Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| mechanism of c-erbb transduction: newly released transducing viruses retain poly(a) tracts of erbb transcripts and encode c-terminally intact erbb proteins. | we have previously shown that avian leukosis virus (alv) induces erythroblastosis by insertional activation of the c-erbb gene. in 25% of the alv-induced leukemic samples we have analyzed, acute retroviruses that have captured the activated erbb oncogene were released. the unusually high frequency at which erbb transduction occurs makes this an ideal system for studying the mechanism of oncogene transduction. in addition, these leukemic samples provide a rich source for the isolation of novel er ... | 1988 | 2897475 |
| formation of a transformed follicle is necessary but not sufficient for development of an avian leukosis virus-induced lymphoma. | avian leukosis virus (alv) infection of susceptible chickens induces bursal lymphomas after a latent period of several months. the clonal development of these b-cell tumors is believed to be a multistep process. histopathological changes, referred to as transformed follicles, occur within the target organ soon after virus infection and may represent a proximal stage of lymphomagenesis. to establish further the significance of this lesion and its relationship to the subsequent development of lymp ... | 1985 | 2982144 |
| effects of chemically or virus-induced immunodepression on response of chickens to avian leukosis virus. | the effects of chemically or virus-induced immunodepression on the infection profile (development of viremia and antibody) and shedding of avian leukosis virus (alv) were studied in progeny chickens of experimental or commercial breeder flocks. chickens were infected with alv subgroup a by contact at hatching and by oral inoculation at 4-5 weeks of age. in the first experiment, chickens were inoculated with a virulent strain of infectious bursal disease virus (ibdv) at 1 day or 6 weeks of age. i ... | 1985 | 2985037 |
| high-frequency transduction of c-erbb in avian leukosis virus-induced erythroblastosis. | twenty-one cases of rous-associated virus type 1-induced erythroblastosis have been analyzed for novel restriction endonuclease fragments of c-erbb. twenty of the erythroleukemias contained novel c-erbb fragments; 10 of these were found to contain a proviral insertion in c-erbb, and 10 were found to have a new transduction of c-erbb. each of the proviral insertions was in the same transcriptional orientation as c-erbb, and most appeared to have retained both long terminal repeats as well as 5' v ... | 1985 | 2985798 |
| responses of chickens lacking or expressing endogenous avian leukosis virus genes to infection with exogenous virus. | line 0 chickens that lack endogenous viral (ev) genes and 15i5 x 7 chickens that carry and express ev genes were inoculated with the avian leukosis virus, rav-1, at 1 day of age or as embryos, and maintained to 70 days of age. comparable uninoculated controls were also kept. most of the day-old inoculated chickens developed antibody by 70 days, but as expected, most of the embryo inoculated chickens remained viremic. major differences in response between the lines were only noted after day-old i ... | 1985 | 2986085 |
| insertional activation of c-myc by reticuloendotheliosis virus in chicken b lymphoma: nonrandom distribution and orientation of the proviruses. | chicken syncytial virus, a member of the reticuloendotheliosis virus family, can induce chicken b lymphomas indistinguishable from those caused by avian leukosis virus. previously, we have demonstrated that the chicken syncytial virus proviruses in these tumors are linked to the proto-oncogene c-myc. we have now determined the arrangement of chicken syncytial virus proviruses in 22 tumors. the results indicate that these proviruses, without exception, are integrated upstream from the second c-my ... | 1985 | 2987538 |
| variation in susceptibility to avian sarcoma viruses and expression of endogenous avian leukosis virus antigens in specific pathogen-free chicken lines. | five lines of chickens maintained as specific pathogen-free flocks in australia were characterized in relation to endogenous antigens and endogenous avian leukosis virus expression. embryos of line n were predominantly of c/e phenotype, uniformly positive for group-specific antigen and chick helper factor (gs+chf+) and 38% expressed endogenous virus at a very low titre. embryos of line m4 were uniformly of c/abe phenotype and were either gs+chf+ or gs-chf+. line w19 embryos segregated for suscep ... | 1985 | 2991436 |
| enhanced transcription of c-myc in bursal lymphoma cells requires continuous protein synthesis. | in several bursal lymphoma cell lines in which c-myc transcription is regulated by avian leukosis virus (alv) long terminal repeat (ltr) sequences, protein synthesis inhibition decreases the transcriptional activity of c-myc as well as other ltr driven viral genes. this decrease in transcription is associated with a change in the chromatin structure of c-myc, as measured by deoxyribonuclease i (dnase i) hypersensitivity, and a shift of transcription from the ltr to the normal c-myc promoter. in ... | 1985 | 2999973 |
| patterns of proviral insertion and deletion in avian leukosis virus-induced lymphomas. | sixty-eight lymphomas induced by eight different avian leukosis viruses have been analyzed on southern blots for virus-induced mutations in the chicken c-myc gene. sixty-six of the lymphomas exhibited a proviral insertion in c-myc, whereas one exhibited a new transduction of c-myc. sixty-four of the proviral insertions were in the same transcriptional orientation as c-myc. two were in the opposite transcriptional orientation. all of the insertions were upstream of the protein-coding sequences of ... | 1986 | 3001351 |
| activation of c-erbb in avian leukosis virus-induced erythroblastosis leads to the expression of a truncated egf receptor kinase. | chicken erythroblastosis caused by avian leukosis virus (alv) is thought to be mediated by activation of the c-erbb/egf receptor oncogene by a promoter-insertion mechanism. here we study the proteins expressed by two alv-induced leukemias and compare them with the avian egf receptor and with the oncogene product of avian erythroblastosis virus (v-erbb) which was shown to be a truncated egf receptor. it appears that the two leukemias express truncated egf receptors of slightly different sizes wit ... | 1985 | 3004938 |
| an enzyme-linked immunosorbent assay for detection of antibodies to exogenous avian leukosis virus. | a microplate enzyme-linked immunosorbent assay (elisa) for detecting antibodies to avian leukosis virus (alv) of subgroups a and b in infected chickens was developed with the use of rous-associated virus (rav)-1 (subgroup a) and rav-2 (subgroup b) antigens purified by sucrose-gradient centrifugation. the antigen was used for elisa after treatment with triton x-100. in the elisa, the subgroup viral antigen reacted strongly with homologous antiserum but also reacted with heterologous antiserum. te ... | 1985 | 3008696 |
| susceptibility of avian b lymphocytes to retroviral infection parallels that of fibroblasts. | the ability of conventional virus receptors to mediate infection and transformation of immature b cells by the avian leukosis virus (alv) was analyzed in chimeric chickens whose bursa of fabricius contained a mixture of b cells from subgroup a virus receptor-positive and -negative chickens. the data indicate that factors that determine resistance of fibroblasts to alv infection also apply to bursal cells and that other receptors expressed by b cells, i.e., antigen or mitogen receptors, do not in ... | 1986 | 3012871 |
| resistance of line 6(3) chickens to reticuloendotheliosis-virus-induced bursa-associated lymphomas. | chickens of lines 6(3) and 151(5) x 7(1) were inoculated with the chick syncytial strain of reticuloendotheliosis virus (rev) or with the rous-associated virus-i of avian leukosis virus (alv) at hatching. at 4, 10, 16, and 36 weeks post inoculation (pi), chickens were tested for rev- and alv-induced viremia and antibody. the incidence of rev- or alv-induced bursa-associated lymphomas in line 6(3) chickens was compared with that in line 151(5) x 7(1) chickens. inoculation of rev at hatching resul ... | 1986 | 3013782 |
| characterization of monoclonal antibodies to avian leukosis viruses. | hybridoma cell lines secreting monoclonal antibody (mca) to avian leukosis virus (alv) structural proteins p27 and p19 have been established. in an indirect enzyme-linked immunosorbent assay (elisa), mca 6al20 (igg1 isotype) reacted with rpl-40 (alv subgroup a), avian myeloblastosis virus (amv) (a mixture of subgroups a and b), rous-associated virus (rav)-2 (subgroup b), and carr-zilber strain of rous sarcoma virus (cz-rsv) (subgroup d) but not with prague strain of rsv (prc-rsv) (subgroup c) or ... | 1986 | 3015099 |
| replication-competent endogenous avian leukosis virus in commercial lines of meat chickens. | group-specific (gs)-antigen-positive egg albumen in seven commercial lines of meat chickens was found to result from the presence of endogenous avian leukosis virus (alv); these lines had resisted selection attempts to reduce the shedding rate. in two meat lines, exogenous as well as endogenous alv contributed to the gs-antigen shedding. all hens that produced gs-antigen-positive albumen transmitted endogenous alv to a high proportion of their embryos (20 to 100%). hens shedding gs-antigen to al ... | 1986 | 3015111 |
| characterization of rous sarcoma virus-related sequences in the japanese quail. | we detected sequences related to the avian retrovirus rous sarcoma virus within the genome of the japanese quail, a species previously considered to be free of endogenous avian leukosis virus elements. using low-stringency conditions of hybridization, we screened a quail genomic library for clones containing retrovirus-related information. of five clones so selected, one, lambda q48, contained sequence information related to the gag, pol, and env genes of rous sarcoma virus arranged in a contigu ... | 1986 | 3016302 |
| transmission of (ltr, v-src, ltr) without recombination with a helper virus. | we have analyzed transmission of (ltr, v-src, ltr) cryptic structure integrated in the h-19 mammalian tumor cell line. from this cell line different isolates of transforming virus were rescued in heterokaryons produced by fusion with chicken fibroblasts infected by replication-competent avian leukosis virus rav-1. one of them (f6) was used for the transformation of avian cells in the absence of the helper virus. in four transformed cell lines studied, the (ltr, v-src, ltr) structure was again in ... | 1986 | 3016994 |
| immune response to avian leukosis virus determined by the cell-mediated focus-reduction (cemfor) assay. | a cell-mediated focus-reduction (cemfor) assay was used to determine the sequential development of cell-mediated immunity to avian oncornaviruses and the nature of the cells participating in this immune reaction. peripheral blood leukocytes of leghorn chickens that had regressed rous sarcoma virus-induced tumors or were immune to avian leukosis virus had cemfor activity. the response was biphasic early in the infection. peripheral blood leukocytes from nonimmune chickens or viremic, immunologica ... | 1986 | 3018344 |
| selective integration of avian leukosis virus in different hematopoietic tissues. | hematopoietic tissues obtained from avian leukosis virus (alv)-infected hyline sc chickens were analyzed for the presence of integrated viral dna sequences. cells were prepared from bone marrow, bursa, spleen, thymus, and peripheral blood. following the removal of erythrocytes, cellular dnas from each of these tissues were examined by southern analysis. during the first few weeks of infection, dna from the bone marrow contained as many as 0.5 copies of viral dna per haploid genome. cells from th ... | 1986 | 3024400 |
| restrictions that influence avian leukosis virus-induced lymphoid leukosis. | 1986 | 3024914 | |
| the cellular homologue of the transforming gene of skv avian retrovirus maps to human chromosome region 1q22----q24. | we report the chromosomal localization of the cellular oncogene ski, the putative oncogene of the sloan-kettering viruses (skvs), a group of transforming retroviruses that had been isolated from chicken embryo cells infected with the avian leukosis virus tdb77. southern blot analysis of dna from mouse x human somatic cell hybrids with the v-ski probe established synteny with chromosome 1, but excluding the region 1pter----q21. in situ hybridization of the same probe both to human spermatocyte pa ... | 1986 | 3026737 |
| embryonic infection with the endogenous avian leukosis virus rous-associated virus-0 alters responses to exogenous avian leukosis virus infection. | we inoculated susceptible chicken embryos with the endogenous avian leukosis virus rous-associated virus-0 (rav-0) on day 6 of incubation. at 1 week after hatching, rav-0-infected and control chickens were inoculated with either rav-1 or rav-2, exogenous viruses belonging to subgroups a and b, respectively. the chickens injected with rav-0 as embryos remained viremic with exogenous virus longer and either failed to develop type-specific humoral immunity to exogenous virus or developed it later t ... | 1987 | 3027399 |
| genetic determinants of neoplastic diseases induced by a subgroup f avian leukosis virus. | two subgroup f avian leukosis viruses, ring-necked pheasant virus (rpv) and rav-61, were previously shown to induce a high incidence of a fatal proliferative disorder in the lungs of infected chickens. these lung lesions, termed angiosarcomas, appear rapidly (4 to 5 weeks after infection), show no evidence of proto-oncogene activation by proviral integration, and are not induced by avian leukosis viruses belonging to other subgroups. to identify the viral sequences responsible for induction of t ... | 1987 | 3029416 |
| an aberrant avian leukosis virus provirus inserted downstream from the chicken c-myc coding sequence in a bursal lymphoma results from intrachromosomal recombination between two proviruses and deletion of cellular dna. | a chicken bursal lymphoma, ll6, contains avian leukosis virus dna integrated 3' of the c-myc coding sequences, unlike all other examined bursal lymphomas, which have integrations 5' to c-myc. to better understand this unusual mutation, we examined a molecular clone containing the ll6 c-myc gene and determined the structure of the proviral insertion by dna sequencing. viral dna begins 575 base pairs downstream of the c-myc coding sequences within the untranslated region, disrupting the use of the ... | 1987 | 3033315 |
| [the genome of chickens free of endogenous avian leukosis-sarcoma proviruses contains sequences distantly related to rous sarcoma virus]. | line of brown leghorn chickens free of rav-o-type endogenous proviruses was obtained by selection under blot hybridization control. a set of dispersed sequences distantly related to avian leukosis virus genome was found in dna of these chickens by means of hybridization in non-stringent conditions. different restriction fragments were detected by gag, pol and env hybridization probes. | 1987 | 3033485 |
| cultivation of avian rotaviruses in chicken lymphocytes and lymphoblastoid cell lines. | avian rotavirus isolates were used to infect normal chicken spleen cells, lymphoblastoid t cell lines transformed by marek's disease virus, an avian leukosis virus-transformed b cell line, and a reticuloendotheliosis virus-transformed line, which is a pre-b, pre-t cell line. all five isolates tested were able to infect spleen cells and the three types of lymphoblastoid cell lines, suggesting that avian rotaviruses can infect both b and t cells. splenic lymphocytes were considerably less suscepti ... | 1987 | 3034208 |
| b-lymphoma induction by reticuloendotheliosis virus: characterization of a mutated chicken syncytial virus provirus involved in c-myc activation. | nondefective reticuloendotheliosis virus induces chicken bursal lymphoma in a manner similar to that of avian leukosis virus. the provirus integrates in the c-myc locus and uses a promoter insertion mechanism to activate c-myc expression. we cloned a provirus involved in c-myc activation from a b lymphoma. detailed structural characterization of this clone, including sequence determination, revealed proviral insertion at 512 base pairs preceding the second c-myc exon. the provirus has a deletion ... | 1987 | 3035210 |
| gene insertion into the chicken germ line by retroviruses. | we injected chick syncytial strain of reticuloendotheliosis virus (cs-rev) and wild type and recombinant avian leukosis virus (alv) near the blastoderm of unincubated fertilized embryos and cs-rev intra-abdominally at day of hatch, and we progeny tested the surviving alv viremic males and rev viremic males and females for transmitted viral genetic material. a number of positive progeny were identified and their deoxyribonucleic acid (dna) analyzed for restriction enzyme fragments that hybridized ... | 1986 | 3035526 |
| 5' long terminal repeats of myc-associated proviruses appear structurally intact but are functionally impaired in tumors induced by avian leukosis viruses. | b-cell lymphomas induced in chickens infected with avian leukosis viruses are characterized by integration of the virus within the cellular myc locus and alteration of c-myc expression. although avian leukosis viruses are intact, replication-competent retroviruses, the structures of many myc-associated proviruses are altered by deletions, raising the possibility that proviral defectiveness plays an essential role in oncogenesis. we found that all myc-associated proviruses in 21 independent tumor ... | 1987 | 3037111 |
| targeting of chemical mutagens to differentiating b-lymphocytes in vivo: detection by direct dna labeling and sister chromatid exchange induction. | in vivo systems for analyzing mutagen interactions with a specific differentiating cell population are rare. taking advantage of the unique anatomical features of the bursa of fabricius in the chicken, we explored the possibility of targeting chemical mutagens to a defined differentiating cell population in the animal, namely, the b-lymphocytes series. such cells are known to be the targets for the oncogene-activating avian leukosis virus. targeting of chemicals to cells of the bursa was demonst ... | 1987 | 3492371 |
| unique sequence, ski, in sloan-kettering avian retroviruses with properties of a new cell-derived oncogene. | the sloan-kettering viruses (skvs) are a group of transforming retroviruses that were isolated from chicken embryo cells which had been infected with the avian leukosis virus transformation-defective bratislava 77 (tdb77). each of the skv isolates was shown to contain multiple genomes of different sizes indicating the presence of several viruses in addition to tdb77. to identify and characterize the putative transforming gene(s) of the skvs, we used hybridization selection to isolate the fractio ... | 1986 | 3754014 |
| absence of influence on immune competence by the sex-linked gene (k) determining slow feathering in white leghorn chickens. | males of white leghorn strain crosses heterozygous (kk) for the sex-linked feathering locus genes were mated to rapid-feathering (k-) females to produce rapid- and slow-feathering chicks of both sexes. k did not influence humoral-mediated immunity against challenge with sheep erythrocytes, killed brucella abortus, or killed infectious bursal disease virus. chicks challenged at 3 weeks of age had higher primary responses and higher titers of 2-mercaptoethanol-resistant antibody (igg) than those c ... | 1986 | 3814012 |
| augmented expression of normal c-myc is sufficient for cotransformation of rat embryo cells with a mutant ras gene. | we studied the effect of altered c-myc structure and expression upon the ability of c-myc to promote the transformation of normal rat embryo cells when it was supplemented by ejras (the mutant c-h-ras1 gene from ej/t24 bladder carcinoma cells). we tested several c-myc alleles cloned from normal and tumor tissues of chicken and human origin and found that only ll4myc (derived from a bursal lymphoma in which an avian leukosis virus long terminal repeat resides within the first c-myc intron in the ... | 1985 | 3837844 |
| transcription of three c-myc exons is enhanced in chicken bursal lymphoma cell lines. | the chicken c-myc gene, as defined by its homology to the v-myc gene of mc29 virus, is comprised of two exons. using the techniques of runoff transcription, primer extension, and s1 nuclease protection, we demonstrate that there is a third c-myc exon of approximately equal to 345 base pairs (bp) located 0.7 kbp upstream of the 5' end of the v-myc homology. this first exon is transcribed and present in myc mrna in normal chicken cells. we also examined rna from five cell lines derived from avian ... | 1985 | 3855549 |
| field trials to test the efficacy of polyvalent marek's disease vaccines in layer and broiler breeder chickens. | as a follow-up to earlier trials to evaluate the efficacy of polyvalent marek's disease (md) vaccines in broilers, four trials were conducted with layer or broiler breeder flocks. chickens caccinated with trivalent (md11/75c plus sb-1 plus hvt) and bivalent (sb-1 plus hvt) vaccines were compared with those vaccinated with turkey herpesvirus (hvt) alone. data from three of the four trials indicated polyvalent vaccines were more efficacious than hvt. however, critical interpretations were confound ... | 1985 | 3912753 |
| reaction of chick embryo cells infected with leukosis strain mc29 virus with fluorescein-labeled antibody. | immune serum was prepared in the rabbit with bai strain a leukosis virus isolated by centrifugal fractionation from the plasma of chickens with myeloblastic leukemia and further purified on a potassium tartrate gradient. antibody to group-specific antigen was demonstrated in the serum by immunoelectrophoresis and immunodiffusion. fluorescein-conjugated serum was used unabsorbed and absorbed with chick cells for study of acetone-fixed chick embryo cells uninfected or infected with strain mc29 avi ... | 1969 | 4186277 |
| sites of avian leukosis virus multiplication in congenitally infected chickens. | 1967 | 4289506 | |
| multiplication of avian leukosis virus in endocrine organs of congenitally infected chickens. | 1969 | 4303829 | |
| induction of transplantation resistance to rous sarcoma isograft by avian leukosis virus. | 1969 | 4311545 | |
| the n-terminal amino acid sequence of two avian leukosis group specific antigens. | two group-specific antigenic proteins from an avian leukosis virus have been compared by amino acid analysis, tryptic peptide fingerprinting, and n-terminal sequence determination, and found to be dissimilar. there was microheterogeneity in the structure of the protein gs-b at residues 6; threonine and glutamic acid were found. | 1970 | 4321347 |
| detection of avian leukosis viruses in chickens by an in vivo rous sarcoma virus genome rescue test. | 1971 | 4325822 | |
| the presence of avian leukosis virus group-specific antibodies in chicken sera. | 1971 | 4329589 | |
| widespread presence, in chickens, of dna complementary to the rna genome of avian leukosis viruses. | dna-rna hybridization experiments have demonstrated the widespread presence in chickens of dna complementary to the rna of avian myeloblastosis virus. all apparently normal chicken embryos, or adult chickens that were tested, contained viral dna in amounts ranging from 1.7 to 4.6 viral genome equivalents per cell. embryos that were negative or positive for the group-specific antigen of avian leukosis viruses contained the same amount of viral dna. embryos from a strain of chickens free of leukos ... | 1972 | 4335067 |
| detection and assay of avian tumor virus group-specific antigen and antibody by the paired radioiodine-labeled antibody technique. | the paired radioiodine-labeled antibody technique (prilat) was applied to the detection and quantitation of avian tumor virus group-specific (gs) antigens and antibody. the technique proved to be specific, repeatable, and appreciably more sensitive than the microcomplement-fixation test for avian leukosis (cofal). the prilat facilitated direct measurement of comparative antigen content of several types of transformed, neoplastic, or virus-infected cells and the magnitude of nonspecific antibody ... | 1972 | 4335519 |
| cell cycle-dependent activation of rous sarcoma virus-infected stationary chicken cells: avian leukosis virus group-specific antigens and ribonucleic acid. | stationary chicken embryo fibroblasts exposed to rous sarcoma virus (rsv) remained stably infected for at least 5 days, but they did not release infectious virus or become transformed until after cell division. these infected stationary cells did not contain avian leukosis virus group-specific antigens or ribonucleic acid (rna) hybridizable to deoxyribonucleic acid (dna) made by the rsv endogenous rna-directed dna polymerase activity. | 1972 | 4339198 |
| pathogenicity of some clones from field isolates of avian leukosis viruses. | 1972 | 4344740 | |
| isolation of defective mutant of avian sarcoma virus. | a colony of transformed cells was isolated from chick-embryo cells infected with a stock of nondefective schmidt-ruppin strain of rous sarcoma virus. the virus recovered from this colony was a stable defective mutant very similar to the bryan strain of rous sarcoma virus in the following characteristics: (i) noninfectiousness of virus particles released from transformed cells that lack helper factor; (ii) formation of infectious pseudotypes by coinfection with avian leukosis virus or by interact ... | 1973 | 4357873 |
| presence of avian leukosis virus genes, in dna form in normal chickens. | 1973 | 4360180 | |
| antibodies in chickens against avian leukosis virus group specific antigen. | 1973 | 4360193 | |
| biological and biochemical evidence for an interaction between marek's disease herpesvirus and avian leukosis virus in vivo. | the dna-containing epstein-barr herpesvirus has been implicated in the etiology of burkitt's lymphoma, a malignant tumor of children in africa. recently, however, particles possessing four biochemical characteristics of rna tumor viruses have also been identified in these tumors. the fact that both types of viruses are found suggests that an interaction between them may be playing a role in the etiology of burkitt's lymphoma. to explore this possibility with a defined animal model, experiments w ... | 1973 | 4361680 |
| isolation of a transplantable cell line induced by the mc29 avian leukosis virus. | 1974 | 4363662 | |
| responses of isolator-derived and conventional chickens to marek's disease herpesvirus and avian leukosis virus. | 1974 | 4364733 | |
| avian tumor virus rna: a comparison of three sarcoma viruses and their transformation-defective derivatives by oligonucleotide fingerprinting and dna-rna hybridization. | earlier electrophoretic analyses have shown that the 60-70s rna of avian sarcoma viruses contains a characteristic subunit, termed class a subunit, which has a lower electrophoretic mobility than class b subunit found in transformation-defective derivatives of sarcoma viruses and in avian leukosis viruses. we have compared the rnas of three nondefective avian sarcoma viruses, b77 and prague and schmidt-ruppin strains of rous sarcoma virus, with those of their transformation-defective (td) deriva ... | 1973 | 4365699 |
| evidence for the vertical transmission of 'non-infectious' avian leukosis virus in 'leukosis-free' chickens. | 1970 | 4376360 | |
| virus particles and viral antigens in chicken tissues free of infectious avian leukosis virus. | 1967 | 5233847 | |
| nucleotide sequence 5' of the chicken c-myc coding region: localization of a noncoding exon that is absent from myc transcripts in most avian leukosis virus-induced lymphomas. | we have determined the nucleotide sequence of the 2.2-kilobase-pair region upstream of the chicken c-myc coding exons. using rna blot analysis, we have localized a noncoding exon to a region that is separated from the c-myc coding sequences by an intron of 700-800 base pairs. in most avian leukosis virus-induced lymphomas proviral integration has occurred within, or downstream of, the first exon, thus presumably displacing the regulatory sequences that normally control c-myc expression. more tha ... | 1984 | 6087343 |
| metabolism and expression of rna polymerase ii transcripts in influenza virus-infected cells. | influenza virus infection has adverse effects on the metabolism of two representative rna polymerase ii transcripts in chicken embryo fibroblasts, those coding for beta-actin and for avian leukosis virus (alv) proteins. proviral alv dna was integrated into host cell dna by prior infection with alv. within 1 h after influenza virus infection, the rate of transcription of beta-actin and alv sequences decreased 40 to 60%, as determined by labeling the cells for 5 min with [3h]uridine and by in vitr ... | 1984 | 6095046 |
| influence of endogenous viral (ev) gene expression and strain of exogenous avian leukosis virus (alv) on mortality and alv infection and shedding in chickens. | two experiments were conducted to determine the influence of endogenous viral (ev) gene expression on the response of chicken to day-old inoculation with two laboratory and two field strains of avian leukosis virus (alv). the ev2- and ev3-negative semi-congenic chickens had much higher mortality from a unique non-neoplastic syndrome (nns) than ev2- and ev3-positive semi-congenic chickens after inoculation with alv strain rav-1. the three other alv strains induced little nns. all four strains of ... | 1984 | 6098248 |
| radioimmunological comparison of the dna polymerases of avian retroviruses. | 125i-labeled dna polymerases of avian myeloblastosis virus and spleen necrosis virus were used in a radioimmunological characterization of avian retrovirus dna polymerases. it was shown that avian leukosis virus and reticuloendotheliosis virus dna polymerases do not cross-react in radioimmunoassays. within the avian leukosis virus species, species-specific and type-specific antigenic determinants of the dna polymerase were defined. the previous finding of genus-specific antigenic determinants in ... | 1980 | 6154153 |
| specific antigenic relationships between the rna-dependent dna polymerases of avian reticuloendotheliosis viruses and mammalian type c retroviruses. | immunoglobulin g directed against the dna polymerase of rauscher murine leukemia virus (r-mulv) could bind to 125i-labeled dna polymerase of spleen necrosis virus (snv), a member of the reticuloendotheliosis virus (rev) species. competition radioimmunoassays showed the specificity of this cross-reaction. the antigenic determinants common to snv and r-mulv dna polymerases were shared completely by the dna polymerases of gross mulv, moloney mulv, rd 114 virus, rev-t, and duck infectious anemia vir ... | 1980 | 6154804 |
| generation of transforming viruses in cultures of chicken fibroblasts infected with an avian leukosis virus. | during serial passages of an avian leukosis virus (the transformation-defective, src deletion mutant of bratislava 77 avian sarcoma virus, designated tdb77) in chicken embryo fibroblasts, viruses which transformed chicken embryo fibroblasts in vitro emerged. chicken embryo fibroblasts infected with these viruses (sk770 and sk780) had a distinctive morphology, formed foci in monolayer cultures, and grew independent of anchorage in semisolid agar. bone marrow cells were not transformed by these vi ... | 1981 | 6169846 |
| stability of avian leukosis virus type-specific antigen in the cell after fixation in periodate-lysine-paraformaldehyde. | stability of avian leukosis virus type-specific antigen in chicken embryo fibroblasts after fixation in periodate-lysine-paraformaldehyde was tested by the indirect immunoperoxidase method. antigen that had been steeped in 0.015m tris-hcl saline buffer solution containing 20% bovine serum and 30% glycerin was preserved at -20 degrees c, 4 degrees c and room temperature without loss of its antigenicity as long as 16 weeks. it was also stable against heat treatment at 56 degrees c, acid treatment ... | 1982 | 6176884 |
| monoclonal antibodies with specificity for three different serotypes of marek's disease viruses in chickens. | a total of 50 antibody-secreting hybridoma cells against marek's disease virus (mdv) and turkey herpesvirus (hvt) have been produced. eleven hybridomas were used for serotyping a panel of 15 pathogenic and nonpathogenic strains of mdv and hvt, representing three serotypes. the antibodies from the culture medium have fluorescence antibody (fa) titers of up to 100 and those from mouse ascitic fluid have titers ranging from 10(4) to 10(6). monoclonal antibody t81 is type-common, i.e., it reacts at ... | 1983 | 6184394 |
| immunohistochemical identification of group specific antigen in avian leukosis virus infected chickens. | an indirect immunoperoxidase method was employed in the detection of the group specific antigen of avian leukosis virus in the oviduct, spleen, myocardium and bursae of fabricius of chickens. in the magnum of the oviduct the group specific antigen was detected at the base and in the lumina of glands. in the spleen the group specific antigen was found in and around the arterioles, sheathed capillaries, and in the capsular tissue. in the myocardium the group specific antigen was present in the int ... | 1984 | 6206933 |
| correlation between cell killing and massive second-round superinfection by members of some subgroups of avian leukosis virus. | avian leukosis viruses of subgroups b, d, and f are cytopathic for chicken cells, whereas viruses of subgroups a, c, and e are not. the amounts of unintegrated linear viral dna in cells at different times after infection with cytopathic or noncytopathic viruses were determined by hybridization and transfection assays. shortly after infection, there is a transient accumulation of unintegrated linear viral dna in cells infected with cytopathic avian leukosis viruses. by 10 days after infection, th ... | 1980 | 6245246 |
| pathogenesis of virus-induced osteopetrosis in the chicken. | infection of chicken embryos with a nondefective avian leukosis virus mav-2(0) induced bone hyperplasia and profound suppression of bursal and thymic lymphoid cell development within 2- to 3 weeks after hatching. a time-course study of infectivity during embryonal life showed a gradual loss of susceptibility between the 10th day of incubation and hatching. this finding suggests that an embryonal stem cell either before or early after seeding into the bone and primary lymphoid organs is a virus-s ... | 1980 | 6248593 |
| subgroup-e avian-leukosis-virus-associated disease in chickens. | 1980 | 6253188 | |
| performance of 3 successive generations of specified-pathogenfree chickens maintained as a closed flock. | no antibodies against salmonella pullorum, mycoplasma gallisepticum, mycoplasma synoviae, haemophilus gallinarum, fowl pox virus, marek's disease virus, herpes virus of turkey, infectious laryngotracheitis virus, avian adenovirus, avian reovirus, infectious bursal disease virus, reticuloendotheliosis virus, avian leukosis virus, avian encephalomyelitis virus and newcastle disease virus were detectable in the sera obtained from these chickens in 3 generations at various ages. antibodies against i ... | 1980 | 6253742 |
| characterization of y73, an avian sarcoma virus: a unique transforming gene and its product, a phosphopolyprotein with protein kinase activity. | the y73 strain of avian sarcoma virus recently isolated in japan is defective in replication and is associated with subgroup a leukosis virus (yav). the virus caused sarcoma but not acute leukosis when inoculated into chickens. studies on the viral rna showed that a 26s rna, etimated to be 4.8 kilobases long, was y73 viral rna carrying a transforming gene. the 26s rna has sequences in common with the rna of an avian leukosis virus but no homology with the src gene sequence of avian sarcoma virus ... | 1980 | 6255480 |
| analysis of avian leukosis virus dna and rna in bursal tumours: viral gene expression is not required for maintenance of the tumor state. | each of twelve tumors induced by either rous-associated virus-1 or -2 (rav-1 or rav-2) contained a predominant population of cells with alv proviruses integrated at common sites, consistent with a clonal origin. seven of nine rav-2-induced bursal tumors contained single proviruses, and all seven solitary proviruses had suffered deletions. the detailed structures of four of these proviruses show that major deletions had occurred near or at the 5' ends, spanning sequences potentially important in ... | 1981 | 6258797 |
| histone h5 in the immature blood cells of chickens with leukosis induced by avian leukosis virus strain e26. | whole histone was isolated from the immature cells of the peripheral blood of white leghorn chickens, line 151, with leukosis experimentally induced by avian leukosis virus, strain e26 (alv-e26). histone h5 was demonstrated in all samples of these cells and was characterized by electrophoresis in polyacrylamide gel, extraction with perchloric acid, amino acid analysis, and immunodiffusion in agarose gel. histone h5 was not detected in the myeloblasts of chickens with myeloblastosis caused by the ... | 1981 | 6264195 |
| analysis of avian leukosis virus infections with an enzyme immunoassay. | an enzyme-linked immunosorbent assay (elisa) for avian leukosis virus group-specific antigen was used to study infections with and shedding of avian leukosis virus in a commercial flock of chickens with a known high incidence of infection. avian leukosis virus group-specific antigen was detected in serum or cloacal washings from 76% of a group of 100 61-week-old hens. with eggs collected during the next 3 weeks, antigen was detected in the albumen of 88% of the eggs from elisa-positive hens and ... | 1981 | 6265361 |
| oncogenicity of three strains of avian leukosis virus in white leghorn chicks of bk line. | 1980 | 6265807 | |
| expression of forssman antigen of avian lymphoblastoid cell lines transformed by marek's disease virus or avian leukosis virus. | the expression of forssman-type heterophile antigen on marek's disease (md) virus (mdv)-transformed cell lines, mdcc-msbi 1, -hp1, -rp1 and -bp1, and avian leukosis virus (alv)-transformed cell lines, lscc-1104b1 and -1104x5 was investigated by membrane immunofluorescence and complement-dependent antibody cytotoxicity tests. forssman antigen was detected on a high percentage of the cells in two alv-transformed cell lines and on a smaller percentage of splenic lymphocytes from normal chicken. of ... | 1981 | 6267170 |
| cell killing by avian leukosis viruses. | infection of chicken cells with a cytopathic avian leukosis virus resulted in the detachment of killed cells from the culture dish. the detached, dead cells contained more unintegrated viral dna than the attached cells. these results confirm the hypothesis that cell killing after infection with a cytopathic avian leukosis virus is associated with accumulation of large amounts of unintegrated viral dna. no accumulation of large amounts of integrated viral dna was found in cells infected with cyto ... | 1981 | 6270346 |
| host susceptibility to endogenous viruses: defective, glycoprotein-expressing proviruses interfere with infections. | three defective endogenous avian leukosis viruses, ev3, ev6 and ev9, interfered with subgroup e virus infections, ev3, ev6, and ev9 expressed high levels of subgroup e envelope glycoproteins. these glycoproteins reduced the activity of cellular receptors for subgroup e viruses. ev3 and ev6 protected chickens and cultured cells from subgroup e virus infections. | 1981 | 6275116 |
| establishment of b-lymphoblastoid cell lines from marek's disease virus-induced tumors in turkeys. | four lymphoblastoid cell lines were established from tumours of turkeys inoculated with high doses of the ga strain of marek's disease virus (mdv). unlike other md lymphoblastoid cell lines of chicken origin, these mdv transformed turkey line appear to be b lymphocytes and produce immunoglobulin. growth characteristics of these cell lines are slightly different; however, they all produce low levels of mdv-specific antigen and carry the complete genome of the virus as determined by virus rescue i ... | 1982 | 6277804 |
| an igm-producing b lymphoblastoid cell line established from lymphomas induced by a non-defective reticuloendotheliosis virus. | chick syncytial virus (csv), a strain of avian reticuloendotheliosis virus (rev) causes lymphoid tumours in chickens after a prolonged incubation period. a number of csv-induced tumours were examined for cell surface antigen and were found to be of the b cell type and to produce immunoglobulin. attempts were made to grow in vitro cell lines from csv-induced tumours and a lymphoblastoid cell line was established from a liver tumour of a chicken that was inoculated with csv via the yolk sac in emb ... | 1982 | 6278061 |
| effect of endogenous leukosis virus genes on response to infection with avian leukosis and reticuloendotheliosis viruses. | we examined the effect of the presence or absence of endogenous viral gene (ev) 3, which controls expression of group-specific viral and envelope antigens (gs+chf+ phenotype), and ev2, which controls the production of a complete subgroup e virus (v-e+ phenotype), on the response of chickens to rav-1, an exogenous avian leukosis virus (alv) with an antigenic relationship to endogenous virus. after inoculation at one day of age, the chickens lacking either ev gene expression had a lower frequency ... | 1982 | 6285878 |
| sequence of the long terminal repeat and adjacent segments of the endogenous avian virus rous-associated virus 0. | rous-associated virus 0 (rav-0), an endogenous chicken virus, does not cause disease when inoculated into susceptible domestic chickens. an infectious unintegrated circular rav-0 dna was molecularly cloned, and the sequence of the long terminal repeat (ltr) and adjacent segments was determined. the sequence of the ltr was found to be very similar to that of replication-defective endogenous virus ev-1. like the ev-1 ltr, the rav-0 ltr is smaller (278 base pairs instead of 330) than the ltrs of th ... | 1982 | 6286997 |
| studies of avian leukosis virus infection in chickens from a commercial breeder flock. | progeny chicks from a commercial breeder flock with a high rate of avian leukosis virus (alv) infection were classified as congenitally or contact infected with alv on the basis of virus tests on their meconia at hatching and the presence or absence of antibodies at 20 weeks of age. the alv infection profile, shedding, tumor mortality, and egg production in the congenitally-infected chickens were compared with those in the contact-infected hatchmates. results show that viremic-tolerant hens clas ... | 1982 | 6287446 |
| common proviral integration sites in c57bl mouse lymphomas induced by radiation leukemia virus and absence of novel virus-related sequences in radiogenic lymphoma dna. | three c57bl/ka mice were inoculated with radlv/vl3, a thymotropic and leukemogenic virus population released by the permanent bl/vl3 cell line, which was derived from a c57bl/ka lymphoma induced by radiation leukemia virus (radlv). the neoplastic thymus and bone marrow cells from these mice were grown until the cultures became permanently established, and their dnas were examined for the presence of virus-related sequences by restriction enzyme analysis. all six cell lines displayed identical ec ... | 1982 | 6289014 |
| isolation of 16l virus: a rapidly transforming sarcoma virus from an avian leukosis virus-induced sarcoma. | we have isolated a replication-defective rapidly transforming sarcoma virus (designated 16l virus) from a fibro-sarcoma in a chicken infected with td107a, a transformation-defective deletion mutant of subgroup a schmidt-ruppin rous sarcoma virus. 16l virus transforms fibroblasts and causes sarcomas in infected chickens within 2 wk. its genomic rna is 6.0 kilobases and contains sequences homologous to the transforming gene (fps) of fujinami sarcoma virus (fsv). rnase t1 oligonucleotide analysis s ... | 1982 | 6289331 |
| characterization of c-lil, a chicken cellular sequence associated with a stock of b77 avian sarcoma virus. | using biochemical methods, we have shown that a new specific sequence, v-lil, is associated with a given stock of b77 avian sarcoma virus (clone 9). we prepared a dna complementary to v-lil sequences, using substractive hybridizations, and investigated the properties of this sequence. v-lil has a genetic complexity of ca. 2,000 nucleotides and is not present in various stocks of avian sarcoma virus, avian leukosis virus, or defective leukemia virus. v-lil is not associated with b77 avian sarcoma ... | 1982 | 6292471 |
| orientation and position of avian leukosis virus dna relative to the cellular oncogene c-myc in b-lymphoma tumors of highly susceptible 15i5 x 7(2) chickens. | we previously reported our characterizations of the b-lymphoma tumors induced in a highly susceptible line of chickens (15i5 x 7(2)) by the avian leukosis virus rav-1 (proc. natl. acad. sci. 78:3418-3422, 1981). we demonstrated that in greater than 90% of the tumors, the rav-1 provirus is integrated near a cellular oncogene, c-myc. in the present study, we devised a simple approach, relying on sali digestion, for further defining the locations and orientations of the proviruses with respect to t ... | 1982 | 6292531 |
| effect of intron size on splicing efficiency in retroviral transcripts. | to study the effect of intron size on splicing efficiency we have varied the size of the avian leukosis virus (alv) env mrna intron in a cloned alv genome. this was accomplished by deletion of alv sequences or insertion of phage lambda dna. the effect of these modifications on splicing was analyzed by microinjection of the modified clones into rsv(-) chicken cells. viral env mrna when transcribed and properly spliced within these cells complemented the rsv(-) env deficiency leading to the produc ... | 1982 | 6292870 |
| pathogenicity of avian leukosis viruses. | three methods were used in attempts to obtain non-oncogenic avian leukosis virus for possible use as an immunoprophylactic agent for the control of lymphoid leukosis in chickens. these were: 1) isolate a nononcogenic virus from commercial breeder flocks experiencing very little or no lymphoid leukosis; 2) obtain a non-oncogenic recombinant from mixed infection of a strain with low oncogenicity, rous-associated virus-60 (rav-60), with rav-1 or rav-2 in cell culture; and 3) attempt to attenuate su ... | 1982 | 6293446 |
| the effectiveness of selection for reduced avian leukosis virus shedding in different chicken strains. | 1982 | 6293449 | |
| comparison of the oligosaccharide moieties of the major envelope glycoproteins of the subgroup a and subgroup b avian myeloblastosis-associated viruses. | the nature of the oligosaccharide chains of the major envelope glycoprotein, gp85, from avian myeloblastosis-associated viruses has been examined for the subgroup a and subgroup b viruses replicated in fibroblasts from the same chicken embryos. pronase-digested glycopeptides from [3h]mannose- or [3h]glucosamine-labeled viruses were analyzed by the combined techniques of gel filtration, endo-beta-n-acetylglucosaminidase digestion, and concanavalin a affinity chromatography. the gp85 protein from ... | 1983 | 6296432 |
| identification and nucleotide sequence of a human locus homologous to the v-myc oncogene of avian myelocytomatosis virus mc29. | avian myelocytomatosis virus mc29 is a replication-defective acute leukaemia virus which induces a variety of tumours in chickens including sarcomas, renal and hepatic carcinomas, and myelocytomatosis. the oncogenic potential of the virus is mediated by the gene v-myc, acquired from sequences (c-myc) present in normal uninfected chicken dna. sequences closely related to chicken c-myc have been highly conserved throughout evolution, from drosophila to vertebrates. the hypothesis that c-myc may be ... | 1983 | 6298632 |
| induction of angiosarcomas by ring-necked pheasant virus. | ring-necked pheasant virus, an avian leukosis virus, when injected into 10-day old chick embryos, caused angiosarcomas in the lungs of infected chickens within a short time. angiosarcomas appeared as localized foci of proliferating cells in the lungs as early as 2 weeks posthatch, and by 6 weeks, the lungs of the infected chickens were frequently filled with tumor cells. between 3 and 10 weeks of age, 80% of infected chickens died of the angiosarcomas; the 20% which lived 8 weeks or longer had s ... | 1983 | 6299960 |
| rapid induction of hypothyroidism by an avian leukosis virus. | infection of 10-day chicken embryos with an avian leukosis virus, rav-7, resulted in hypothyroidism within 3 weeks posthatching. histological examination of the thyroids from infected chickens showed an extensive infiltration of lymphoblastoid cells by 7 days posthatching. areas resembling germinal centers were present in the thyroids of infected chickens by 3 weeks posthatching. examination of circulating thyroid and pancreas hormones showed a significant reduction in t3 and t4 levels and a tre ... | 1983 | 6302005 |
| studies of reticuloendotheliosis virus-induced lymphomagenesis in chickens. | seventy-three percent of chickens inoculated with the chick syncytial strain of reticuloendotheliosis virus (rev) at hatching developed lymphomas by 39 weeks of age. neonatal treatment with cyclophosphamide or surgical bursectomy at 2, 4, 8, or 12 weeks of age significantly (p less than 0.01) reduced lymphoma development. in a further experiment, surgical bursectomy of rev-infected chickens followed by intravenous inoculation of the chickens with a single cell suspension of their own bursa cells ... | 1983 | 6303293 |
| activation of the cellular oncogene c-erbb by ltr insertion: molecular basis for induction of erythroblastosis by avian leukosis virus. | avian leukosis virus (alv), a slowly oncogenic retrovirus, induces in chickens a variety of neoplasms, including lymphoid leukosis and erythroblastosis. in lymphoid leukosis, a cellular oncogene, c-myc, is activated by the insertion of alv ltr. we provide evidence that alv utilizes a similar mechanism in erythroblastosis induction by activating a different cellular oncogene, c-erbb. we report the isolation, from leukemic erythroblast dna, of a clone that represents the viral-cell junction fragme ... | 1983 | 6305505 |
| b5 and b15 associated with progressive marek's disease, rous sarcoma, and avian leukosis virus-induced tumors in inbred 15i4 chickens. | rprl 15i4 inbred chickens are nearly histocompatible except for the b5 and b15 haplotypes that determine the major transplantation antigens. b5b5 and b15b15 15i4 chickens were equally and highly susceptible to tumors induced by marek's disease, rous sarcoma, or avian leukosis viruses (alv), suggesting both of these haplotypes may determine a general influence leading to tumor development. the 15i4 birds were highly susceptible to erythroblastosis, and most developed immunological tolerance to th ... | 1983 | 6306630 |
| viral sequences determining the oncogenicity of avian leukosis viruses. | our analyses of the sequence of the recombinant virus ntre7 and comparison with its endogenous and exogenous alv parents indicate that a section of approximately 400 base pairs at the 3' end of the genome encodes a function which is required for oncogenicity. this section includes an exogenous virus specific region (xsr) of approximately 148 base pairs and the u3 region of the ltr. at present it seems most likely that the function required for oncogenicity is the transcription promoter contained ... | 1983 | 6306683 |
| cancer induction by insertional mutagenesis: the role of viral genes in avian leukosis virus induced cancers. | 1983 | 6306689 | |
| immunological phenotype of lymphomas induced by avian leukosis viruses. | the production of immunoglobulin by six cell lines derived from bursal tumors induced by avian leukosis virus follows two general patterns: (i) three cell lines that have been extensively passaged in culture synthesize and secrete light chains only; (ii) three cell lines that are recently isolated produce and secrete monomeric immunoglobulin m in addition to free light chains. all six cell lines synthesize and secrete both glycosylated and unglycosylated forms of light chain. we conclude that th ... | 1983 | 6308424 |
| avian leukosis virus infection and congenital transmission in lines of chickens resisting selection for reduced shedding. | two lines (d and e) of three breeder lines of chickens that had resisted selection for reduced avian leukosis virus (alv) congenital transmission on the breeder's premises did not resist the same selection procedures (tests for gs-antigen in albumen) under laboratory conditions. the incidence of alv congenital transmission in the remaining third line (f) was spontaneously reduced from 13% to 0.9%. environmental alv exposure of uninfected chicks after hatching induced 7-10% of the progeny from li ... | 1983 | 6314970 |
| evidence that avian tumour virus-immune chicken sera recognize only viral structural antigens on the surface of avian tumour virus-infected cells. | the specificity of the humoral response of chickens to avian tumour viruses (atv) was investigated by reacting atv-immune sera with triton x-100 extracts of uninfected, infected and transformed chicken embryo fibroblasts. analysis of these immune reactions by polyacrylamide gel electrophoresis revealed that avian leukosis virus-challenged and rous sarcoma virus-challenged chickens recognized only two major cell surface antigens of 100000 and 29000 mol. wt. which were present on transformed and n ... | 1983 | 6315863 |