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Wayne L. Gray - One of the best experts on this subject based on the ideXlab platform.
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Catfish
2013Co-Authors: Wayne L. Gray, Rhonda J. Williams, Robin L. Jordan, Billy R GriffinAbstract:Detection of Channel Catfish Virus DNA in latently infecte
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Effect of dietary cortisol on resistance of Channel Catfish to infection by Ichthyopthirius multifiliis and Channel Catfish Virus disease
Aquaculture, 2003Co-Authors: Kenneth B Davis, Billy R Griffin, Wayne L. GrayAbstract:Many diseases of fish are more likely to occur after a period of stress. A number of physiological changes occur in fish during stress including the secretion of cortisol. Cortisol has several effects including the induction of gluconeogenesis and immunosuppression. The latter activity of cortisol is thought to be the reason stress is often followed by a disease outbreak. These experiments were done to determine the role of cortisol, in the absence of stress, in affecting the susceptibility of Channel Catfish to Ichthyopthirius multifiliis (ich) and Channel Catfish Virus (CCV). Cortisol mixed in the food resulted in reduced liver size and abolished the increase of plasma cortisol usually induced by confinement stress. Dietary cortisol provided at 200-mg/kg feed increased the susceptibility of Channel Catfish to infection in an immersion challenge with ich theronts. The severity of infection in fish provided cortisol at 100-mg/kg feed was not different than controls. Dietary cortisol at either 100 or 200 mg/kg did not affect mortality due to CCV exposure. These data suggest that increased cortisol suppressed the protective mechanism against ich but not against CCV.
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Channel Catfish Virus gene expression in experimentally infected Channel Catfish, Ictalurus punctatus (Rafinesque)
Journal of Fish Diseases, 2003Co-Authors: Robin L. Stingley, B R Griffin, Wayne L. GrayAbstract:Channel Catfish Virus (CCV) produces an acute haemorrhagic disease in fingerling Channel Catfish and establishes latent infection in fish that survive the primary infection. This study investigated CCV gene expression in tissues of experimentally infected fish. Reverse transcriptase polymerase chain reaction assays were developed for detection of transcripts expressed by each of the CCV direct repeat region genes in CCV-infected Channel Catfish ovary cells and in tissues of infected fish. Immediate-early, early and late gene transcripts were detected in the blood, brain, kidney and liver tissues of acutely infected Catfish demonstrating active viral replication in multiple tissues during the early stages of CCV infection. However, there was no evidence for viral replication by 24 days post-infection in tissues of fish that survived the acute disease. Viral latency-associated transcripts encoded by CCV direct repeat genes were not detected in latently infected Catfish. The results of this study provide a foundation for further studies to investigate the molecular basis of CCV pathogenesis and latency.
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Experimental Channel Catfish Virus Infection Mimics Natural Infection of Channel Catfish
Journal of the Arkansas Academy of Science, 2003Co-Authors: Robin L. Stingley, Wayne L. Gray, Billy R Griffin, Reid LandesAbstract:(Channel Catfish Virus (CCV) causes a severe hemorrhagicdisease in Channel Catfish fry and fingerlings. CCV epizootics j associated withelevated water temperatures and high mortality rates. Survivorsof acute disease are latently infected with i Virus. In this study, we investigated conditions effecting CCV pathogenesis and latency utilizing an experimental mersion model to simulate natural infection and a population of ArkansasCatfish verified to have no prior CCV exposure, e resultsindicate that the Auburn-1 laboratorystrain is comparable to CCV field isolatesin virulenceand abilityto establish ent infection. The studyconfirms that water temperature and fish age effect susceptibility to acute infection. Twenty-four ek old fish were more susceptible to acute CCV infection at 28° C than at 24° C. Eight week old fish were susceptible to ease at 24° C and 28° C. YearlingCatfish,although more resistant to acute disease,were susceptible to latent CCV infection. 2Vlatency was established as early as 27 days followingexperimental infection and maintained for at least one year post ection. The CCV infectionmodel describedin this report is usefulfor furtherinvestigation of CCV pathogenesis and latency and for evaluation of potential antiviral therapies.
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effect of handling stress on susceptibility of Channel Catfish ictalurus punctatus to ichthyophthirius multifiliis and Channel Catfish Virus infection
Aquaculture, 2002Co-Authors: Kenneth B Davis, Billy R Griffin, Wayne L. GrayAbstract:A quantitative bioassay employing immersion exposure was developed for the infection of Channel Catfish Ictalurus punctatus with the protozoan parasite Ichthyophthirius multifiliis, commonly referred to as ich. This bioassay as well as waterborne challenge of Channel Catfish with Channel Catfish Virus (CCV) was used to investigate the effect of confinement stress on the sensitivity of the fish to exposure of these pathogens. Infestation by ich was shown to be proportional to the density of infective theronts in the exposure tank and low-water crowding stress was shown to increase susceptibility of Catfish to infection. Mortality from CCV was related to the Virus exposure dose; however, low-water crowding stress did not affect mortality. Increased susceptibility, due to crowding stress of naive Channel Catfish to I. multifiliis but not to CCV, suggests a difference in the defence mechanisms. Stress-induced increased susceptibility to I. multifiliis may be due to a suppression of an innate protection mechanism. The lack of effect of stress on CCV mortality may be due to protection afforded by an inducible system which was not affected by the stressor, or the lethal effects of the Virus were too fast for the stress to change susceptibility in fish exposed to CCV for the first time.
L A Hanson - One of the best experts on this subject based on the ideXlab platform.
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Antibody response of Channel Catfish after Channel Catfish Virus infection and following dexamethasone treatment
Diseases of Aquatic Organisms, 2011Co-Authors: Ana B. Arnizaut, L A HansonAbstract:Channel Catfish Virus (CCV, Ictalurid herpesVirus 1) and CCV disease have been extensively studied. Yet, little is known about CCV-host interaction after resolution of the primary infection. In order to determine potential recrudescence of CCV from latency, we established latency by exposing Channel Catfish juveniles with CCV or a thymidine kinase-negative recombinant (CCVlacZ) at a dose that caused less than 20% mortality. Then, we evaluated antibody response by serially sampling the same fish at 0 (pre-infection), 30, 60 and 90 d post challenge (DPC). We then attempted to induce viral recrudescence by intramuscular administration of dexamethasone and sampled the fish at 2, 4, 7, or 10 d post treatment. Recrudescence was evaluated by leukocyte co-cultivation and cell culture of tissue homogenates but no Virus was detected. Western blot data demonstrated the highest number of seropositive fish by 30 DPC and a secondary antibody induction after dexamethasone treatment. The antigen specificity of the secondary response corresponded to viral proteins with molecular masses similar to those recognized by the same fish by 30 DPC. The recognized proteins were predominantly large, ranging from approximately 90 to >200 kDa. Expression analysis of selected Virus genes at 90 DPC and following dexamethasone treatment demonstrated occasional immediate-early Virus gene expression in peripheral blood leukocytes. Early and late gene expression was rarely detected. The combined data suggest restricted re-activation of CCV in our experimental system. Primary and secondary responses and Virus gene expression were demonstrated in CCVlacZ-exposed fish but were less frequent than in CCV-exposed fish.
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Evaluation of Channel Catfish Virus Latency on Fingerling Production Farms in Mississippi
Journal of Aquatic Animal Health, 2005Co-Authors: David J. Thompson, David J. Wise, Lester H. Khoo, L A HansonAbstract:Abstract Channel Catfish Virus disease (CCVD) is an economically important disease to the Channel Catfish Ictalurus punctatus industry. Channel Catfish Virus develops a latent infection and is vertically transmitted from broodstock to offspring. In this study, the presence of latent Channel Catfish Virus (CCV) in fry at 3–5 d of age was evaluated, via polymerase chain reaction, on five farms in the Delta region of Mississippi. We found over 10% of the fry sampled were positive for latent CCV on all five farms. Additionally, on one of those farms the presence of latent CCV was evaluated in three ponds through a typical CCVD season. Regression analysis of the CCV carrier level demonstrated an increase, but no overt CCVD outbreaks occurred and no CCV was cultured from the fish tissues in cell culture. Our results indicate that CCV is endemic in most Channel Catfish populations under commercial production in Mississippi and suggests that subclinical transmission of CCV does occur.
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Susceptibility of Channel Catfish fry to Channel Catfish Virus (CCV) challenge increases with age
Diseases of Aquatic Organisms, 2004Co-Authors: L A Hanson, Mary R. Rudis, Lora Petrie-hansonAbstract:Susceptibility of Channel Catfish to Channel Catfish Virus Disease (CCVD) has been generally considered to be inversely related to age. However, in experimental immersion challenges, we found that Channel Catfish fry, 3 to 8 d post hatch (dph), are most resistant to CCV and suscepti- bility increases with age. Initial studies involved 2 spawns that had high CCV carrier percentage. To determine if the resistance seen in the fry was related to the CCV carrier status of the parents, we selected 4 spawns from CCV negative parents and 2 spawns from CCV positive parents and immer- sion challenged them at 8, 23, 36 and 60 dph with 0, 2.5 × 10 4 or 2.5 × 10 6 plaque forming units (PFU) of CCV l -1 . Survivors of the low-dose exposed groups were rechallenged at 120 dph with 2.5 × 10 6 PFU CCV l -1 . Each brood demonstrated increasing susceptibility to CCVD with age and only the fish that were initially exposed at 60 dph developed protective immunity. Time course assays evaluating tissue levels of Virus in Channel Catfish exposed to CCV at 7, 21 and 42 dph suggested that the resis- tance was an early event in the infection process. The resistance in fry was most pronounced in fish from CCV positive spawns and was correlated to neutralizing antibody titers in the maternal parent in the 8 dph challenge. However, other factors may be involved because all groups displayed the ini- tial resistance and subsequent susceptibility to CCVD. The age effect may be an important influence on the progression of CCVD outbreaks and indicates the need to consider age for experimental chal- lenges. Additionally, we documented the level of vertical transmission of CCV. Fry from the 4 positive spawns had a CCV prevalence of 40 to 75%.
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Channel Catfish Virus gene 50 encodes a secreted, mucin-like glycoprotein.
Virology, 1999Co-Authors: Nathalie Vanderheijden, L A Hanson, Etienne Thiry, Joseph MartialAbstract:Cells infected with the wild-type (WT) strain of Channel Catfish Virus (CCV) secreted a glycoprotein with an apparent molecular mass (MM) superior to 200 kDa into the culture medium. This protein, designated gp250, was the sole viral glycoprotein detected in the culture medium after [3H]mannose labeling of the infected cells. When cells were infected with the attenuated V60 strain, a glycoprotein of 135 kDa (designated gp135) was detected instead of gp250. Because WT gene 50 is predicted to encode a secreted, mucin-type glycoprotein, we expressed this gene transiently and detected a glycoprotein of the same apparent MM as gp250 in the culture medium of transfected Catfish cells. The increased mobility in SDS-PAGE of the secreted V60 glycoprotein correlated with the presence of a major deletion in V60 gene 50. Therefore, we concluded that gp250 in the WT and gp135 in the V60 strains are both likely encoded by gene 50. An important shift in the relative mobility of gp250 in SDS-PAGE was observed after tunicamycin treatment of infected cells labeled with [3H]glucosamine, confirming the presence of N-linked sugars on gp250. We observed variations in the size of PCR products derived from gene 50 amplification in three different field isolates. Such genetic variations are a characteristic feature of mucin genes and are linked to crossing-over events between internal repeated sequences, such as those present in gene 50.
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Temporal Gene Regulation of the Channel Catfish Virus (Ictalurid HerpesVirus 1)
Journal of Virology, 1998Co-Authors: Suming Huang, L A HansonAbstract:To identify promoter regions that impart differential temporal regulation of Channel Catfish Virus (CCV) genes, the transcriptional kinetics of an immediate-early gene and prospective early and late genes were characterized. A cDNA clone, designated IE3C, representing a third immediate-early transcript was identified. The 5′ end of the IE3C transcript was mapped to nucleotides 15,368 and 131,043 in the terminal repeat regions of the CCV genome. The full length of the transcript represented by the IE3C clone is 1,412 bp, and it most likely codes for the protein specified by open reading frame (ORF) 12. The putative product of ORF12 contains a consensus RING finger metal binding motif (C3HC4 structure). Temporal expression studies, in conjunction with protein synthesis and DNA replication inhibition, demonstrated that the IE3C transcript belongs to an immediate-early kinetic class, the ORF5 transcript is a member of the early kinetic class, and ORF39 and ORF46 are true late-kinetic-class genes. Additionally, we demonstrated that ORF38 transcription overlaps ORF39 and the products presumably share the same poly(A) signal. The 5′ ends of the transcripts encoding ORF38, ORF39, and ORF46 were mapped to nucleotides 44,862, 45,254, and 59,644, respectively, and potential transcriptional control elements were located.
Andrew J. Davison - One of the best experts on this subject based on the ideXlab platform.
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Fish and Amphibian HerpesViruses
Encyclopedia of Virology, 2008Co-Authors: Andrew J. DavisonAbstract:Viruses that infect mammals (particularly humans) and birds dominate studies of the family Herpesviridae. However, several herpesViruses exist that infect fish, and some of these cause devastating losses in economically important species. This article describes the virology of fish herpesViruses and their relatives in amphibians, focusing on three of the most extensively characterized representatives: Channel Catfish Virus, koi herpesVirus, and Lucke tumor herpesVirus of frogs.
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The Capsid Architecture of Channel Catfish Virus, an Evolutionarily Distant HerpesVirus, Is Largely Conserved in the Absence of Discernible Sequence Homology with Herpes Simplex Virus
Virology, 1996Co-Authors: Frank P. Booy, Andrew J. Davison, Benes L. Trus, Alasdair C. StevenAbstract:Although herpesViruses have a wide host range and their genomes vary substantially in size, the nucleocapsid appears to be a conservative element of viral design. The capsid shell is icosahedrally symmetric (T = 16), and 125 nm in diameter and 15nm thick in the case of herpes simplex Virus 1 (HSV-1). Channel Catfish Virus (CCV) has the gross morphology of a herpesVirus, although no relationship to other herpesViruses is evident from the sequences of its proteins. To examine CCV capsid architecture more closely, we have determined its structure by cryoelectron microscopy and three-dimensional image reconstruction. The CCV capsid is smaller than that of HSV-1, but its 12% smaller genome is packed to essentially the same average density; its icosahedral facets are flatter, and its shell is about 20% thinner, consistent with the smaller size of its major capsid protein. Otherwise, their major features are remarkably similar: CCV has the same triangulation number; its hexons and pentons also have chimney-like protrusions with an axial Channel through each capsomer; and there are "triplexes" on the outer surface at the sites of local threefold symmetry. The basic herpesVirus capsid architecture is, therefore, remarkably well conserved in CCV and implies a utilitarian basis to this design. The protein composition of CCV mirrors that of HSV-1, except for the absence of the 12-kDa protein, VP26, which is dispensable for assembly in the HSV-1 system and, apparently, wholly dispensable for CCV.
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Identification of structural proteins of Channel Catfish Virus by mass spectrometry.
Virology, 1995Co-Authors: Andrew J. Davison, Matthew D. DavisonAbstract:Emerging methods that couple mass spectrometry of fragments generated from isolated proteins with database searching offer a powerful means of identifying proteins and the genes that encode them. We have applied this technology to a herpesVirus, Channel Catfish Virus, and have identified 12 genes, 11 viral and 1 cellular, that encode 16 principal structural proteins. These proteins include three components of the mature capsid and a potential scaffolding protein present in immature capsids, three protein kinases, a C3HC4 zinc-binding protein and cellular actin located in the tegument, and a multiply hydrophobic protein associated with the envelope.
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Capsid structure of Channel Catfish Virus, an evolutionarily distant herpesVirus, by cryo-Electron Microscopy
Proceedings annual meeting Electron Microscopy Society of America, 1994Co-Authors: Benes L. Trus, Andrew J. Davison, Frank P. Booy, Alasdair C. StevenAbstract:HerpesViruses comprise an extensive family of enveloped DNA-containing animal Viruses. Although they infect a wide range of vertebrate hosts and their linear double-stranded genomes vary substantially in size and other properties, the nucleocapsid appears to be a conservative element of viral design. The capsid shell is icosahedrally symmetric (T=16), and in the case of alphaherpesViruses is 125 nm in diameter and 15nm thick. Recently, we have studied the molecular anatomy of herpes simplex Virus1 (HSV-1), whose capsid contains four major proteins, by combining cryo-electron microscopy and 3-dimensional reconstruction with biochemical depletion experiments and antibody-labelling. In order to probe structural perturbations attributable to evolutionary differences, we have extended these studies to Channel Catfish Virus. CCV exhibits the gross morphology of a herpesVirus, although no evident relationship to other herpesViruses was found in an analysis of proteins predicted from its complete DNA sequence.
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Channel Catfish Virus : a new type of herpesVirus
Virology, 1992Co-Authors: Andrew J. DavisonAbstract:HerpesViruses are large double-stranded DNA Viruses which infect vertebrates from fish to man. Convincing genetic relationships between herpesViruses that infect higher vertebrates (birds and mammals) have been demonstrated previously by comparing proteins predicted from DNA sequences and have been interpreted as a result of evolution from a common ancestor. In order to evaluate how herpesViruses of lower vertebrates fit into this scheme, the 134,226-bp genome of Channel Catfish Virus was sequenced. Genetic comparisons indicate that a separate evolutionary origin for this Virus must be considered. The findings impact upon current perceptions of herpesVirus evolution and gene function.
Joseph Martial - One of the best experts on this subject based on the ideXlab platform.
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Channel Catfish Virus gene 50 encodes a secreted, mucin-like glycoprotein.
Virology, 1999Co-Authors: Nathalie Vanderheijden, L A Hanson, Etienne Thiry, Joseph MartialAbstract:Cells infected with the wild-type (WT) strain of Channel Catfish Virus (CCV) secreted a glycoprotein with an apparent molecular mass (MM) superior to 200 kDa into the culture medium. This protein, designated gp250, was the sole viral glycoprotein detected in the culture medium after [3H]mannose labeling of the infected cells. When cells were infected with the attenuated V60 strain, a glycoprotein of 135 kDa (designated gp135) was detected instead of gp250. Because WT gene 50 is predicted to encode a secreted, mucin-type glycoprotein, we expressed this gene transiently and detected a glycoprotein of the same apparent MM as gp250 in the culture medium of transfected Catfish cells. The increased mobility in SDS-PAGE of the secreted V60 glycoprotein correlated with the presence of a major deletion in V60 gene 50. Therefore, we concluded that gp250 in the WT and gp135 in the V60 strains are both likely encoded by gene 50. An important shift in the relative mobility of gp250 in SDS-PAGE was observed after tunicamycin treatment of infected cells labeled with [3H]glucosamine, confirming the presence of N-linked sugars on gp250. We observed variations in the size of PCR products derived from gene 50 amplification in three different field isolates. Such genetic variations are a characteristic feature of mucin genes and are linked to crossing-over events between internal repeated sequences, such as those present in gene 50.
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The attenuated V60 strain of Channel Catfish Virus possesses a deletion in ORF50 coding for a potentially secreted glycoprotein.
Virology, 1996Co-Authors: Nathalie Vanderheijden, Philippe Alard, C. Lecomte, Joseph MartialAbstract:Abstract A wild-type strain of Channel Catfish Virus was compared at the genomic level with the attenuated strain V60. In addition to several minor differences, restriction mapping revealed one major deletion (approximately 1200 bp) in ORF50 of the V60 strain. Cloning and sequencing of part of this ORF confirmed the presence of a 1164-bp deletion. It should result in a protein of 282 amino acids instead of 670. The predicted truncated protein lacks most of a threonine-rich, highly repetitive region in its central part. Since the protein encoded by ORF50 possesses a hydrophobic N-terminal leader sequence and no membrane anchor sequence, we suggest that it could be a secreted glycoprotein. This protein might be N -glycosylated (35 potential sites) and, given the repetitive arrangement of its residues (mainly threonines), also heavily O -glycosylated like the mucin-type glycoproteins. The deletion observed in ORF50 of the V60 strain implies the loss of 24 potential N -glycosylation sites and should considerably reduce the extent of O -glycosylation.
P S Silverstein - One of the best experts on this subject based on the ideXlab platform.
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Differential susceptibility of blue Catfish, Ictalurus furcatus (Valenciennes), Channel Catfish, I. punctatus (Rafinesque), and blue · Channel Catfish hybrids to Channel Catfish Virus
Journal of Fish Diseases, 2007Co-Authors: P S Silverstein, Brian G Bosworth, Patricia S. GauntAbstract:Channel Catfish Virus (CCV), also known as ictalurid herpesVirus-1 (IHV-1), primarily affects juvenile Channel Catfish, Ictalurus punctatus (Rafinesque), that are less than 6 months old and was first reported by Fijan (1968). CCV outbreaks can be sporadic, and are usually associated with fry and fingerlings when the water temperature is above 25 C (Plumb 1978). The Virus has been reported to be transmitted vertically (Wise, Harrell, Busch & Boyle 1988) and horizontally (reviewed in Plumb 1978). The external signs of CCV disease (CCVD) include exophthalmia, distended abdomen and haemorrhages at the bases of fins. The trunk kidney may exhibit oedema and necrosis, and this tissue is commonly used to confirm the presence of the Virus using a tissue culture assay (reviewed in Wolf 1988). In addition, the Virus appears to maintain a latent state in leucocytes (Bowser, Munson, Jarboe, Francis-Floyd & Waterstrat 1985), which raises the possibility that latent CCV infection may alter the immune response to other pathogens. It has been over 30 years since it was determined that different strains of Catfish exhibited differential resistance to CCV when the Virus was mixed with their feed (Plumb, Green, Smitherman & Pardue 1975). A subsequent study by Plumb & Chappell (1978) examined the relative susceptibility of blue Catfish, I. furcatus (Valenciennes), and reciprocal blue · Channel hybrids to CCV. Since Plumb s (1978) study, there have been no reports on the relative susceptibility of blue Catfish or hybrids to CCV. The present study was conducted to determine the relative susceptibility of four different groups of fish: blue Catfish, a blue · Channel hybrid, a group of Channel Catfish obtained from 10 farms in the Mississippi Delta, hereafter referred to as the industry pool (IP), and a new strain of Catfish produced by the Catfish Genetics Research Unit of USDA at Stoneville, MS (USDA 102 · 103). For each strain of fish, nine replicate tanks were stocked with 40 fish per tank; eight tanks were used for Virus challenge while the remaining tank was used as an uninfected control. Fish were placed in 38 L tanks that were filled to 11 L and had a flowthrough rate of 1.8 L min and allowed to acclimatize for 8 days. Fish were fed to satiation twice per day beginning the day after stocking and feeding continued throughout the course of the study. The blue Catfish (avg. wt. 3.45 0.18 g) used in this study were of the D and B strain. Fry from seven different spawns were pooled and raised communally in tanks until used in the challenge. The hybrid Catfish (avg. wt. 4.10 0.21 g) were produced by crossing female USDA 103 strain Channel Catfish and D and B strain blue Catfish. Twelve hybrid spawns were pooled and used in this Journal of Fish Diseases 2008, 31, 77–79
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differential susceptibility of blue Catfish ictalurus furcatus valenciennes Channel Catfish i punctatus rafinesque and blue x Channel Catfish hybrids to Channel Catfish Virus
Journal of Fish Diseases, 2007Co-Authors: P S Silverstein, Brian G Bosworth, Patricia S. GauntAbstract:Channel Catfish Virus (CCV), also known as ictalurid herpesVirus-1 (IHV-1), primarily affects juvenile Channel Catfish, Ictalurus punctatus (Rafinesque), that are less than 6 months old and was first reported by Fijan (1968). CCV outbreaks can be sporadic, and are usually associated with fry and fingerlings when the water temperature is above 25 C (Plumb 1978). The Virus has been reported to be transmitted vertically (Wise, Harrell, Busch & Boyle 1988) and horizontally (reviewed in Plumb 1978). The external signs of CCV disease (CCVD) include exophthalmia, distended abdomen and haemorrhages at the bases of fins. The trunk kidney may exhibit oedema and necrosis, and this tissue is commonly used to confirm the presence of the Virus using a tissue culture assay (reviewed in Wolf 1988). In addition, the Virus appears to maintain a latent state in leucocytes (Bowser, Munson, Jarboe, Francis-Floyd & Waterstrat 1985), which raises the possibility that latent CCV infection may alter the immune response to other pathogens. It has been over 30 years since it was determined that different strains of Catfish exhibited differential resistance to CCV when the Virus was mixed with their feed (Plumb, Green, Smitherman & Pardue 1975). A subsequent study by Plumb & Chappell (1978) examined the relative susceptibility of blue Catfish, I. furcatus (Valenciennes), and reciprocal blue · Channel hybrids to CCV. Since Plumb s (1978) study, there have been no reports on the relative susceptibility of blue Catfish or hybrids to CCV. The present study was conducted to determine the relative susceptibility of four different groups of fish: blue Catfish, a blue · Channel hybrid, a group of Channel Catfish obtained from 10 farms in the Mississippi Delta, hereafter referred to as the industry pool (IP), and a new strain of Catfish produced by the Catfish Genetics Research Unit of USDA at Stoneville, MS (USDA 102 · 103). For each strain of fish, nine replicate tanks were stocked with 40 fish per tank; eight tanks were used for Virus challenge while the remaining tank was used as an uninfected control. Fish were placed in 38 L tanks that were filled to 11 L and had a flowthrough rate of 1.8 L min and allowed to acclimatize for 8 days. Fish were fed to satiation twice per day beginning the day after stocking and feeding continued throughout the course of the study. The blue Catfish (avg. wt. 3.45 0.18 g) used in this study were of the D and B strain. Fry from seven different spawns were pooled and raised communally in tanks until used in the challenge. The hybrid Catfish (avg. wt. 4.10 0.21 g) were produced by crossing female USDA 103 strain Channel Catfish and D and B strain blue Catfish. Twelve hybrid spawns were pooled and used in this Journal of Fish Diseases 2008, 31, 77–79
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Immediate-early transcription from the Channel Catfish Virus genome: characterization of two immediate-early transcripts.
Journal of virology, 1995Co-Authors: P S Silverstein, Vicky L. Van Santen, R. C. Bird, Kenneth E. NusbaumAbstract:With cDNA probes and by Northern (RNA) blot analysis, a region containing immediate-early (IE) genes in the Channel Catfish Virus (CCV) genome was identified. IE transcription in CCV-infected cells appears to be restricted to the terminal repeat region, suggesting that CCV is most closely related to the alpha subfamily of herpesViruses. CCV DNA fragments from this region encoding IE transcripts were cloned. Northern analysis with one of these cloned fragments, a 3,927-bp EcoRI-XbaI fragment, indicates that it encodes two IE transcripts. Both transcripts (ie1 and ie2) were characterized by S1 nuclease analysis, primer extension analysis, and analysis of cDNAs. The ie2 transcript is a 1.3-kb bicistronic mRNA containing open reading frame (ORF) 8a and ORF 9. ORF 8a is a 5'-truncated version of ORF 8 which, along with ORF 9, was previously identified (A. J. Davison, Virology 186:9-14, 1992). The ie1 transcript is 0.6 kb in size, contains only ORF 9, and is expressed at a level approximately six times that of ie2 in cycloheximide-treated cells. The putative product of ORF 9 is predicted to have a basic pI and contains a potential zinc-binding domain, making it a probable transcription factor. ORF 8a encodes a putative product which is very hydrophobic, an unusual characteristic for an IE protein.