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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 states.to 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
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 lines.in 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 salmoninarum.an 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 salmon.an 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
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
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
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
in vitro markers for virulence in yersinia ruckeri.in 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
spatial, temporal and host factors structure the ceratomyxa shasta (myxozoa) population in the klamath river basin.the myxozoan parasite ceratomyxa shasta is a virulent pathogen of salmonid fish in the klamath river, oregon/california, usa. we previously defined four principal genotypes of the parasite (o, i, ii, iii) based on a trinucleotide repeat (atc)(0-3) in internal transcribed spacer region 1 sequences. genotypes occur in sympatry and show marked host preference: i in chinook salmon (oncorhynchus tschawytscha) and ii in non-native rainbow trout (o. mykiss). in the present study, we sequenced the paras ...201020601174
color photographic index of fall chinook salmon embryonic development and accumulated thermal units.knowledge of the relationship between accumulated thermal units and developmental stages of chinook salmon embryos can be used to determine the approximate date of egg fertilization in natural redds, thus providing insight into oviposition timing of wild salmonids. however, few studies have documented time to different developmental stages of embryonic chinook salmon and no reference color photographs are available. the objectives of this study were to construct an index relating developmental s ...201020686709
[incomplete congruence between morphobiological characters and sex-specific molecular markers in pacific salmons: 1. analysis of discrepancy in five species of the genus oncorhynchus].the congruence between molecular markers, identifying the presence of the y chromosome, and secondary sexual characters was examined in asian populations of five pacific salmon species: pink salmon (oncorhynchus gorbuscha), chum salmon (o. keta), sockeye salmon (o. nerka), chinook salmon (o. tschawytsha), and sima (o. masou). it was demonstrated that in all species examined, the presence or absence of sex-specific molecular markers was to a considerable degree congruent with secondary sexual cha ...201020795502
development of infectious cdna clones of salmonid alphavirus subtype 3.abstract:201020858233
antiviral function of tilapia hepcidin 1-5 and its modulation of immune-related gene expressions against infectious pancreatic necrosis virus (ipnv) in chinook salmon embryo (chse)-214 cells.antimicrobial peptides, small cysteine-rich molecules, play vital roles in host defense mechanisms against pathogen infection. recently, tilapia hepcidin (th)1-5, was characterized, and its antimicrobial functions against several pathogens were reported. herein, we investigated the antiviral functions of th1-5 against infectious pancreatic necrosis virus (ipnv) in chinook salmon embryo (chse)-214 cells. the presence of th1-5 enhanced the survival of chse-214 cells infected with ipnv. additionall ...201020863896
potential of the melanophore pigment response for detection of bacterial toxicity.chromatophore cells have been investigated as potential biodetectors for function-based detection of chemically and biologically toxic substances. oncorhynchus tshawytscha (chinook salmon) melanophores, a chromatophore cell type containing brown pigment, rapidly detect the salmonid pathogens aeromonas salmonicida, yersinia ruckeri, and flavobacterium psychrophilum and the human pathogen bacillus cereus.201020952639
basis of acoustic discrimination of chinook salmon from other salmons by echolocating orcinus orca.the "resident" ecotype of killer whales (orcinus orca) in the waters of british columbia and washington state have a strong preference for chinook salmon even in months when chinook comprise less than about 10% of the salmon population. the foraging behavior of killer whales suggests that they depend on echolocation to detect and recognize their prey. in order to determine possible cues in echoes from salmon species, a series of backscatter measurements were made at the applied physics laborator ...201020968392
simulating fishery-induced evolution in chinook salmon: the role of gear, location, and genetic correlation among traits.adaptation to human-modified ecosystems has been implicated in changing the life history of a number of wild animal populations, potentially contributing to their collapse. fishing may be an important evolutionary force that can change the distribution of fitness-related traits; however, the magnitude and direction of the evolutionary response may be influenced by different management strategies. most phenotypic traits subject to human-induced selection are simultaneously influenced by the envir ...201021049881
mortality threshold for juvenile chinook salmon oncorhynchus tshawytscha in an epidemiological model of ceratomyxa shasta.the myxozoan parasite ceratomyxa shasta is a significant pathogen of juvenile chinook salmon oncorhynchus tshawytscha in the klamath river, california, usa. this parasite requires 2 hosts to complete its life cycle: a freshwater polychaete (manayunkia speciosa) and a salmonid. the complex life cycle and large geographic area where infection occurs make it difficult to monitor and manage ceratomyxosis. we present a model for ceratomyxosis-induced mortality in o. tshawytscha, from which parameters ...201021290897
surface properties of streptococcus phocae strains isolated from diseased atlantic salmon, salmo salar l.streptococcus phocae is an emerging pathogen for chilean atlantic salmon, salmo salar, but the factors determining its virulence are not yet elucidated. in this work, cell surface-related properties such as hydrophobicity and haemagglutination, adhesion to mucus and cell lines, capsule detection, survival and biofilm formation in skin mucus and serum resistance of the isolates responsible for outbreaks in atlantic salmon and seals were examined. adhesion to hydrocarbons and the results of salt a ...201121306587
residues of pbdes in northeastern pacific marine fish: evidence for spatial and temporal trends.in the flesh (skinless fillet) of chinook, chum, coho, pink, and sockeye salmon (oncorhynchus tshawytscha, o. keta, o. kisutch, o. gorbuscha, and o. nerka, respectively), sablefish (anoplopoma fimbria) and walleye pollock (theragra chalcogramma) from several sites in the northeast pacific sampled between 2002 and 2008, tetra- and pentabrominated diphenyl ethers (bdes) (bde 47, 49, 99, and 100) dominated the congener distribution. chinook and sablefish contained the highest concentrations, follow ...201121360729
involvement of serine proteinase in infectious pancreatic necrosis virus capsid protein maturation and ns proteinase cleavage in chse-214 cells.an investigation of virus-specific protein maturation in infectious pancreatic necrosis virus (ipnv) infected chinook salmon embryo cells (chse-214) was undertaken. the precursor protein (pvp2-1) of the major mature capsid protein (vp2) was processed sequentially from pvp2-1 to pvp2-2 and vp2. experiments using serine proteinase inhibitors showed that the maturation of the vp2 was blocked in the pvp2-1 post-translational cleavage steps. a protinin, a potent proteinase inhibitor, at 800 μg ml(-1) ...199821361976
comparison and evaluation of renibacterium salmoninarum quantitative pcr diagnostic assays using field samples of chinook and coho salmon.renibacterium salmoninarum is a gram-positive bacterium causing bacterial kidney disease (bkd) in susceptible salmonid fishes. several quantitative pcr (qpcr) assays to measure r. salmoninarum infection intensity have been reported, but comparison and evaluation of these assays has been limited. here, we compared 3 qpcr primer/probe sets for detection of r. salmoninarum in field samples of naturally exposed chinook and coho salmon first identified as positive by nested pcr (npcr). additional sam ...201121381519
interpreting dual elisa and qpcr data for bacterial kidney disease of salmonids.although there are a variety of methods available for the detection of renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmon and trout, the enzyme-linked immunosorbent assay (elisa) is probably the most widely used method. however, elisa measures bacterial antigen, which does not necessarily reflect the number of cells present. we hypothesized that dual analysis of kidney tissue by elisa and a quantitative real-time polymerase chain reaction assay (qpcr) would pro ...201021387990
distance-based population classification software using mean-field annealing.we describe a distance-based clustering method using a proximity matrix of genetic distances to partition populations into genetically similar groupings. the optimization heuristic mean-field annealing (mfa) was used to find locally optimal solutions where exhaustive search was not possible. to illustrate this method, we analysed both simulated and real data sets. simulated data indicated that mfa successfully differentiated population groups, even with small f(st) values, as long as there was s ...201121429108
development of 54 novel single-nucleotide polymorphism (snp) assays for sockeye and coho salmon and assessment of available snps to differentiate stocks within the columbia river.single-nucleotide polymorphisms (snps) have potential for broad application in population and conservation genetics, but availability of these markers is limited in many nonmodel species. in this study, genomic and expressed sequence tagged (est) sequences from closely related salmonids (chinook salmon and rainbow trout) were used to design primers for amplification and sequencing of sockeye (oncorhynchus nerka) and coho (oncorhynchus kisutch) salmon dna for snp discovery. one hundred and six pr ...201121429160
purification and characterization of a rhamnose-binding chinook salmon roe lectin with antiproliferative activity toward tumor cells and nitric oxide-inducing activity toward murine macrophages.in this study, a rhamnose-binding lectin from the roe of chinook salmon (oncorhynchus tshawytscha) was purified and characterized, and its biological activities were examined in several model systems. chinook salmon roe lectin had a molecular mass of 30 kda and agglutinated rabbit and bovine erythrocytes. the hemagglutination activity of the lectin was not affected by metal ions. the lectin was stable up to 70 °c and between ph 4 and ph 11. chinook salmon roe lectin did not exert antifungal acti ...201121456624
a novel member of the family hepeviridae from cutthroat trout (oncorhynchus clarkii).beginning in 1988, the chinook salmon embryo (chse-214) cell line was used to isolate a novel virus from spawning adult trout in the state of california, usa. termed the cutthroat trout (oncorhynchus clarkii) virus (ctv), the small, round virus was not associated with disease, but was subsequently found to be present in an increasing number of trout populations in the western usa, likely by a combination of improved surveillance activities and the shipment of infected eggs to new locations. here ...201121458509
permanent genetic resources added to molecular ecology resources database 1 may 2009-31 july 2009.this article documents the addition of 512 microsatellite marker loci and nine pairs of single nucleotide polymorphism (snp) sequencing primers to the molecular ecology resources database. loci were developed for the following species: alcippe morrisonia morrisonia, bashania fangiana, bashania fargesii, chaetodon vagabundus, colletes floralis, coluber constrictor flaviventris, coptotermes gestroi, crotophaga major, cyprinella lutrensis, danaus plexippus, fagus grandifolia, falco tinnunculus, fle ...200921564933
the strength and timing of the mitochondrial bottleneck in salmon suggests a conserved mechanism in vertebrates.in most species mitochondrial dna (mtdna) is inherited maternally in an apparently clonal fashion, although how this is achieved remains uncertain. population genetic studies show not only that individuals can harbor more than one type of mtdna (heteroplasmy) but that heteroplasmy is common and widespread across a diversity of taxa. females harboring a mixture of mtdnas may transmit varying proportions of each mtdna type (haplotype) to their offspring. however, mtdna variants are also observed t ...201121655224
human influence on the spatial structure of threatened pacific salmon metapopulations.to remain viable, populations must be resilient to both natural and human-caused environmental changes. we evaluated anthropogenic effects on spatial connections among populations of chinook salmon (oncorhynchus tshawytscha) and steelhead (o. mykiss) (designated as threatened under the u.s. endangered species act) in the lower columbia and willamette rivers. for several anthropogenic-effects scenarios, we used graph theory to characterize the spatial relation among populations. we plotted varian ...201121797926
an evaluation of the influence of stock origin and out-migration history on the disease susceptibility and survival of juvenile chinook salmon.various methods have been developed to mitigate the adverse effects of the federal columbia river power system on juvenile pacific salmon out-migrating through the columbia river basin. in this study, we found that hatchery-reared spring chinook salmon oncorhynchus tshawytscha in the river are in varying degrees of health, which may affect delayed mortality and the assessment of the effectiveness of management actions to recover listed stocks (e.g., barging fish downstream versus leaving fish in ...201121699135
survey of pathogens in hatchery chinook salmon with different out-migration histories through the snake and columbia rivers.the operation of the federal columbia river power system (fcrps) has negatively affected threatened and endangered salmonid populations in the pacific northwest. barging snake river spring chinook salmon oncorhynchus tshawytscha through the fcrps is one effort to mitigate the effect of the hydrosystem on juvenile salmon out-migration. however, little is known about the occurrence and transmission of infectious agents in barged juvenile salmon relative to juvenile salmon that remain in-river to n ...201121834329
self-sustaining populations, population sinks or aggregates of strays: chum (oncorhynchus keta) and chinook salmon (oncorhynchus tshawytscha) in the wood river system, alaska.small populations can provide insights into ecological and evolutionary aspects of species distributions over space and time. in the wood river system in alaska, usa, small aggregates of chinook (oncorhynchus tshawytscha) and chum salmon (o. keta) spawn in an area dominated by sockeye salmon (o. nerka). our objective was to determine whether these chinook and chum salmon are reproductively isolated, self-sustaining populations, population sinks that produce returning adults but receive immigrati ...201122026559
Bacterial infections of Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to gamete collecting weirs in Michigan.Herein, we describe the prevalence of bacterial infections in Chinook salmon, Oncorhynchus tshawytscha (Walbaum), returning to spawn in two tributaries within the Lake Michigan watershed. Ten bacterial genera, including Renibacterium, Aeromonas, Carnobacterium, Serratia, Proteus, Pseudomonas, Hafnia, Salmonella, Shewanella and Morganella, were detected in the kidneys of Chinook salmon (n = 480) using culture, serological and molecular analyses. Among these, Aeromonas salmonicida was detected at ...201222168454
circulating salmon 28- and 22-kda insulin-like growth factor binding proteins (igfbps) are co-orthologs of igfbp-1.circulating insulin-like growth factor binding proteins (igfbps) play pivotal roles in stabilizing igfs and regulating their availability to target tissues. in the teleost circulation, three major igfbps are typically detected by ligand blotting with molecular masses around 20-25, 28-32 and 40-45kda. however, their identity is poorly established and often confused. we previously identified salmon 22- and 41-kda forms as igfbp-1 and -2b, respectively. in the present study, we cloned the cdna of 2 ...201121888908
The use of a real-time PCR primer/probe set to observe infectivity of Yersinia ruckeri in Chinook salmon, Oncorhynchus tshawytscha (Walbaum), and steelhead trout, Oncorhynchus mykiss (Walbaum).Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM), a common pathogen affecting aquaculture facilities and implicated in large losses of cultured fish. Fisheries scientists continue to gain a greater understanding of the disease and the pathogen by investigating methods of identification and pre- and post-infection treatment. In this study, a real-time PCR probe set for Y. ruckeri was developed to detect daily changes in the bacterial load during pathogen challenges. Two s ...201121916903
in situ biomonitoring of caged, juvenile chinook salmon (oncorhynchus tshawytscha) in the lower duwamish waterway.contaminated sediments may have wide-ranging impacts on human and ecological health. a series of in situ caged exposure studies using juvenile chinook salmon was conducted in the lower duwamish waterway (ldw). chemical analysis of sediment, water, and fish tissue were completed. additionally, in 2004, dna adducts in hepatic and gill tissues were measured. gills contained significantly higher dna adducts at stations b2 and b4, prompting further analysis of gills in 2006 and 2007. fluorescent arom ...201121906759
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