| [emerging of avian leukosis virus subgroup j in a flock of chinese local breed]. | myeloid leukosis (ml) cases were first diagnosed in a chicken flock of chinese local breed in shan dong province. the main symptom included wasting, weight loss, anemia. it caused about 10% mortality of about 15000 birds at the age of 120-day. in the necropsy, gray-white nodules and protrusions in various sizes were commonly observed on the surface of the sternum, intestine and trachea. almost all viscera tissues showed moderate to severe enlargement with diffuse gray-white nodules. histological ... | 2005 | 16245876 |
| malignant transformation of an epithelial cell by v-src via tv-a-mediated retroviral infection: a new cell model for studying carcinogenesis. | most human cancers are of epithelial origin, but many cell culture models for the study of cancer-causing genes use fibroblasts. in addition, efficient delivery and stable expression of foreign genes into non-transformed cell lines are often difficult. to address both questions, we here established a non-transformed rat kidney epithelial rk3e cell line that constitutively expresses tv-a (receptor for subgroup a avian leukosis virus, alv) for delivery of foreign genes via avian retroviral infecti ... | 2005 | 16256070 |
| development and validation of a pcr-rflp assay to evaluate tvb haplotypes coding receptors for subgroup b and subgroup e avian leukosis viruses in white leghorns. | the cellular receptor of subgroup b avian leukosis virus (alvb) is encoded by a gene at the tumour virus b (tvb) locus. tvb alleles encode specific receptors permitting infection by exogenous alvb or avian leukosis virus subgroup d (alvd) as well as endogenous avian leukosis virus subgroup e (alve), and thus susceptibility is dominant to resistance. two single nucleotide polymorphisms at the tvb locus have been reported distinguishing three tvb alleles (tvb*s1, tvb*s3 and tvb*r). we have develop ... | 2005 | 16147569 |
| novel criteria for the diagnosis of marek's disease virus-induced lymphomas. | several novel criteria have been tested to assist in the differential diagnosis of tumours induced by marek's disease virus (mdv) from those induced by avian leukosis virus (alv) and reticuloendotheliosis virus (rev). a collection of tumours induced by inoculation of specific strains of mdv, alv and rev, alone or in combination, were tested for quantification of mdv dna by real-time polymerase chain reaction, expression of the mdv oncogene meq, expression of several cell markers associated with ... | 2005 | 16147570 |
| replacement of primary chicken embryonic fibroblasts (cef) by the df-1 cell line for detection of avian leucosis viruses. | international regulations prescribe that the absence of avian leucosis viruses (alv) in avian live virus vaccines has to be demonstrated. primary chicken embryo fibroblasts (cef) from special spf chicken lines are normally used for detection of alv. the suitability of the df-1 cell line for alv-detection, as alternative for primary cef, was studied in three types of experiments: (1) in titration experiments without cell passage, (2) in experiments with passages in cell cultures according to euro ... | 2006 | 16257542 |
| complete association between a retroviral insertion in the tyrosinase gene and the recessive white mutation in chickens. | in chickens, three mutant alleles have been reported at the c locus, including the albino mutation, and the recessive white mutation, which is characterized by white plumage and pigmented eyes. the albino mutation was found to be a 6 bp deletion in the tyrosinase (tyr) gene. the present work describes an approach to identify the structural rearrangement in the tyr gene associated with the recessive white mutation. | 2006 | 16457736 |
| replicative fidelity of lentiviral vectors produced by transient transfection. | previous investigations have estimated the human immunodeficiency virus type 1 (hiv) base pair substitution rate to be approximately 10(-4) to 10(-5) per round of viral replication, and hiv has been hypothesized to be more error-prone than other retroviruses. using a single cycle reversion assay, we unexpectedly found that the reversion rates of hiv, avian leukosis virus and moloney murine leukemia virus were the same, within statistical error. because both the viral enzyme reverse transcriptase ... | 2006 | 16469344 |
| nested polymerase chain reaction for detection of the avian leukosis virus causing so-called fowl glioma. | the complete nucleotide sequence of the avian leukosis virus causing so-called fowl glioma has been previously determined. primers were designed for detection of the fowl glioma-causal virus (fgv) based on the 3' untranslated region of the viral genome. the provirus and viral rna of fgv were specifically detected in various organs and tissues, including feather pulp, from experimentally infected birds using nested polymerase chain reaction (pcr) and reverse transcription nested pcr. the prevalen ... | 2005 | 16537161 |
| na+/h+ exchanger type 1 is a receptor for pathogenic subgroup j avian leukosis virus. | subgroup j avian leukosis virus (alv-j) is a recently identified avian oncogenic retrovirus responsible for severe economic losses worldwide. in contrast with the other alv subgroups, alv-j predominantly induces myeloid leukosis in meat-type chickens. despite significant homology with the other alv subgroups across most of the genome, the envelope protein of alv-j (envj) shares low homology with the others. pathogenicity and myeloid leukosis induction map to the env gene of alv-j. a chimeric pro ... | 2006 | 16567631 |
| cerebellar hypoplasia associated with an avian leukosis virus inducing fowl glioma. | fowl glioma-inducing virus (fgv), which belongs to subgroup a of avian leukosis virus (alv), shows tumorigenicity and pathogenicity, mainly in the nervous system, and causes astrocytoma and perineurioma. apart from these neoplasms, cerebellar anomaly was found in chickens infected with fgv in ovo. the study reported here describes the morphologic characteristics of the affected cerebellum. specific-pathogen-free chickens (c/o) were inoculated with fgv through the yolk sac on the 7th day of incub ... | 2006 | 16672576 |
| lymphoid organ size varies among inbred lines 6(3) and 7(2) and their thirteen recombinant congenic strains of chickens with the same major histocompatibility complex. | the objective was to evaluate lymphoid organ size in chickens from a series of 13 recombinant congenic strains (rcs) and their highly inbred parental lines (6(3) and 7(2)). the parental line 6(3) was selected for resistance to tumors induced by marek's disease virus and avian leukosis viruses, whereas line 7(2) was selected for susceptibility to these tumors. each rcs on the average contains a random one-eighth of genome from the donor line 7(2). previous studies have shown that lines 6(3) and 7 ... | 2006 | 16673761 |
| acquisition of new dna sequences after infection of chicken cells with avian myeloblastosis virus. | dna-rna hybridization studies between 70s rna from avian myeloblastosis virus (amv) and an excess of dna from (i) amv-induced leukemic chicken myeloblasts or (ii) a mixture of normal and of congenitally infected k-137 chicken embryos producing avian leukosis viruses revealed the presence of fast- and slow-hybridizing virus-specific dna sequences. however, the leukemic cells contained twice the level of amv-specific dna sequences observed in normal chicken embryonic cells. the fast-reacting seque ... | 1974 | 16789139 |
| evolution of gp85 gene of subgroup j avian leukosis virus under the selective pressure of antibodies. | subgroup j avian leucosis virus (alv-j) strain nx0101 was inoculated into chicken embryo fibroblasts (cef) monolayers in 6-well plates. the six wells of cef inoculated with nx0101 were divided into groups a (without anti-alv-j serum in the medium) and b (with anti-alv-j serum in the medium), then viruses from each well of both groups were separately passed in cef every 6 d and formed their independent passage lineages. for each lineage of both groups, gp85 genes of the viruses in the 10th, 20th ... | 2006 | 16856491 |
| reduced serologic response to newcastle disease virus in broiler chickens exposed to a chinese field strain of subgroup j avian leukosis virus. | in this study, a chinese field strain of subgroup j avian leukosis virus (alv-j), nx0101, was studied for its immunosuppressive effects in both commercial broilers and spf white leghorn chickens infected at 1 day of age. our data demonstrated that nx0101 induced much more significant body and immune organ weight loss in the infected commercial broiler chickens in an earlier age than that in the spf white leghorn chickens. at the same time antibody responses to vaccinations of newcastle disease v ... | 2006 | 16863066 |
| experimental infection with avian leukosis virus isolated from marek's disease vaccines. | recently, avian leukosis virus (alv) was isolated from four lots of marek's disease vaccine produced by two laboratories. the alvs isolated were characterized by examination of their interactions with cells of two phenotypes (c/e and c/a,e), subgroup-specific polymerase chain reaction (pcr), virus neutralization, envelope gene sequencing, and phylogenetic analysis. all four alvs are exogenous, belong to subgroup a, and appear to be virtually identical to each other based on pcr and envelope gene ... | 2006 | 16863073 |
| sarcomas and myelocytomas induced by a retrovirus related to myeloblastosis-associated virus type 1 in white leghorn egg layer chickens. | an outbreak of subcutaneous sarcomas in commercial white leghorn egg layers was observed in the northeastern united states during late 2004. subcutaneous tumors were confined to three flocks distributed in two locations and belonging to the same company. the tumors were first observed grossly by farm personnel at approximately 7 wk of age and persisted throughout the economic life of the flocks. most of the tumors observed during the growing period were present on the facial region or around the ... | 2006 | 16863068 |
| detection and characterization of avian leukosis virus in marek's disease vaccines. | avian leukosis virus (alv) infection in chickens is known to induce increased mortality, tumors, delayed growth, and suboptimal egg production. countries importing specified pathogen-free eggs, vaccines, and poultry breeding stock require freedom of infection or contamination with alv in such products among other avian pathogens. recently, alv was found as a contaminant in a limited number of commercial poultry vaccines, even after routine quality assurance procedures cleared the vaccines for co ... | 2006 | 16863069 |
| seroprevalence of avian influenza virus, infectious bronchitis virus, reovirus, avian pneumovirus, infectious laryngotracheitis virus, and avian leukosis virus in nigerian poultry. | eight poultry farms in nigeria, including chickens from nine breeder, 14 broiler, 28 pullet, 11 layer, and three cockerel flocks, were tested for antibody seroprevalence to the following poultry viruses of potential economic importance: infectious bronchitis virus (ibv), avian reovirus, avian pneumovirus (apv), infectious laryngotracheitis virus (iltv), avian influenza virus (aiv), and avian leukosis virus (alv). serum samples were collected between 1999 and 2004 and were tested for antibodies u ... | 2006 | 16863071 |
| e (xsr) element contributes to the oncogenicity of avian leukosis virus (subgroup j). | among the six subgroups of avian leukosis virus (alv) that infect chickens, subgroup j (alv-j) was isolated from meat-type chickens where it predominantly induces myeloid leukosis (ml) and erythroblastosis (eb). the sequence of hprs-103, the alv-j prototype virus, shows several distinct features, one of which is the presence of a distinct hairpin stem-loop structure called the e (also called xsr) element in the 3' untranslated region. in order to determine the role of the e element in alv-induce ... | 2006 | 16894209 |
| susceptibility of various parental lines of commercial white leghorn layers to infection with a naturally occurring recombinant avian leukosis virus containing subgroup b envelope and subgroup j long terminal repeat. | chickens from seven different parental lines of commercial white leghorn layer flocks from three independent breeders were inoculated with a naturally occurring avian leukosis virus (alv) containing an alv-b envelope and an alv-j long terminal repeat (ltr) termed alv-b/j. additional groups of chickens from the same seven parental lines were inoculated with alv-b. chickens were tested for alv viremia and antibody at 0, 4, 8, 16, and 32 wk postinfection. chickens from all parental lines studied we ... | 2006 | 17039832 |
| isolation and characterization of an adventitious avian leukosis virus isolated from commercial marek's disease vaccines. | commercial marek's disease (md) vaccines produced by two manufacturers were tested for possible contamination with avian leukosis virus (alv). samples of md vaccines manufactured by two companies (a and b) were received from a breeder company; samples were also received directly from vaccine company b. using virus isolation tests, samples initially tested positive for subgroup e (endogenous) alv. however, upon repassage, the vaccines also tested positive for exogenous alv. the isolated exogenous ... | 2006 | 17039837 |
| major rearrangements in the e element and minor variations in the u3 sequences of the avian leukosis subgroup j provirus isolated from field myelocytomatosis. | we collected paraffin-embedded myelocytomatoses induced by subgroup j avian leukosis virus (alv-j) in french poultry from 1992 to 2000. we used nested pcr to obtain the u3 ltr and the e element sequences that encompass putative binding sites for transcription factors. we observed minor mutations in the u3 sequences that rarely affected transcription factor binding sites, thus preserving the transcriptional potential of the u3 ltr. however, we observed a large variability in the e element sequenc ... | 2006 | 16906478 |
| myotropic avian leukosis virus subgroup j infection in a chicken. | the study describes a highly productive myotropic avian leukosis virus infection (alv) in a 3-month-old female chicken. at necropsy, ascites, hepatic fibrosis and cardiomegaly were seen. histologically, the most striking lesion was the presence of cytoplasmic basophilic inclusions in myocardial fibers. immunostaining for alv group specific antigen p27 revealed a diffuse presence of virus antigen in cardiac myofibers, in smooth muscle fibers of most of the organs, and in rare, pancreatic and ovar ... | 2006 | 16930280 |
| a miniaturized germanium-doped silicon dioxide-based surface plasmon resonance waveguide sensor for immunoassay detection. | a surface plasmon resonance (spr) waveguide immunosensor fabricated by germanium-doped silicon dioxide was investigated in this study. the designed waveguide sensor consisted of a 10 microm sio(2) substrate layer (n=1.469), a 10 microm ge-sio(2) channel guide (n=1.492) and a 50 nm gold film layer for immobilization of biomolecules and spr signal detection. the resultant spectral signal was measured by a portable spectrophotometer, where the sensor was aligned by a custom-designed micro-positione ... | 2006 | 16962763 |
| introduction of oncogenes into mammary glands in vivo with an avian retroviral vector initiates and promotes carcinogenesis in mouse models. | we have adapted the avian leukosis virus rcas (replication-competent avian sarcoma-leukosis virus ltr splice acceptor)-mediated somatic gene transfer technique to introduce oncogenes into mammary cells in mice transgenic for the avian subgroup a receptor gene, tva, under control of the mouse mammary tumor virus (mmtv) promoter. intraductal instillation of an rcas vector carrying the polyoma middle t antigen (pymt) gene (rcas-pymt) induced multiple, oligoclonal tumors within 3 weeks in infected m ... | 2006 | 17090666 |
| molecular and biological characterization of a naturally occurring recombinant subgroup b avian leukosis virus with a subgroup j-like long terminal repeat. | infection of broiler chickens with subgroup j avian leukosis virus (alv) results in the induction of myeloid tumors. however, although egg-type chickens are susceptible to infection with alv-j, the tumor incidence is very low, and on rare occasions the tumors observed are of the myeloid lineage. we recently described the isolation of an alv (af115-4) from commercial egg-type chickens suffering from myeloid leukosis. af115-4 was initially identified as an alv-j isolate based on pcr analysis of th ... | 2006 | 17274296 |
| differences in pathogenicity among strains of the same or different avian leukosis virus subgroups. | an efficient induction of wasting disease in chickens by avian leukosis virus (alv), particularly alv subgroup c, requires >102 infectious units virus inoculated in mid embryogenesis. the most conspicuous symptoms of the disease were induced by alv subgroup c; however, significant differences in the occurrence of wasting disease were found among individual members of this subgroup. almost comparable pathogenicity was exhibited by alv subgroup d, whereas viruses of subgroups b and a proved to be ... | 2007 | 17364506 |
| basophilic intracytoplasmic viral matrix inclusions distributed widely in layer hens affected with avian-leukosis-virus-associated tumours. | layer hens (310 days old) affected with subcutaneous tumours were investigated pathologically. basopholic intracytoplasmic viral matrix inclusions (mis) were widely distributed in the chickens affected with subcutaneous myxoma rhabdomyosarcoma, perineuroma, glioma, intra-abdominal adenocarcinoma, and nephroblastoma. mis were observed in the myocardial cells and the impulse-conducting-system cells. they were also present in the smooth muscle cells of the arteries in the spleen and lungs, in the s ... | 2007 | 17364510 |
| retroviral inclusions in the enteric smooth muscle of a tumor-bearing young chicken. | a 15-cm segment of small intestine from a 7-wk-old broiler chicken presented for slaughter was encased by a firm, white mass. other tissues were grossly unremarkable. microscopically, the enteric serosa and peripheral muscularis of this segment of small intestine were replaced by a fibrosarcoma. numerous linear, intracytoplasmic, eosinophilic inclusion bodies were present in smooth muscle cells of the muscularis of the small intestine, and a few similar inclusions were present in the muscularis ... | 2007 | 17461280 |
| inhibition of avian leukosis virus replication by vector-based rna interference. | rna interference (rnai) has recently emerged as a promising antiviral technique in vertebrates. although most studies have used exogenous short interfering rnas (sirnas) to inhibit viral replication, vectors expressing short hairpin rnas (shrna-mirs) in the context of a modified endogenous micro-rna (mirna) are more efficient and are practical for in vivo delivery. in this study, replication competent retroviral vectors were designed to deliver shrna-mirs targeting subgroup b avian leukosis viru ... | 2007 | 17493657 |
| genetic variation at the tumour virus b locus in commercial and laboratory chicken populations assessed by a medium-throughput or a high-throughput assay. | the tumour virus b (tvb) locus encodes cellular receptors mediating infection by three subgroups of avian leukosis virus (b, d, and e). three major alleles, tvb*s1, tvb*s3, and tvb*r, have been described. tvb*s1 encodes a cellular receptor mediating infection of subgroups b, d, and e. tvb*s3 encodes the receptor for two subgroups, b and d, and tvb*r encodes a dysfunctional receptor that does not permit infection by any of the subgroups, b, d, or e. genetic diversity at the tvb locus of chickens ... | 2007 | 17620174 |
| basic cell culture conditions. | the dt40 cell line is derived from alv (avian leukosis virus)-transformed bursal b cell of chicken. this cell line is suspension cell, and can be cultured in cell culture bottles and in culture plates (6-, 24- and 96-well etc.). optimal culture temperature for the dt40 is (39 degrees c-) 41 degrees c, because chicken has higher body temperature than human and mouse. here we summarize protocols for culture medium and condition of the dt40 cell line. | 2006 | 17623916 |
| analysis of gene expression, copy number and palindrome formation with a dt40 enriched cdna microarray. | dt40 presents a unique opportunity to exploit newly available tools for chicken genomic analysis. a 13k chicken cdna microarray representing 11447 non-overlapping ests has been developed. this array detects expression of 7086 dt40 genes of which_644 are over-expressed 3-fold or greater and 1585 are under-expressed 3-fold or greater relative to normal post-hatch bursal cell populations. changes in rna expression due to single gene alterations can be detected by expression profiling. for example, ... | 2006 | 17623909 |
| epidemiological and pathological studies of subgroup j avian leukosis virus infections in chinese local "yellow" chickens. | epidemiological, pathological and molecular studies indicate that subgroup j avian leukosis virus (alv-j) infections are widely spread in "yellow chickens" of local breeds in china. alv-j induced tumour mortality and the serological conversion rates to alv-j were very high in some breeder flocks. typical myelocytomatosis was demonstrated not only in livers, spleens, kidneys, and sternums, as in white meat-type chickens, but also in thymuses and the bursa of fabricius. especially, severe myeloid ... | 2007 | 17497335 |
| evidence for virus closely related to avian myeloblastosis-associated virus type 1 in a commercial stock of chickens. | a two-round nested polymerase chain reaction assay detected rous associated virus-1 (rav-1), a prototype laboratory strain of avian leukosis virus of subgroup a (alv-a). surprisingly, the test failed to detect three field isolates of alv-a but did detect virus in one commercial stock of chickens (stock f). the sequence analysis of a core of 290 nucleotides of the env gene gave evidence that the virus from stock f was closely related to avian myeloblastosis-associated virus type one (mav-1). othe ... | 2003 | 17585462 |
| transduction of rhesus macaque hematopoietic stem and progenitor cells with avian sarcoma and leukosis virus vectors. | genome-wide integration site analyses showed that moloney murine leukemia virus (momlv)- and lentivirus-derived vectors integrate preferentially into the coding regions of genes, posing a risk of insertional mutagenesis. avian sarcoma and leukosis viruses (aslvs) were previously reported to have a weak preference for gene-coding regions in a cell line study as compared with human immunodeficiency virus and momlv; however, thus far these vectors have not been studied for their potential efficacy ... | 2007 | 17655493 |
| structural requirements for nucleocapsid protein-mediated dimerization of avian leukosis virus rna. | the avian leukosis virus (alv) belongs to the alpha group of retroviruses that are widespread in nature. the 5'-untranslated region of alv genome contains the l3 element that is important for virus infectivity and the formation of an unstable rna dimer in vitro. the l3 sequence is predicted to fold into a long stem-loop structure with two internal loops and an apical one. phylogenetic analysis predicts that the l3 stem-loop is conserved in alpharetroviruses. furthermore, a significant selection ... | 2007 | 17706668 |
| assessing tumor progression factors by somatic gene transfer into a mouse model: bcl-xl promotes islet tumor cell invasion. | tumors develop through multiple stages, implicating multiple effectors, but the tools to assess how candidate genes contribute to stepwise tumor progression have been limited. we have developed a novel system in which progression of phenotypes in a mouse model of pancreatic islet cell tumorigenesis can be used to measure the effects of genes introduced by cell-type-specific infection with retroviral vectors. in this system, bitransgenic mice, in which the rat insulin promoter (rip) drives expres ... | 2007 | 17941720 |
| influence of strain, dose of virus, and age at inoculation on subgroup j avian leukosis virus persistence, antibody response, and oncogenicity in commercial meat-type chickens. | the effects of viral strain, viral dose, and age of bird at inoculation on subgroup j avian leukosis virus (alv j) persistence, neutralizing antibody (vnab) response, and tumors were studied in commercial meat-type chickens. chickens were inoculated on the fifth day of embryonation (5 ed) or on day of hatch (doh) with either 100 or 10,000 50% tissue-culture infective dose (tcid50) of one of three alv j strains, namely adol hcl, adol 6803, or adol 4817. at 1, 3, 7, 11, 15, 19, 23, 27, and 32 wk p ... | 2007 | 17992933 |
| development of a polymerase chain reaction to differentiate avian leukosis virus (alv) subgroups: detection of an alv contaminant in commercial marek's disease vaccines. | avian leukosis viruses (alvs) are common in many poultry flocks and can be detected using an enzyme-linked immunosorbent assay or any other test designed to identify p27, the group-specific antigen located in gag. however, endogenous retroviruses expressing p27 are often present and can be confused with exogenous alvs. a more specific and informative assay involves targeting the variable envelope glycoprotein gene (gp85) that is the basis for dividing alvs into their different subgroups. we desi ... | 2007 | 17992923 |
| telomerase reverse transcriptase expression elevated by avian leukosis virus integration in b cell lymphomas. | simple retroviruses induce tumors by integrating into the host genome, activating cellular oncogenes and micrornas, or inactivating tumor suppressor genes. the identification of these genes elucidates molecular mechanisms of tumorigenesis. in this study, we identified avian leukosis virus (alv) proviral integration sites in rapid-onset b cell lymphomas arising <12 weeks after infection of chicken embryos. by using inverse pcr, 28 unique viral integration sites were identified in rapid-onset tumo ... | 2007 | 18024587 |
| detection and localization of naturally transmitted avian leukosis subgroup j virus in egg-type chickens by in situ pcr hybridization. | avian leukosis virus (alv) subgroup j (alv-j) is an exogenous alv and causes myeloid leukosis in meat-type chickens. we have previously reported the isolation and identification of alv-j in commercial layer flocks from 12 farms in northern china. in this report, we further characterized this virus by in situ polymerase chain reaction (pcr) hybridization in various affected organs of chickens from six of the 12 farms. a routine method for hybridization of nucleic acid uses radioactive probe, such ... | 2007 | 18045338 |
| distribution of viral antigen gp85 and provirus in various tissues from commercial meat-type and experimental white leghorn line 0 chickens with different subgroup j avian leukosis virus infection profiles. | immunohistochemistry and polymerase chain reaction (pcr) were used to test for the presence of avian leukosis virus (alv) j viral antigen gp85 and proviral dna, respectively, in various tissues (adrenal gland, bone marrow, gonad, heart, kidney, liver, lung, pancreas, proventriculus, sciatic nerve, spleen, and thymus). tissues were collected from 32-week-old commercial meat-type and avian disease and oncology laboratory experimental white leghorn line 0 chickens with the following different infec ... | 2008 | 18202944 |
| trim e3 ligases interfere with early and late stages of the retroviral life cycle. | members of the tripartite interaction motif (trim) family of e3 ligases have been shown to exhibit antiviral activities. here we report a near comprehensive screen for antiretroviral activities of 55 trim proteins (36 human, 19 mouse). we identified approximately 20 trim proteins that, when transiently expressed in hek293 cells, affect the entry or release of human immunodeficiency virus 1 (hiv), murine leukemia virus (mlv), or avian leukosis virus (alv). while trim11 and 31 inhibited hiv entry, ... | 2008 | 18248090 |
| molecular epidemiology of avian leukosis virus subgroup j and evolutionary history of its 3' untranslated region. | avian leukosis subgroup j (alv-j) causes a variety of tumors and mortality in meat-type chickens. since its discovery in the late 1980s, alv-j has spread to breeding stock produced by most primary breeding companies of north america, the european union, and asia. alv-j seems to have been eradicated from elite breeding stock produced by most primary breeders, albeit alv-j still circulates in some commercial poultry. this study was undertaken to examine the molecular epidemiology and evolution of ... | 2007 | 18251406 |
| receptor-induced thiolate couples env activation to retrovirus fusion and infection. | according to current models of retrovirus infection, receptor binding to the surface subunit (su) of the envelope glycoprotein (env) triggers a conformational change in the transmembrane subunit (tm) that mediates virus fusion to cell membranes. to understand how this occurs, we investigated the role of the receptor tva in avian leukosis virus-a (alv-a) infection. we find that tva binding induced the formation of a reactive thiolate on cys38 (cys38-s- in su. both chemical and genetic inactivatio ... | 2007 | 18260686 |
| quantitative evaluation of dna methylation patterns for alve and tvb genes in a neoplastic disease susceptible and resistant chicken model. | chicken endogenous viruses, alve (avian leukosis virus subgroup e), are inherited as ltr (long terminal repeat) retrotransposons, which are negatively correlated with disease resistance, and any changes in dna methylation may contribute to the susceptibility to neoplastic disease. the relationship between alve methylation status and neoplastic disease in the chicken is undefined. white leghorn inbred lines 7(2) and 6(3) at the adol have been respectively selected for resistance and susceptibilit ... | 2008 | 18320050 |
| [sequence analysis for the complete provial genome of endogenous avian leukosis virus strain sd0501]. | the genomic dna extracted from chicken embryo fibroblasts (cef) of spf chickens from three chicken farms was used as template to amplify the alv proviral dna by pcr with four pairs of primers, high positive detection rates of gag - gene (29/46), pol - gene (27/46), env - gene (24/46) and ltr fragment (31/46) were achieved. eight continuous and overlapping fragments were amplified from one dna sample with 8 pairs of primers according to published sequences, then cloned into the ta vector and se q ... | 2008 | 18320823 |
| molecular characterization of full-length mlv-related endogenous retrovirus chirv1 from the chicken, gallus gallus. | we report the first full-length sequence of an endogenous retrovirus from the genome of domestic chicken, that is not related to the avian leukemia viruses (alv). this retrovirus, designated chirv1, clusters with murine leukemia virus (mlv)-related retroviruses and hence is the first complete gammaretrovirus from the genome of a bird. nevertheless it is not related to exogenous mlv-related retroviruses infecting chicken. the provirus is 9133 bp long and contains 90%-identical ltrs as well as rea ... | 2008 | 18440041 |
| [dimerization of short rna fragments from avian leukosis virus as revealed with 2-aminopurine fluorescence]. | the dimerization of genomic retroviral rna is well studied for several groups of viruses, the dimerization of human immunodeficiency (hiv) rna being investigated in more detail. regions of dimerization apparently involve the short sequences rna which are directly responsible for the formation of two type dimers: kissing loop-loop (kd) and linear (ld). the 5'-end sequences from rna avian viruses, where the dimers are basically formed, considerably differ from those of hiv. however, as it was desc ... | 2008 | 18389630 |
| [preparation and characterization of monoclonal antibodies against m2 protein of avian influenza virus]. | to prepare and characterize the monoclonal antibodies against m2 protein of avian influenza virus (aiv). | 2008 | 18466706 |
| prevalence of fowl glioma-inducing virus in chickens of zoological gardens in japan and nucleotide variation in the env gene. | fowl glioma-inducing virus (fgv), which belongs to subgroup a of avian leukosis virus (alv), is tumorigenic in the nervous system. in a zoological garden in japan, approximately 40% of chickens, including japanese fowls, were infected with fgv. because this zoological garden plays a role as a major supplier of japanese fowl for other zoological gardens, fgv infection is suspected to have spread among ornamental chickens. in this study, the prevalence of the disease was examined in a total of 129 ... | 2008 | 18525168 |
| rhabdomyosarcoma of the pectoral muscles of a free-living european robin (erithacus rubecula). | an adult free-living european robin (erithacus rubecula) with a large, firm, subcutaneous mass on the pectoral muscle was examined. the bird was unable to fly and died spontaneously. necropsy revealed a yellowish, bilobate mass almost completely replacing the pectoral muscles with extensive osteolysis of the keel bone. histopathology revealed a poorly demarcated, highly cellular sarcomatous tumour with metastases to the lungs, pulmonary blood vessels and heart. immunohistochemistry was negative ... | 2008 | 18568658 |
| a recombinant avian leukosis virus associated with fowl glioma in layer chickens in japan. | fowl glioma is characterized by multiple nodular growth of astrocytes, and fowl glioma-inducing virus belonging to avian leukosis virus has been isolated from japanese bantam as a causal agent. subcutaneous neoplasms of the head and neck have been reported in layer chickens since 2003 in japan, and fowl glioma concurred in these affected layers. in the present study, the histopathology of 240 layers, including 18 layers with subcutaneous neoplasms and 222 layers kept with the affected layers, wa ... | 2008 | 18393089 |
| differentiation of legume carlaviruses based on their biochemical properties. | nucleic acids of alfalfa latent virus (alv), pea streak virus (psv), and red clover vein mosaic virus (rcvmv) were hydrolyzed by pancreatic rnase but not by dnase. alv and psv each had one single-stranded rna of 38.0 and 37.6 s, respectively, whereas two single-stranded rnas of 39.1 and 12-15 s were found in the rcvmv preparations. the average apparent molecular weights obtained by sedimentation and electrophoresis of formalinized alv-rna, psv-rna, and the large rna of rcvmv were 2.45, 2.55, and ... | 1977 | 18625493 |
| endogenous viral genes influence infection with avian leukosis virus. | the influence of endogenous viral (ev) genes on avian leukosis virus (alv) infection was studied in alv-free white leghorn chickens exposed to chicks from alv shedding dams. the study included four lines, each segregating for one ev gene, one line free of ev genes, and four commercial stocks segregating for a number of ev genes. genes ev12 and ev21 that produce the complete endogenous virus were associated with significant reductions in antibody response to alv. in commercial stocks with ev21 in ... | 1995 | 18645822 |
| molecular characterization of three recombinant isolates of avian leukosis virus obtained from contaminated marek's disease vaccines. | three natural recombinant avian leukosis viruses (alv; pdrc-1039, pdrc-3246, and pdrc-3249) expressing a subgroup a gp85 envelope protein and containing long terminal repeats (ltr) of endogenous alv-e viruses were isolated from contaminated commercial marek's disease vaccines, cloned, and completely sequenced. their full genomes were analyzed and compared with representative strains of alv. the proviral dna of all three isolates displayed 99.3% identity to each other, suggesting a possible commo ... | 2008 | 18646453 |
| an outbreak of lymphomas in commercial broiler breeder chickens vaccinated with a fowlpox vaccine contaminated with reticuloendotheliosis virus. | gross and microscopic examinations of affected tissues from chickens of two commercial broiler breeder flocks aged 27 and 31 weeks revealed lesions of visceral lymphomas with bursal involvement in some chickens. reticuloendotheliosis virus (rev), but not avian leukosis virus (alv), was isolated from blood of affected chickens. furthermore, dna extracted from tumours tested positive for rev, but not for alv or marek's disease virus by polymerase chain reaction (pcr) test. attempts to determine th ... | 1996 | 18645835 |
| some observations on naturally occurring neoplasms of domestic fowls in the state of victoria, australia (1977-87). | in the 10 years to november 1987, 33 different types of naturally occurring neoplasms were diagnosed in 2281 domestic fowls submitted for necropsy examination. the most prevalent type was lymphoma (1825/2281 = 80%) including two cases in chickens from a flock free from marek's disease virus, exogenous avian leukosis viruses and reticuloendotheliosis virus; the remaining lymphomas were diagnosed on gross and/or histological criteria as marek's disease (1069) or lymphoid leukosis (754). of the non ... | 1996 | 18645870 |
| development of an alloantiserum (r2) that detects susceptibility of chickens to subgroup e endogenous avian leukosis virus. | an alloantiserum, termed r2, specifically agglutinates red blood cells (rbc) from line 100b chickens that are susceptible to avian leukosis viruses (alv) belonging to subgroups b and e, but does not agglutinate rbc from congenic inbred line 7(2) chickens that are resistant to alv b and e. the r2 antigen was also detected on lymphocytes and thrombocytes. using chickens from a special cross, it was found that r2 reactivity requires that the chickens must: (1) be susceptible to infection by alv-e; ... | 1996 | 18645878 |
| endogenous leukosis viral antigen in eggs from meat-type chickens on an avian leukosis virus eradication programme. | in an effort to eliminate exogenous avian leukosis virus (alv) from a susceptible population, albumen of one egg per hen from each of four generations was tested by elisa for group-specific antigen (gsa) of leukosis/sarcoma viruses. from 1510 to 2099 hens were tested in each generation. hens were not used as breeders if optical density readings for gsa were 0.4 or greater. despite this procedure, there was no appeciable change in the occurrence of gsa in eggs from one generation to the next and ... | 1992 | 18670937 |
| effects of age at infection with serotype 2 marek's disease virus on enhancement of avian leukosis virus-induced lymphomas. | inoculation of susceptible, 15i5 x 7i chickens with serotype 2 marek's disease virus (mdv) at various ages had no influence on the development of avian leukosis virus (alv)-induced viraemia or antibody in chickens infected with alv and turkey herpesvirus (hvt) at hatch. however, the incidence of alv-induced lymphoma (ll) was significantly higher in chickens infected with alv and hvt at hatch and inoculated with serotype 2 mdv up to 6 weeks of age than in chickens receiving serotype 2 mdv at 8 to ... | 1993 | 18671041 |
| feather pulp as a source of antibody to avian viruses. | feather pulp from white leghorns that had been inoculated with the rav-1 strain of avian leukosis virus (alv) was tested for antibody by elisa. in an elisa on three feather pulps and serum from each of four inoculated chickens, there was a highly significant correlation between antibody levels in feather pulp (1 pulp per 800 mul of buffer) and a 1:500 dilution of serum. also based on elisa, there were highly significant correlations between levels of maternal and actively acquired antibody to ne ... | 1992 | 18670946 |
| detection of retrovirus sequences in budgerigars with tumours. | renal tumours are a common neoplastic disease of budgerigars. although a retro-virus has been implicated as the aetiological agent, there is no definitive proof for this hypothesis. sixteen birds suspected to have renal tumours were examined in an attempt to elucidate the possible role of retroviruses. thirteen birds had renal tumours and the majority of these birds showed abdominal enlargement and paresis. renal masses were detected by radiography in nine birds. post-mortem examination confirme ... | 1993 | 18670995 |
| detection of reticuloendotheliosis virus infection using the polymerase chain reaction. | the polymerase chain reaction (pcr) was shown to be a sensitive and useful method for detection of infection by members of the group of avian reticuloendotheliosis virus (rev). genomic dna extracted from chick embryo fibroblasts (cefs), blood and tumours of chickens experimentally infected with the spleen necrosis virus (snv) strain of rev was used as the target for chain elongation. deoxyoligonucleotide primers that encompass a portion of the unique 3', repeat and unique 5' region of the long t ... | 1993 | 18671039 |
| avian leukosis virus infection and shedding in brown leghorn chickens treated with corticosterone or exposed to various stressors. | increased levels of plasma corticosterone following administration of the hormone at 1, but not 2, weeks after exposure to avian leukosis virus (alv) at hatching, significantly increased cloacal shedding of alv in chickens that lacked maternal antibody (mab) to alv. exposure of 2-week-old chickens, which had been exposed to virus at hatching, to heat- or cold-stress for 21 days had no effect on alv infection and shedding. mab significantly reduced or eliminated shedding in treated as well as in ... | 1989 | 18679860 |
| isolation of marek's disease virus from japanese quail with lymphoproliferative disease. | sixty-one japanese quail from eight flocks with problems of recurring outbreaks of lymphoproliferative diseases resembling marek's disease (md), were examined aetiologically. gross lymphomatous lesions were seen in 17 of the quail and 11 out of 56 quail had md virus (mdv) feather tips antigens. mdv antibody was detectable in only one of 22 quail. none of 9 quail had antibodies against reticuloendotheliosis virus (rev). no mdv was isolated from the total 42 materials of quail using cell culture t ... | 1990 | 18679919 |
| response of meat-type chickens to infection with rav-1 avian leukosis virus. | meat-type and white leghorn chickens were inoculated with the rav-1 strain of avian leukosis virus at 1 day of age and the severity of infection was assessed by clinical illness, haematology and post-mortem findings. the following were examined from selected birds: histological section for chronic mononuclear myocarditis, immunohistochemically-stained sections of myocardium, spleen, bursa of fabricius and kidney for group-specific viral antigen, and ultrathin sections of these tissues for virus ... | 1991 | 18680061 |
| feather pulp organ cultures for assessing host resistance to infection with avian leukosis-sarcoma viruses. | the purpose of this study was to improve in vitro procedures for detecting cellular resistance to the avian leukosis-sarcoma group of viruses. four feather pulp organ cultures (fpoc) were prepared from each chicken by placing pulp squeezed from feathers in wells of microtitre plates that contained culture medium. two of the four fpoc were inoculated with rous sarcoma virus (rsv) of subgroup a and 5 to 6 days later the fluids from all four cultures were assayed for virus by inoculating chicken em ... | 1987 | 18766632 |
| comparative response of turkeys and chickens to avian lymphoid leukosis virus. | response of turkeys and 151(5)x7(1) chickens to prenatal or neonatal inoculation with the avian leukosis virus rav-1 was compared. virus-inoculated turkeys and chickens developed viraemia and antibody to. rav-1. many of the chickens remained persistently viraemic through the duration of the experiment, whereas in turkeys viraemia was transient. circulating antibodies were detected earlier in turkeys than in chickens. inoculation of turkeys with rav-1 resulted in a high incidence of inflammatory ... | 1983 | 18766780 |
| neoplasms in budgerigars (melopsittacus undulatus): clinical, pathomorphological and serological findings with special consideration of kidney tumours. | according to findings of others and to our own investigations, kidney tumours represent a remarkably high proportion of all tumours in budgerigars. therefore, 74 budgerigars, clinically suspicious for abdominal tumours, were analysed individually by monitoring clinical signs, gross lesions, histology, the expression of the group-specific (gs) antigen of avian leukosis virus (alv), the expression of immunoglobulins m and g, and the distribution of age and tumour incidence. lameness and abdominal ... | 1983 | 18766792 |
| the use of elisa for detection of exogenous and endogenous avian leukosis viral antigens in basic breeding flocks. | an enzyme-linked immunosorbent assay (elisa) for avian leukosis/ sarcoma virus (alv) group-specific (gs) antigens was used to study the identification of hens which congenitally excrete exogenous alv. the sensitivity of this assay was compared with that of the phenotypic mixing test (pmt) and the direct complement fixation test (cft) by testing limiting dilutions of purified avian myeloblastosis virus (amv), embryo homogenates and albumens. about 0.4 ng/ml of purified amv protein could be detect ... | 1983 | 18766804 |
| marek's disease in turkeys: the induction of lesions and the establishment of lymphoid cell lines. | the inoculation of turkeys with large doses of a virulent strain of marek's disease virus (ga strain), but not of two other virulent strains (hprs-16 and jm), was found to induce a disease resembling marek's disease of the chicken. the most prominent lesions were lymphocytic leukaemia and lymphoid and reticular hyperplasia in the spleen and the liver. these developed after a prolonged latent period and the early histological changes (lymphoid cell destruction and reticuloendothelial cell hyperpl ... | 1984 | 18766837 |
| identification of avian leukosis virus shedding hens. comparison of alv gs-antigen levels in various test samples. | various materials from two white leghorn basic breeder flocks were tested by the enzyme-linked immunosorbent assay (elisa), the complement fixation test (cft) for detection of avian leukosis/sarcoma virus (alv) group-specific (gs) antigens and the phenotypic mixing test (pmt) to compare the applicability of these techniques for the identification of hens which congenitally excrete exogenous alv. the predictive value of each test was evaluated on the basis of association between alv gs-antigen de ... | 1984 | 18766847 |
| viral aetiology of haemangiosarcoma outbreaks among layer hens. | outbreaks of neoplastic disease defined as haemangiosarcoma occurred among layer flocks of chickens in israel. the disease caused bleeding tumours in the skin and internal organs of young layers, followed by anaemia, cessation of egg production and high mortality up to 20%. avian leukosis virus was isolated from tumour cells which contain several viral dna copies integrated in the cell genome. the isolated virus induced haemangiosarcomas in more than 30% of birds inoculated on the day of hatchin ... | 1984 | 18766881 |
| application of monoclonal antibodies in the avian leukosis virus gs-antigen elisa. | five hybridoma cell lines which secrete antibodies to avian leukosis/ sarcoma (alv) group-specific (gs) antigens (gag gene products) have been established. the hybrid cells resulted from fusion of p3/x63-ag8.653 myeloma cells with splenocytes of balb/c mice which had been immunised with purified avian myeloblastosis virus (amv). screening of supernatant fluids was performed by an indirect double antibody sandwich enzyme-linked immunosorbent assay (idas-elisa) and the immunoelectroblotting techni ... | 1985 | 18766897 |
| application of monoclonal antibodies in the dutch avian leukosis control programme. | comparative testing with series of albumen samples obtained from seven dutch poultry flocks was performed for avian leukosis virus group-specific antigen (alv-gsa) by complement fixation test (cft) and by a double antibody sandwich enzyme-linked immunosorbent assay (das-elisa) employing selected monoclonal antibodies directed to different alv-p27 epitopes. the higher sensitivity for alv-gsa detection of the das-elisa resulted in increased scores of alv-shedding hens in all seven flocks. relative ... | 1985 | 18766935 |
| variation in tolerance induction and oncogenicity due to strain of avian leukosis virus. | chickens were inoculated as embryos or orally at hatching with various doses of four strains of avian leukosis virus (alv) subgroup a (rav-1, rpl40, rpl41 and rpl42). viraemia, antibody and tumours in chickens of various groups were compared; alv shedding was determined, but only in chickens inoculated with virus at hatching. results indicate that 95% to 100% of chickens embryonally inoculated with 105 infectious units of virus were viraemic at hatching, regardless of the strain of virus used. h ... | 1987 | 18766653 |
| lymphoreticular tumour in pen-raised pheasants associated with a reticuloendotheliosis like virus infection. | an outbreak of a lymphoproliferative disease in pheasants is described. nodular or diffuse tumours were found on the head and in various internal organs. the lesions consisted of undifferentiated lymphoreticular cells. a typical c-type virus, similar to reticuloendotheliosis virus was isolated in tissue culture. however, this virus particle could not be seen in the tumours. the isolate is antigenically related to the reticuloendotheliosis group of viruses. typical reticuloendotheliosis was induc ... | 1983 | 18766763 |
| endogenous viral genes in a slow-feathering line of white leghorn chickens. | endogenous viruses related to avian leukosis viruses were characterised in three sire families of slow-feathering white leghorns. progeny released infectious endogenous virus when extracts were tested on subgroup e susceptible fibroblasts. restriction fragment length polymorphisms (rflps) indicated germline transmission of ev1, ev5, ev21 and a hitherto unreported locus ev22 among three sire families. the association of ev21 with the release of infectious endogenous virus precluded phenotypic cha ... | 1986 | 18766541 |
| age related resistance to avian leukosis virus. ii. influence of age at inoculation on mortality and congenital transmission. | six age groups of specified pathogen free white leghorn chickens housed in the same filtered air, positive pressure building, were inoculated at 1 day, 2, 4, 6, 8 and 10 weeks of age respectively, with a mixture of leukosis viruses of subgroups a and b. birds which died during the experiment were examined for gross and microscopical lesions. the incidence of lymphoid leukosis (ll) in the various groups was inversely proportional to the age of first virus exposure, le., mortality was 62.5% in the ... | 1982 | 18770176 |
| role of cell-mediated immunity (cmi) in chickens inoculated with avian leukosis/sarcoma virus. | immunosuppression of chickens infected in ovo with avian leukosis virus (rav-1) by the injection of antilymphocyte serum (als) did not significantly (p > 0.05) alter the incidence or distribution of lesions in chickens between 3 and 6 months of age as compared to control groups. antilymphocyte serum treatment of rous sarcoma virus [rsv (rav-2)]-infected chickens significantly (p < 0.05) inhibited tumour regression and enhanced tumour metastasis. it was concluded that cell-mediated immunity was n ... | 1977 | 18770324 |
| lymphoproliferative disease of turkeys. ii. experimental transmission and aetiology. | the clinical and pathological features of a previously reported lympho-proliferative disease of turkeys were reproduced by inoculation of 4-week-old poults, and spread to in contact turkeys was demonstrated. from studies on the development of the lesions in inoculated turkeys, it was possible to assay the causative agent based on microscopic examination of early lesions. poults were more susceptible to inoculation when 4 weeks old than to inoculation at 1 day old, and different strains of turkey ... | 1978 | 18770366 |
| age related resistance to avian leukosis virus. iii. infectious virus, neutralising antibody and tumours in chickens inoculated at various ages. | viraemia and neutralising antibodies were determined in chickens of six age-groups following inoculation with leukosis virus of subgroups a and b at the age of 1 day, and 2, 4, 6, 8 and 10 weeks respectively. the birds were kept in a filtered air positive pressure (fapp) house. a seventh age-group, accommodated in a separate fapp-house, was used as an untreated control. serum samples, received at biweekly intervals between 1-17 weeks post-inoculation, from birds of the groups inoculated at 4, 6, ... | 1982 | 18770194 |
| detection of avian leukosis virus with the elisa system: evaluation of conjugation methodology and comparison of sensitivity with the phenotypic mixing test in commercial layer flocks. | conjugates of horseradish peroxidase with rabbit igg antibody against gs antigen (p27) of avian myeloblastosis virus were prepared using glutaraldehyde and periodate methods of coupling. conjugates were evaluated for the detection of gs antigen of avian leukosis and sarcoma viruses in the elisa system and the periodate conjugate was found to be superior. with an elisa based on a periodate conjugate it was possible to detect 5 x 10(3) iu of leukosis virus propagated in cell culture. comparisons b ... | 1982 | 18770224 |
| age-related resistance to avian leukosis virus. i. influence of age at exposure on mortality and congenital transmission. | groups of white leghorn chickens were inoculated at 1 day and at 2, 4, 6 and 8 weeks of age respectively with a mixture of leukosis viruses of subgroups a and b. the five infected groups were kept in a filtered air positive pressure house. a sixth group was accommodated separately in a similar house as a control. all birds which died or were removed were subjected to pathohistological examination; diagnosis of lymphoid leukosis was made upon either gross lesions plus microscopical lesions or mic ... | 1980 | 18770263 |
| occurrence of different subgroups of avian leukosis virus in finnish poultry. | ten finnish breeding flocks were investigated for occurrence of avian leukosis virus and antibodies. the results show that field isolates representing all 4 main subgroups, a, b, c, and d, of avian leukosis virus have been identified. antibodies to these subgroups are widespread in the country. within 5 of the flocks antibody response to all 4 subgroups was found simultaneously, and there were individual chickens that carried antibodies against 2, 3, and in 2 cases, even, all 4 subgroups at the ... | 1974 | 18777270 |
| an antigen in normal avian cells which confuses virological and serological tests. | a cytoplasmic antigen was detected by fluorescent antibody tests in normal lymphoid and fibroblastic cells from chickens and other avian species when explanted and grown in culture. cells of the bursa of fabricius were consistently positive but cells of a proportion of thymus, spleen, bone marrow, buffy coat and embryo fibroblast cultures also were positive. eight of 19 fluorescein-conjugated chicken sera prepared for other studies on a variety of avian pathogens had antibody against the antigen ... | 1975 | 18777316 |
| development of an endogenous virus-free line of chickens susceptible to all subgroups of avian leukosis virus. | primary chicken embryo fibroblasts (cef) from special specific pathogen-free chicken lines are used for detection of contamination of adult or embryonic tissues, meconium, or tissue culture fluids with avian leukosis viruses (alv). the suitability and efficiency of such tests depend on the susceptibility of cef to the various subgroups of exogenous as well as endogenous alv. the ideal cef for such tests should be not only susceptible to all retroviruses, but also free of endogenous viruses so th ... | 2008 | 18939628 |
| survey of endogenous virus and tvb* receptor status of commercial chicken stocks supplying specific-pathogen-free eggs. | endogenous avian leukosis virus (alve) and the alve receptor (tvb*s1) status of six commercial chicken lines supplying specific-pathogen-free eggs were analyzed. all commercial chicken lines are certified free of the avian leukosis virus (alv) by screening for expression of the p27 protein using the standard enzyme-linked immunosorbent assay. the commercial chicken lines a, e, and f contained replication competent alve inserts. line a was fixed for alve21, and lines e and f were segregating for ... | 2008 | 18939631 |
| structure of the capsid amino-terminal domain from the betaretrovirus, jaagsiekte sheep retrovirus. | jaagsiekte sheep retrovirus is a betaretrovirus and the causative agent of pulmonary adenocarcinoma, a transmissible lung tumour of sheep. here we report the crystal structure of the capsid amino-terminal domain and examine the self-association properties of jaagsiekte sheep retrovirus capsid. we find that the structure is remarkably similar to the amino-terminal domain of the alpharetrovirus, avian leukosis virus, revealing a previously undetected evolutionary similarity. examination of capsid ... | 2009 | 19007792 |
| [the identification and sequence analysis of alv-j isolated from layers]. | two avian leukosis viruses of subgroup j (alv-j) were isolated from layers by inoculating the sample into chicken embryo fibroblast (cef) cells and by indirect fluorescent assay (ifa) with alv-j specific monoclonal antibody je-9. sequence comparison indicated the gp85 identities were only in the ranges of 83.4%-87.3% compared with five international reference strains and 86.4%-89.6% compared with eight chinese strains isolated from white meat-type chickens. the gp37 identities were in the range ... | 2008 | 19035326 |
| isolation of acutely transforming subgroup j avian leukosis viruses that induce erythroblastosis and myelocytomatosis. | avian leukosis virus of subgroup j (alv-j), isolated in the late 1980s, predominantly causes myelocytic myeloid leukosis in meat-type chickens. in the past few years, we have observed the occurrence of lesions indicative of erythroblastosis in alv-j-infected flocks and, in this paper, we report the isolation of alv-j strains from such flocks. three of these isolates were acutely transforming viruses, as shown by their ability to transform bone marrow cell cultures. the bone marrow cultures trans ... | 2000 | 19184822 |
| isolation and identification of avian leukosis viruses: a review. | avian leukosis virus (alv) is the most common naturally occurring avian retrovirus that can cause a variety of neoplastic disease conditions in chickens. in addition to causing neoplasia, alv is known to be associated with reduced productivity and other production problems in affected flocks. biological and molecular assays for the detection of alv are very useful in identification and classification of new isolates, safety testing of vaccines and in testing pathogen-free and other breeder flock ... | 2000 | 19184848 |
| relationship between egg size and subgroup j avian leukosis virus in eggs from broiler breeders. | hatching eggs from three broiler breeder flocks that had experienced losses from myeloid leukosis were tested for infection with avian leukosis virus of subgroup j (alv-j). sufficient eggs were positive in two flocks to relate infection to egg weight. allantoic fluid, embryonic tissue and yolk were collected after 18 days of incubation. the albumen and allantoic fluid were tested by enzyme-linked immunosorbent assay (elisa) for group-specific (gs) antigen and all specimens were inoculated onto c ... | 2000 | 19184859 |
| amyloid a amyloidosis in non-infected and avian leukosis virus-c persistently infected inbred ducks. | the breeding history of the first inbred strain of khaki campbell ducks is presented. the genetic homogeneity of this strain was tested on the basis of serum amyloid a (saa) polymorphism and it was established that it harbours only the saa allele a, which is expressed in liver, lung and bursa of fabricius tissues. pathogenic changes in control and avian leukosis virus-c (alv-c) persistently infected ducks were evaluated during the period spanning 1 to 10 months after hatching. in both groups, aa ... | 2001 | 19184871 |
| innovation and discovery: the application of nucleic acid-based technology to avian virus detection and characterization. | polymerase chain reaction (pcr)-based approaches to the detection, differentiation and characterization of avian pathogens continue to be developed and refined. the pcrs, or reverse transcriptase-pcrs, may be general, designed to detect all or most variants of a pathogen, or to be serotype, genotype or pathotype specific. progress is being made with respect to making nucleic acid approaches more suitable for use in diagnostic laboratories. robotic workstations are now available for extraction of ... | 2001 | 19184952 |
| reduction of horizontal transmission of avian leukosis virus subgroup j in broiler breeder chickens hatched and reared in small groups. | transmission of avian leukosis virus, subgroup j (alv-j), from donor chickens inoculated as embryos to simulate congenital infection to uninfected hatchmates was studied in two strains of commercial broiler breeder chickens. chicks of two commercial lines free of alv-j became infected when hatched (1/2 lots positive) or reared (8/8 lots positive) in direct physical contact with alv-j-infected donors. infection also occurred when chicks were exposed in the hatchery to alv-j-infected donors by clo ... | 2001 | 19184958 |
| avian leukosis virus subtype j in ovo -infected specific pathogen free broilers harbour the virus in their feathers and show feather abnormalities. | in the present paper, abnormal feather development associated with an in ovo avian leukosis virus (alv) subgroup j infection in specific pathogen free broilers is reported. a description of gross lesions is given, together with the results of light microscopic, immunohistochemical and ultrastructural studies to further elucidate the characteristics of the feather pathology and to assess the presence of alv subtype j in broiler feathers. the feather lesions found, which were mainly restricted to ... | 2001 | 19184962 |
| isolation of acutely transforming subgroup j avian leukosis viruses that induce erythroblastosis and myelocytomatosis. | avian leukosis virus of subgroup j (alv-j), isolated in the late 1980s, predominantly causes myelocytic myeloid leukosis in meat-type chickens. in the past few years, we have observed the occurrence of lesions indicative of erythroblastosis in alv-j-infected flocks and, in this paper, we report the isolation of alv-j strains from such flocks. three of these isolates were acutely transforming viruses, as shown by their ability to transform bone marrow cell cultures. the bone marrow cultures trans ... | 2000 | 19184842 |