virulence of either mutant in ju ...200616597972
gonadotropin-releasing hormone activation of c-jun, but not early growth response factor-1, stimulates transcription of a luteinizing hormone beta-subunit gene.transcription of mammalian lh beta-subunit genes (lhbeta) is regulated by gnrh through activation of early growth response factor-1 (egr-1), which interacts synergistically with steroidogenic factor-1 (sf-1) and pituitary homeobox-1 (pitx1) at the promoter; egr-1 is thought to comprise the major mediator of this effect. however, the proximal promoters of lhbeta genes in lower vertebrates lack an egr-1 response element yet are responsive to gnrh; we demonstrate here that the promoter of the chino ...200616627584
salinity effects on activity and expression of glutathione s-transferases in white sturgeon and chinook salmon.this study evaluated the activity and expression of the glutathione s-transferase (gst) detoxification isoenzymes in juvenile white sturgeon (acipenser transmontanus) and chinook salmon (oncorhynchus tshawytscha) during acclimation from freshwater (2 per thousand) to estuarine (15 per thousand) salinity conditions. in white sturgeon, gst activity toward 1-chloro-2,4-dinitrobenzene (cdnb) increased significantly (p = 0.005; n = 5) with elevated salinity, but not for the chinook salmon (p = 0.174; ...200616677913
low levels of environmental ammonia increase susceptibility to disease in chinook salmon smolts.ammonia criteria are established using data from standardized toxicity tests involving healthy animals. both intrinsic and extrinsic environmental changes affect the immune system, but few toxicity studies consider the overall impact on this system and potential changes in resistance to infection. to investigate the effects of subacute levels of ammonia in coastal waters on physiological and immunological systems of fish, juvenile chinook salmon were maintained in seawater (10 degrees c, ph 7.8) ...200616826496
salmon, wildlife, and wine: marine-derived nutrients in human-dominated ecosystems of central california.pacific salmon transfer large quantities of marine-derived nutrients to adjacent forest ecosystems with profound effects on plant and wildlife production. we investigated this process for two highly modified california wine country rivers, one with consistent salmon runs (mokelumne river) and one without (calaveras river). mokelumne river chinook salmon transported biomass and n comparable to pacific northwest salmon streams. calaveras river levels were much less. scavenger numbers correlated wi ...200616826998
ultrastructural examination of the host inflammatory response within gills of netpen reared chinook salmon (oncorhynchus tshawytscha) with microsporidial gill disease.the sequence of host changes following the rupture of spore-laden xenomas of the microsporidian loma salmonae during microsporidial gill disease of salmon was deduced from ultrastructural examination of the gills of naturally infected, moribund, chinook salmon from a commercial aquaculture site. the gills contained many stages of parasite development suggesting fish were chronically exposed to the parasite. intact xenomas were generally found beneath the endothelium in arteries and arterioles an ...200716891122
detection and quantification of renibacterium salmoninarum dna in salmonid tissues by real-time quantitative polymerase chain reaction analysis.renibacterium salmoninarum is an important salmonid pathogen that is difficult to culture. we developed and assessed a real-time, quantitative, polymerase chain reaction (qpcr) assay for the detection and enumeration of r. salmoninarum. the qpcr is based on taqman technology and amplifies a 69-base pair (bp) region of the gene encoding the major soluble antigen (msa) of r. salmoninarum. the qpcr assay consistently detected as few as 5 r. salmoninarum cells per reaction in kidney tissue. the spec ...200616921877
contaminant exposure in outmigrant juvenile salmon from pacific northwest estuaries of the united better understand the dynamics of contaminant uptake in outmigrant juvenile salmon in the pacific northwest, concentrations of polychlorinated biphenyls (pcbs), ddts, polycylic aromatic hydrocarbons (pahs) and organochlorine pesticides were measured in tissues and prey of juvenile chinook and coho salmon from several estuaries and hatcheries in the us pacific northwest. pcbs, ddts, and pahs were found in tissues (whole bodies or bile) and stomach contents of chinook and coho salmon sampled fr ...200716957861
involvement of manayunkia speciosa (annelida: polychaeta: sabellidae) in the life cycle of parvicapsula minibicornis, a myxozoan parasite of pacific salmon.a coelomic myxozoan infection was detected in freshwater polychaetes, manayunkia speciosa from the klamath river, oregon/california, a site enzootic for the myxozoan parasites ceratomyxa shasta and parvicapsula minibicornis. the tetractinomyxon type actinospores had a near-spherical spore body 7.9 x 7.1 microm, with 3 spherical, protruding polar capsules, no valve cell processes, and a binucleate sporoplasm. parvicapsula minibicornis-specific primers parvi1f and parvi2r amplified dna from infect ...200616995391
pcbs, pcdd/fs, and organochlorine pesticides in farmed atlantic salmon from maine, eastern canada, and norway, and wild salmon from alaska.farmed atlantic salmon (salmo salar) from maine and eastern canada, wild alaskan chinook salmon (oncorhynchus tshawytscha), and organically farmed norwegian salmon samples were analyzed for the presence of polychlorinated biphenyls (pcbs), dioxin-like pcbs, polychlorinated dibenzo-p-dioxins (pcdds), dibenzo-p-furans (pcdfs), and chlorinated pesticides. pcdd and pcdf congeners were not detected in > 80% of the samples analyzed. total pcb concentrations (7.2-29.5 ng/g, wet weight, ww) in the farme ...200616999109
prevalence and analysis of renibacterium salmoninarum infection among juvenile chinook salmon oncorhynchus tshawytscha in north puget sound.renibacterium salmoninarum causes bacterial kidney disease (bkd), a chronic and sometimes fatal disease of salmon and trout that could lower fitness in populations with high prevalences of infection. prevalence of r. salmoninarum infection among juvenile chinook salmon oncorhynchus tshawytscha inhabiting neritic marine habitats in north puget sound, washington, usa, was assessed in 2002 and 2003. fish were collected by monthly surface trawl at 32 sites within 4 bays, and kidney infections were d ...200617058599
cardiovascular effects of native and non-native urotensin ii and urotensin ii-related peptide on rat and salmon hearts.urotensin ii (uii) was first discovered in the urophyses of goby fish and later identified in mammals, while urotensin ii-related peptide (urp) was recently isolated from rat brain. we studied the effects of uii on isolated heart preparations of chinook salmon and sprague-dawley rats. native rat uii caused potent and sustained, dose-dependent dilation of the coronary arteries in the rat, whereas non-native uii (human and trout uii) showed attenuated vasodilation. rat urp dilated rat coronary art ...200617097764
the marine pathogenic genotype of spironucleus barkhanus from farmed salmonids redescribed as spironucleus salmonicida n. sp.there are two genotypes of the diplomonad spironucleus barkhanus. based on sequence data from the small subunit ribosomal rna gene the conspecificity of these two genotypes has been questioned. therefore, we have sampled spironucleus from 27 fish, representing 14 populations, five species, and four genera. partial nucleotide sequences from the three genes; small subunit ribosomal dna, glutamate dehydrogenase 1 and alpha-tubulin were compared. the pathogenic isolates of s. barkhanus, which causes ...200617123418
aquatic francisella-like bacterium associated with mortality of intensively cultured hybrid striped bass morone chrysops x m. saxatilis.the present study identifies an emerging disease associated with an aquatic francisella-like bacterium that can cause mortality in hybrid striped bass morone chrysops x m. saxatilis reared intensively in freshwater. clinically affected fish were lethargic, had scattered haemorrhagic cutaneous lesions and diffuse gill pallor. the head kidney and spleen were markedly swollen and contained numerous interstitial granulomas; histological examination revealed small, pleomorphic gram-negative coccobaci ...200617140136
outbreaks of phaeohyphomycosis in the chinook salmon (oncorhynchus tshawytscha) caused by phoma herbarum.phoma herbarum has been associated with two outbreaks of systemic mycosis in hatchery-reared chinook salmon (oncorhynchus tshawytscha) fingerlings. affected fish exhibited abnormal swimming behavior, exophthalmia, multiple rounded areas of muscle softening, protruded hemorrhagic vents, and abdominal swelling. in all affected fish, swimbladders were filled with whitish creamy viscous fungal mass, surrounded by dark red areas in swimbladder walls, kidneys, and musculature. clinical and histopathol ...200717216330
assessment of environmental estrogens and the intersex/sex reversal capacity for chinook salmon (oncorhynchus tshawytscha) in primary and final municipal wastewater effluents.a trickling filter/solid contact (tf/sc) biological secondary treatment plant with chlorine disinfection serving a suburban population of 740,000 was assessed for environmental estrogens. weekly grab samples were taken at established sampling points and analyzed for various pertinent environmental estrogens including industrial chemicals, and natural and synthetic steroidal estrogens. additionally, human estrogen receptor (her) activity and capacity to elicit intersex/sex reversal for the wastew ...200717292961
a stochastic modelling approach to describing the dynamics of an experimental furunculosis epidemic in chinook salmon, oncorhynchus tshawytscha (walbaum).a susceptible-infected-removed (sir) stochastic model was compared to a susceptible-latent-infectious-removed (slir) stochastic model in terms of describing and capturing the variation observed in replicated experimental furunculosis epidemics, caused by aeromonas salmonicida. the epidemics had been created by releasing a single infectious fish into a group of susceptible fish (n = 43) and progress of the epidemic was observed for 10 days. this process was replicated in 70 independent groups. th ...200717298564
chronic administration of fluoxetine alters locomotor behavior, but does not potentiate the locomotor stimulating effects of crh in juvenile chinook salmon (oncorhynchus tshawytscha).the present study investigated: 1) the behavioral effects of chronic administration of a serotonin uptake inhibitor (fluoxetine) in juvenile chinook salmon, oncorhynchus tshawytscha and, 2) whether chronic administration of fluoxetine alters the behavioral effects of corticotropin-releasing hormone (crh). chronic (20 day) treatment with fluoxetine decreased locomotor activity when compared to fish given long-term injections of saline. an intracerebroventricular (i.c.v.) injection of crh had no e ...200717303457
flesh quality of market-size farmed and wild british columbia salmon.this study compared the flesh quality of farmed and wild sources of british columbia (bc) salmon with respect to concentrations of polychlorinated biphenyl compounds, polychlorinated dibenzodioxins/dibenzofurans and their associated toxic equivalents, total mercury (thg), methylmercury (mehg), and selected fatty acids of known importance for human health viz., omega-3 (n-3) highly unsaturated fatty acids (n-3 hufas) and (n-6) fatty acids. skinned fillets from known sources of farmed atlantic, co ...200717310704
cytopathic effects of chum salmon reovirus to salmonid epithelial, fibroblast and macrophage cell lines.the cytopathic effect (cpe) of chum salmon reovirus (csv), an aquareovirus, was studied in three salmonid cell lines: epithelial-like chse-214 from chinook salmon embryo, fibroblast-like rtg-2, and monocyte/macrophage-like rts11, both from rainbow trout. chse-214 and rtg-2 supported syncytia formation with more dramatic syncytia being observed in chse-214 cultures, while csv induced homotypic aggregation (ha) in rts11. syncytia and ha formation were blocked by cycloheximide and ribavirin but not ...200717391795
distribution and habitat characteristics of manayunkia speciosa and infection prevalence with the parasite ceratomyxa shasta in the klamath river, oregon-california.a survey for manayunkia speciosa, the freshwater polychaete host for the myxozoan parasite ceratomyxa shasta, was conducted from 2003 to 2005 as part of an integrated study of the epizootiology of ceratomyxosis in klamath river salmonids. substrata samples (n = 257) were collected in a variety of habitats from klamath lake to the mouth of the klamath river to document occurrence and relative abundance of the polychaete by habitat type and to estimate the prevalence of c. shasta within selected p ...200717436945
pesticide and pathogen: heat shock protein expression and acetylcholinesterase inhibition in juvenile chinook salmon in response to multiple stressors.rapid expression of heat shock protein (hsp) families in response to a variety of stressors has been demonstrated in many organisms, including fish. the present 60-d challenge study was designed to compare hsp induction in juvenile chinook salmon following exposure to individual pesticides, virus, and both stressors combined. heat shock protein expression patterns over time were monitored and related to the extent of virus infection and mortality. acetylcholinesterase (ache) inhibition and recov ...200717571690
detection of the intranuclear microsporidium nucleospora salmonis in naturally and experimentally exposed chinook salmon oncorhynchus tshawytscha by in situ hybridization.nucleospora salmonis, an intranuclear microsporidian parasite of salmonid fish, is often difficult to observe in histological sections or wet mount preparations from lightly infected tissues because of its small size and location within the nuclei of lymphoblast-type cells. diagnosis of infections by conventional light microscopy is directly dependent upon distinguishing different stages of the parasite from host cell nuclear material or vacuoles. to assist detection of stages of the parasite in ...200717605006
pacific salmon extinctions: quantifying lost and remaining diversity.widespread population extirpations and the consequent loss of ecological, genetic, and life-history diversity can lead to extinction of evolutionarily significant units (esus) and species. we attempted to systematically enumerate extinct pacific salmon populations and characterize lost ecological, life history, and genetic diversity types among six species of pacific salmon (chinook [oncorhynchus tshawytscha], sockeye [o. nerka], coho [o. kisutch], chum [o. keta], and pink salmon [o. gorbuscha] ...200717650251
eco-evolutionary vs. habitat contributions to invasion in salmon: experimental evaluation in the wild.although trait evolution over contemporary timescales is well documented, its influence on ecological dynamics in the wild has received much less attention particularly compared to traditional ecological and environmental factors. for example, evolution over ecologically relevant timescales is expected in populations that colonize new habitats, where it should theoretically enhance fitness, associated vital rates of survival and reproduction, and population growth potential. nonetheless, success ...200817908221
genotypes and phylogeographical relationships of infectious hematopoietic necrosis virus in california, usa.infectious hematopoietic necrosis virus (ihnv) contains 3 major genogroups in north america with discreet geographic ranges designated as upper (u), middle (m), and lower (l). a comprehensive genotyping of 237 ihnv isolates from hatchery and wild salmonids in california revealed 25 different sequence types (a to y) all in the l genogroup; specifically, the genogroup contained 14 sequence types that were unique to individual isolates as well as 11 sequence types representing 2 or more identical i ...200717933395
candidate loci reveal genetic differentiation between temporally divergent migratory runs of chinook salmon (oncorhynchus tshawytscha).local adaptation is a dynamic process driven by selection that can vary both in space and time. one important temporal adaptation for migratory animals is the time at which individuals return to breeding sites. chinook salmon (oncorhynchus tshawytscha) are excellent subjects for studying the genetic basis of temporal adaptation because their high seasonal homing fidelity promotes reproductive isolation leading to the formation of local populations across diverse environments. we tested for adapt ...200717971087
use of elisa to monitor bacterial kidney disease in naturally spawning chinook salmon.bacterial kidney disease (bkd) caused by renibacterium salmoninarum (rs) is a serious problem among pacific northwest salmon hatcheries and has raised concerns that salmon reared in hatcheries may spread bkd to natural populations. in order to monitor the potential spread of this disease to salmon spawning in nature, a method must be available to collect and analyze tissues from naturally spawning salmon. kidney tissue analyzed by enzyme-linked immunosorbent assay (elisa) is the standard method ...200717972755
quantitative threat analysis for management of an imperiled species: chinook salmon (oncorhynchus tshawytscha).chinook salmon (oncorhynchus tshawytscha) have declined dramatically across the pacific northwest because of multiple human impacts colloquially characterized as the four "h's": habitat degradation, harvest, hydroelectric and other dams, and hatchery production. we use this conceptual framework to quantify the relative importance of major threats to the current status of 201 chinook populations. current status is characterized by two demographic indices: population density and trend. we employ p ...200717974341
can the surface immobilization antigens of philasterides dicentrarchi (ciliophora: scuticociliatida) be used as target antigens to develop vaccines in cultured fish?in order to test whether immobilization antigens (i-antigens) of philasterides dicentrarchi could be suitable antigenic targets against scuticociliatosis, polyclonal olive flounder (paralichthys olivaceus) sera were raised against p. dicentrarchi by immunization with lysates of ciliates grown using chinook salmon epithelial (chse) cells, and the ability of the immune sera to kill the ciliates via classical complement pathway was analyzed in relation to agglutination activity. the immune sera sho ...200818023208
radiation-induced adaptive response in fish cell lines.there is considerable interest at present in low-dose radiation effects in non-human species. in this study gamma radiation-induced adaptive response, a low-dose radiation effect, was examined in three fish cell lines, (chse-214 (chinook salmon), rtg-2 (rainbow trout) and zeb-2j (zebrafish)). cell survival after exposure to direct radiation with or without a 0.1 gy priming dose, was determined using the colony forming assay for each cell line. additionally, the occurrence of a bystander effect w ...200818054128
the atlantic salmon z-dna binding protein kinase phosphorylates translation initiation factor 2 alpha and constitutes a unique orthologue to the mammalian dsrna-activated protein kinase r.the translation initiation factor 2 alpha (eif2alpha)-kinase, dsrna-activated protein kinase (pkr), constitutes one of the major antiviral proteins activated by viral infection of vertebrates. pkr is activated by viral double-stranded rna and subsequently phosphorylates the alpha-subunit of translation initiation factor eif2. this results in overall down regulation of protein synthesis in the cell and inhibition of viral replication. fish appear to have a pkr-like protein that has z-dna binding ...200818076653
bacterial dna indicated as an important inducer of fish cathelicidins.cathelicidins are antimicrobial peptides indicated as important in the control of the natural microflora as well as in the fight against bacterial invasion in mammals. little is known about cathelicidins in fish and here the chinook salmon (oncorhynchus tshawytscha) embryo cell line (chse-214) was used as a model system to study the expression of cathelicidins due to fish pathogenic bacteria. the cdna of cathelicidin from chse-214 cells (cscath) was cloned and shown to be closely related to gene ...200818164061
binding of infectious pancreatic necrosis virus (ipnv) to membrane proteins from different fish cell lines.the early interactions between infectious pancreatic necrosis virus (ipnv) from atlantic salmon and susceptible cell lines were studied using a virus overlay protein binding assay (vopba). membrane preparations from four different cell lines, bluegill fry (bf)-2 cells, chinook salmon embryo (chse)-214 cells, salmon head kidney (shk)-1 cells and atlantic salmon kidney (ask) cells were separated by sds-page, blotted to nitrocellulose membranes and incubated with either a highly virulent ipnv field ...200818175041
longevity of ceratomyxa shasta and parvicapsula minibicornis actinospore infectivity in the klamath river.infectious ceratomyxa shasta and parvicapsula minibicornis actinospores were present in klamath river samples collected in april, may, and june 2005. juvenile chinook salmon oncorhynchus tshawytscha exposed to river water maintained at the ambient klamath river temperature for 0, 4, 24, 72, and 168 h (7 d) developed asymptomatic infections from both parasites. elevated water temperature (18 degrees c) in june may have reduced actinospore viability, as both c. shasta and p. minibicornis infection ...200718201047
mercury and other trace elements in farmed and wild salmon from british columbia, canada.the present study reports measured levels of hg and other trace elements in commercial salmon feed; farmed atlantic, coho, and chinook salmon (n = 110); and wild coho, chinook, chum, sockeye, and pink salmon (n = 91). metal concentrations in farmed and wild salmon from british columbia, canada, were relatively low and below human health consumption guidelines. methylmercury in all salmon samples (range, 0.03-0.1 microg/g wet wt) were below the 0.5 microg/g guideline set by health canada. negligi ...200818211126
sortase inhibitor phenyl vinyl sulfone inhibits renibacterium salmoninarum adherence and invasion of host cells.renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fishes, is a gram-positive diplococcobacillus belonging to the family micrococcaceae. analysis of the genome sequence of the bacterium demonstrated the presence of a sortase homolog (srtd), a gene specifying an enzyme found in gram-positive bacteria and required for covalent anchoring of cell surface proteins. interference of sortase activity is being examined as a target for therapeutic prevention of infecti ...200718286808
polybrominated diphenyl ethers (pbdes) in farmed and wild salmon marketed in the northeastern united states.recently, we reported on the analysis of polychlorinated biphenyls (pcbs) and chlorinated pesticides in farmed atlantic salmon (salmo salar) from maine, eastern canada, and norway, and wild alaskan chinook salmon (oncorhynchus tshawytscha). in this paper, we extend the analysis to polybrominated diphenyl ethers (pbdes) in these samples. total pbde concentrations in the farmed salmon (0.4-1.4ng/g, wet weight, ww) were not significantly different from those in the wild alaskan chinook samples (0.4 ...200818313722
biological characterisation of a recombinant atlantic salmon type i interferon synthesized in escherichia coli.type i (alpha/beta) interferons (ifns) are a family of cytokines that stimulate the expression of numerous proteins that mediate an antiviral state in uninfected cells. two atlantic salmon (salmo salar) ifn-alpha (sasaifn-alpha1 & 2) genes have previously been cloned and both were found to contain a putative n-linked glycosylation site. recombinant sasaifn-alpha1 (rsasaifn-alpha1) produced in eukaryotic systems has repeatedly been shown to confer antiviral properties. however, different ifn-alph ...200818329900
genetic diversity of infectious hematopoietic necrosis virus from feather river and lake oroville, california, and virulence of selected isolates for chinook salmon and rainbow trout.infectious hematopoietic necrosis virus (ihnv) is a significant pathogen of young salmonid fishes worldwide but particularly within the historical range of the pacific northwest and california. in the sacramento and san joaquin river drainages of california, ihnv outbreaks in juvenile chinook salmon oncorhynchus tshawytscha have been observed regularly at large production hatcheries, including coleman national fish hatchery (established in 1941) and feather river state fish hatchery (frh; establ ...200718333482
effects of dexamethasone on host innate and adaptive immune responses and parasite development in rainbow trout oncorhynchus mykiss infected with loma salmonae.the effects of dexamethasone (dex) treatment on infections with the microsporidian parasite, loma salmonae and the effects of dex on initiation of the adaptive immune response were investigated in rainbow trout, oncorhynchus mykiss experimentally infected with the parasite. dex treatment resulted in significantly higher infections with the parasite in the gills and other internal organs, suggesting that dex inhibits aspects of the innate immune response to l. salmonae; the heavier infections in ...200818359641
novel fugu u6 promoter driven shrna expression vector for efficient vector based rnai in fish cell fish species, although many studies on the use of rna interference (rnai) for gene function analysis have been reported, almost of them have utilized in vitro transcribed or synthesized small interfering rna (sirna), and there are a few studies which examined vector based rnai in fish species. in this study, we have identified u6 promoter of fugu (takifugu rubripes), and utilized it for expression of short hairpin rna (shrna) in fish cell lines. using northern blot analysis, we confirmed succ ...200818452704
expression of an adenovirus encoded reporter gene and its reactivation following uvc and oxidative damage in cultured fish cells.recombinant human adenovirus, adca35lacz, was used to examine expression of a reporter gene and its reactivation following uvc (200-280 nm) and oxidative damage in fish cells.200818470745
effect of processing conditions on trace elements in fish roe from six commercial new zealand fish species.the concentrations of trace elements in fish roes and the effect of processing conditions (karasumi-like or karashi mentaiko) were investigated in six commercial fish species from new zealand. the studied elements were as, cd, cr, cu, hg, pb, and zn, and the roes were from the following species: chinook salmon ( oncorhynchus tshawytscha), hoki ( macruronus novaezelandiae), southern blue whiting ( micromesistius australis), hake ( merluccius australis), blue warehou ( seriolella brama), and barra ...200818494479
monte carlo inference for state-space models of wild animal populations.summary: we compare two monte carlo (mc) procedures, sequential importance sampling (sis) and markov chain monte carlo (mcmc), for making bayesian inferences about the unknown states and parameters of state-space models for animal populations. the procedures were applied to both simulated and real pup count data for the british grey seal metapopulation, as well as to simulated data for a chinook salmon population. the mcmc implementation was based on tailor-made proposal distributions combined w ...200918565166
distribution of marine birnavirus in cultured olive flounder paralichthys olivaceus in korea.surveys of marine birnavirus (mabv) were undertaken in cultured olive flounder paralichthys olivaceus from the south and west coastal areas and jeju in korea during the period january 1999 to april 2007. mabv was detected in all seasons from the fry, juveniles and adult fish from the areas examined. evident cytopathic effects of the virus including rounding and cell lysis were observed in chinook salmon embryo (chse-214) and rainbow trout gonad (rtg-2) cells, but not in fathead minnow (fhm) and ...200818604495
impacts of low-dose gamma-radiation on genotoxic risk in aquatic ecosystems.chinook salmon cells were exposed to gamma radiation and chromosome damage was assessed using the micronucleus assay. the salmon cells were resistant to radiation at all doses compared to human and mammalian cells. we used an indirect approach to determine if prior low dose exposures at environmental dose levels might alter the consequences of radiation exposures to high doses of radiation (adaptive response). the cells adapted but only at doses which were above levels that might be expected env ...200718648569
lost in the zygote: the dilution of paternal mtdna upon fertilization.the mechanisms by which paternal inheritance of mitochondrial dna (mtdna) (paternal leakage) and, subsequently, recombination of mtdna are prevented vary in a species-specific manner with one mechanism in common: paternally derived mtdna is assumed to be vastly outnumbered by maternal mtdna in the zygote. to date, this dilution effect has only been described for two mammalian species, human and mouse. here, we estimate the mtdna content of chinook salmon oocytes to evaluate the dilution effect o ...200818685570
expression of immune-regulatory genes in juvenile chinook salmon following exposure to pesticides and infectious hematopoietic necrosis virus (ihnv).impairment of fish immune function as a consequence of polluted aquatic environments can result in changes in susceptibility to disease. in this study, we investigated the effects of two widely used insecticides, chlorpyrifos (cp) and esfenvalerate (ev), and a pathogen, infectious hematopoietic necrosis virus (ihnv), singly and in combination, on survival and cytokine (mx protein, il-1beta, tgf-beta and igf-1) expression in juvenile chinook salmon. fish were exposed for 96 h to sublethal concent ...200818691654
an immune-complex glomerulonephritis of chinook salmon, oncorhynchus tshawytscha (walbaum).chinook salmon from new zealand were shown to have a generalized membranous glomerulonephritis that was most severe in large fish. marked thickening of the glomerular basement membrane was the most consistent lesion, with the presence of an electron-dense deposit beneath the capillary endothelium.severely affected glomeruli also had expansion of the mesangium and loss of capillaries,synechiae of the visceral and parietal epithelium and mild fibrosis of bowmans capsule. chinook salmon from britis ...200818752546
the molecular regulation of chinook salmon gonadotropin beta-subunit gene transcription.expression of the gonadotropin beta-subunit genes is tightly regulated both cell-specifically and by the regulatory hormones to achieve the appropriate gonadotropic hormone levels required for reproductive development and function. although the cdna sequences of these genes are highly conserved across species, their promoter sequences are not and few functional studies have been carried out to understand the molecular mechanisms through which their expression is regulated. we and others have car ...200918789942
genes associated with an effective host response by chinook salmon to renibacterium effective host response to renibacterium salmoninarum, the etiologic agent of bacterial kidney disease, is poorly characterized. using suppression subtractive hybridization, we exploited the difference in early host response in the pronephros of fish challenged by an attenuated strain (mt239) or a virulent strain (atcc 33209) of r. salmoninarum. among the 132 expressed sequence tag (est) clones that were sequenced, 20 were selected for expression analysis at 24 and 72h after challenge. ests m ...200918793667
the effects of water velocity on the ceratomyxa shasta infectious cycle.ceratomyxa shasta is a myxozoan parasite identified as a contributor to salmon mortality in the klamath river, usa. the parasite has a complex life cycle involving a freshwater polychaete, manayunkia speciosa and a salmonid. as part of ongoing research on how environmental parameters influence parasite establishment and replication, we designed a laboratory experiment to examine the effect of water flow (velocity) on completion of the c. shasta infectious cycle. the experiment tested the effect ...200918803584
characterization of renibacterium salmoninarum with reduced susceptibility to macrolide antibiotics by a standardized antibiotic susceptibility test.three cohorts of juvenile and subadult chinook salmon oncorhynchus tshawytscha received multiple treatments with macrolide antibiotics for bacterial kidney disease (bkd) during rearing in a captive broodstock program. a total of 77 mortalities among the cohorts were screened for renibacterium salmoninarum, the etiologic agent of bkd, by agar culture from kidney, and isolates from 7 fish were suitable for growth testing in the presence of macrolide antibiotics. the minimum inhibitory concentratio ...200818814542
characterization of rainbow trout cell lines using microsatellite dna profiling.ten microsatellite loci (omy27du,omy325(a3)uog, omyfgt5tuf,omyfgt14tuf, omyfgt15tuf,omyfgt23tuf, omy77du,ssa20.19nuig, ots1bml, andone18asc) were amplified using the polymerase chain reaction to create genetic profiles for nine cell lines (rtg-2, rth-149,rtl-w1,rtgill-w1, rts-11, rts-34st, rtp-2, rtp-91e and rtp-91f) from rainbow trout(oncorhynchus mykiss) and one cell line (chse-214) from chinook salmon (o. tschawytscha). a cell line (phl) from anon-salmonid, the pacific herring (clupea harengu ...200119002917
oxygen consumption and blood flow distribution in perfused skeletal muscle of chinook isolated, perfused salmon tail preparation showed oxyconformance at low oxygen delivery rates. addition of pig red blood cells to the perfusing solution at a haematocrit of 5 or 10% allowed the tail tissues to oxyregulate. below ca. 60 ml o(2) kg(-1) h(-1) of oxygen delivery (do(2)), vo(2) was delivery dependent. above this value additional oxygen delivery did not increase vo(2) of resting muscle above ca. 35 ml o(2) kg(-1) h(-1). following electrical stimulation, vo(2) increased to ca. 65 ml ...200919066910
molecular and morphological analysis of myxobolus spp. of salmonid fishes with the description of a new myxobolus species.while investigating the parasite fauna of wild coho salmon. oncorhynchus kisutch (walbaum, 1792), histological examination provided evidence of a new species of myxobolus (myxozoa: myxosporea) infecting nerves of skeletal muscle. spores were morphologically similar to those of the intramuscular myxobolus insidiosus wyatt and pratt, 1963, both having pyriform spores with clavate polar capsules. however, the former developed exclusively in the nerves of skeletal muscle rather than in myocytes. we ...200819127969
spillway-induced salmon head injury triggers the generation of brain alphaii-spectrin breakdown product biomarkers similar to mammalian traumatic brain injury.recent advances in biomedical research have resulted in the development of specific biomarkers for diagnostic testing of disease condition or physiological risk. of specific interest are alphaii-spectrin breakdown products (sbdps), which are produced by proteolytic events in traumatic brain injury and have been used as biomarkers to predict the severity of injury in humans and other mammalian brain injury models. this study describes and demonstrates the successful use of antibody-based mammalia ...200919214235
cultural characteristics of salmonid alphaviruses--influence of cell line and temperature.laboratory studies were carried out to investigate the cultural characteristics of salmonid alphaviruses (sav) from atlantic salmon (as, salmo salar) and rainbow trout (rt, oncorhynchus mykiss), particularly in relation to cell line and temperature. in an initial study, sav was isolated from 12 viraemic sera and passaged in chinook salmon embryo (chse-214) cells at 15 degrees c. geometric mean titres (gmt) after initial isolation were found to be significantly higher (p < 0.05) relative to those ...200819238759
sea lice, lepeophtheirus salmonis, transfer between wild sympatric adult and juvenile salmon on the north coast of british columbia, canada.we examine sea lice, lepeophtheirus salmonis, on juvenile and adult salmon from the north coast of british columbia between 2004 and 2006 in an area that does not at present contain salmon farms. there is a pronounced zonation in the abundance of l. salmonis on juvenile pink salmon, oncorhynchus gorbuscha, in the skeena and nass estuaries. abundances in the proximal and distal zones of these estuaries are 0.01 and 0.05 respectively. the outer zones serve as feeding and staging areas for the pink ...200919245630
development and validation of a quantitative pcr to detect parvicapsula minibicornis and comparison to histologically ranked infection of juvenile chinook salmon, oncorhynchus tshawytscha (walbaum), from the klamath river, usa.parvicapsula minibicornis is a myxosporean parasite that is associated with disease in pacific salmon during their freshwater life history phase. this study reports the development of a quantitative (real-time) polymerase chain reaction (qpcr) to detect p. minibicornis dna. the qpcr assay targets the 18s ribosomal subunit gene. a plasmid dna control was developed to calibrate cycle threshold (c(t)) score to plasmid molecular equivalent (pme) units, a measure of gene copy number. assay validation ...200919261045
decreased mortality of lake michigan chinook salmon after bacterial kidney disease challenge: evidence for pathogen-driven selection?in the late 1960s, chinook salmon oncorhynchus tshawytscha from the green river, washington, were successfully introduced into lake michigan. during spring from 1988 to 1992, large fish die-offs affecting chinook salmon occurred in the lake. multiple ecological factors probably contributed to the severity of the fish kills, but the only disease agent found regularly was renibacterium salmoninarum, the causative agent of bacterial kidney disease. in this study, survival after challenge by r. salm ...200819306612
in vitro hepatic metabolism of 2,2',4,4',5-pentabromodiphenyl ether (bde 99) in chinook salmon (onchorhynchus tshawytscha).polybrominated diphenyl ethers (pbdes) are brominated flame retardants that persist in the environment and are present in geographically widespread fish species. pbde concentrations can be particularly high in resident chinook salmon (onchorhynchus tshawytscha) in the puget sound, washington. although pbde residues in salmon and other fish are often dominated by lower brominated congeners, these congeners are not produced commercially in the greatest quantity, suggesting bioaccumulation of the l ...200919346012
modeling fish health to inform research and management: renibacterium salmoninarum dynamics in lake michigan.little is known about the interaction between fish pathogens and managed freshwater fish populations. we develop a model of chinook salmon (oncorhynchus tschawytscha)-renibacterium salmoninarum (rs) dynamics based on free-swimming lake michigan fish by synthesizing population and epidemiological theory. using the model, we expose critical uncertainties about the system, identify opportunities for efficient and insightful data collection, and pose testable hypotheses. our simulation results sugge ...200919425436
the winter ulcer bacterium moritella viscosa demonstrates adhesion and cytotoxicity in a fish cell model.moritella viscosa is considered the main aetiological agent of 'winter ulcer' disease in farmed salmonid fish. to further understand the pathogenesis of this disease, m. viscosa interaction with fish cells was studied using a chinook salmon embryo cell line (chse-214). as winter ulcer appears exclusively at temperatures below 7-8 degrees c, we attempted to identify if this connection is explained by temperature regulated bacterial virulence. therefore, infection studies were performed at a tempe ...200919539022
effects of temperature on disease progression and swimming stamina in ichthyophonus-infected rainbow trout, oncorhynchus mykiss (walbaum).rainbow trout, oncorhynchus mykiss, were infected with ichthyophonus sp. and held at 10 degrees c, 15 degrees c and 20 degrees c for 28 days to monitor mortality and disease progression. infected fish demonstrated more rapid onset of disease, higher parasite load, more severe host tissue reaction and reduced mean-day-to-death at higher temperature. in a second experiment, ichthyophonus-infected fish were reared at 15 degrees c for 16 weeks then subjected to forced swimming at 10 degrees c, 15 de ...200919570061
reference genes evaluated for use in infectious pancreatic necrosis virus real-time rt-qpcr assay applied during different stages of an infection.the stability of 6 reference genes, 18s, beta-actin, rps20, eef1alpha, g6pdh and gapdh, was examined in tissues from atlantic salmon (salmo salar) and chinook salmon embryo cells (chse-214). the main objective of this study was to determine the most suitable reference genes for use for the normalisation of data in quantitative real-time rt-qpcr assays conducted on infected tissues. the tissue samples selected for analysis were taken from head kidney and pylorus and collected at different time po ...200919638286
transcriptional differences between triploid and diploid chinook salmon (oncorhynchus tshawytscha) during live vibrio anguillarum challenge.understanding how organisms function at the level of gene expression is becoming increasingly important for both ecological and evolutionary studies. it is evident that the diversity and complexity of organisms are not dependent solely on their number of genes, but also the variability in gene expression and gene interactions. furthermore, slight differences in transcription control can fundamentally affect the fitness of the organism in a variable environment or during development. in this stud ...201019707232
gene expression profiling and environmental contaminant assessment of migrating pacific salmon in the fraser river watershed of british columbia.the health and physiological condition of anadromous salmon is of concern as their upriver migration requires navigation of human-impacted waterways and metabolism of stored energy reserves containing anthropogenic contaminants. such factors may affect reproductive success of fish stocks. this study investigates chemical contaminant burdens and select gene expression profiles in pacific sockeye (oncorhynchus nerka) and chinook (oncorhynchus tshawytscha) salmon which traverse the fraser river wat ...201019811841
the visual systems of euryhaline fishes.1. the retinas of all marine fishes so far examined except the labridae, and of all terrestrial vertebrates contain the rhodopsin system alone; those of fresh water fishes the porphyropsin system alone. in the present paper the visual systems of a number of euryhaline fishes are examined-fishes capable of existence in a wide range of salinities, though usually restricted in spawning either to the sea (catadromous) or to fresh water (anadromous). 2. the retinas of the anadromous salmonids (brook ...194119873269
in vitro markers for virulence in yersinia this study, different traits that have been associated with bacterial virulence were studied in yersinia ruckeri. two isolates that had been shown to cause disease and mortality in experimentally infected rainbow trout were compared with five avirulent isolates. both virulent isolates showed high adhesion to gill and intestinal mucus of rainbow trout, whereas the majority of non-virulent strains demonstrated significantly lower adhesion. a decrease in adherence capability following bacterial ...201019878528
disparate infection patterns of ceratomyxa shasta (myxozoa) in rainbow trout (oncorhynchus mykiss) and chinook salmon (oncorhynchus tshawytscha) correlate with internal transcribed spacer-1 sequence variation in the parasite.ceratomyxa shasta is a virulent myxosporean parasite of salmon and trout in the pacific northwest of north america. the parasite is endemic in the klamath river, oregon/california, where a series of dams prevent movement of fish hosts between the upper and lower parts of the basin. ceratomyxa shasta exhibits a range of infection patterns in different fish species above and below the dams. we hypothesised that the variations in infection and disease are indicators that different strains of the pa ...201019895812
effects of ceratomyxa shasta dose on a susceptible strain of rainbow trout and comparatively resistant chinook and coho salmon.ceratomyxa shasta infects salmon and trout, causing ceratomyxosis, a disease characterized by parasite proliferation in the intestine and death. we used laboratory challenges to investigate the infective dose for 3 fish species: a susceptible strain of rainbow trout oncorhynchus mykiss and comparatively resistant chinook o. tshawytscha and coho salmon o. kisutch. for susceptible rainbow trout, we determined the outcome of infection under conditions of varying parasite dose, fish size, and parasi ...200919899347
differentially expressed genes following persistent infection with infectious pancreatic necrosis virus in vitro and in vivo.the mechanisms of viral persistence of infectious pancreatic necrosis virus (ipnv) are not well understood. in this study we have used a model of ipnv persistently infected chse (chinook salmon embryonic) cells as correlate of persistent infection in fish focusing on differentially expressed genes using subtractive hybridization (ssh). selected genes were also analyzed by quantitative real-time pcr (qpcr) in persistently infected parr of atlantic salmon. persistent infection was established by g ...201020152904
disease susceptibility of salmon exposed to polybrominated diphenyl ethers (pbdes).the health effects of the flame retardant polybrominated diphenyl ethers (pbdes) in fish are not well understood. to determine the potential effects of this ubiquitous contaminant class on fish health, juvenile subyearling chinook salmon (oncorhynchus tshawytscha) were fed a diet that reflected the pbde congeners found in the stomach contents of subyearling chinook salmon collected from the highly urbanized and industrialized lower willamette river in the columbia river basin of north america. t ...201020207027
invasion of ceratomyxa shasta (myxozoa) and comparison of migration to the intestine between susceptible and resistant fish hosts.the myxozoan parasite ceratomyxa shasta infects salmonids causing ceratomyxosis, a disease elicited by proliferation of the parasite in the intestine. this parasite is endemic to the pacific northwest of north america and salmon and trout strains from endemic river basins show increased resistance to the parasite. it has been suggested that these resistant fish (i) exclude the parasite at the site of invasion and/or (ii) prevent establishment in the intestine. using parasites pre-labeled with a ...201020385137
the amino terminus of the salmonid alphavirus capsid protein determines subcellular localization and inhibits cellular proliferation.salmonid alphavirus (sav) is the most divergent member of the family togaviridae and constitutes a threat to farming of salmonid fish in europe. here, we report cloning, expression and preliminary functional analysis of the capsid protein of sav, confirming it to be expressed as an approximately 31-kda protein in infected cells. the protein localizes strictly to the cytoplasm in chinook salmon embryo cells, and either to the nucleus or cytoplasm in bluegill fry cells. an expression study of full ...201020556445
pathological and immunological responses associated with differential survival of chinook salmon following renibacterium salmoninarum challenge.chinook salmon oncorhynchus tshawytscha are highly susceptible to renibacterium salmoninarum, the causative agent of bacterial kidney disease (bkd). previously we demonstrated that introduced chinook salmon from lake michigan, wisconsin (wi), usa, have higher survival following r. salmoninarum challenge relative to the progenitor stock from green river, washington, usa. in the present study, we investigated the pathological and immunological responses that are associated with differential surviv ...201020597428
Displaying items 201 - 300 of 397