TitleAbstractYear(sorted ascending)
effect of avian myeloblastosis virus in the japanese quail.moscovici, carlo (university of colorado medical center, denver), and e. h. macintyre. effect of avian myeloblastosis virus in the japanese quail. j. bacteriol. 92:1141-1149. 1966.-avian myeloblastosis virus (amv) induced a spectrum of neoplasms in japanese quail (coturnix coturnix japonica) which was similar to that observed in the chicken, with one exception: the total absence of acute myeloblastic leukemia in quail. studies in vivo as well as in vitro suggested that the cause for this differe ...19664288797
[synthesis of uridilic nucleotides and tmp in bone marrow of chickens infected with avian myeloblastosis virus]. 19684298767
effects of genetic cellular resistance on cell transformation and virus replication in chicken hematopoietic cell cultures infected with avian myeloblastosis virus (bai-a). 19684300361
studies on the rna from avian myeloblastosis virus. 19694302800
the oncogenic effects of nontransforming viruses from avian myeloblastosis virus. 19694308011
dna complementary to viral rna in leukemic cells induced by avian myeloblastosis virus.nucleic acid hybridization studies were made between 71s-amv-rna and dna from leukemic myeloblasts and from normal chicken cells. there was homology between the viral rna and chicken cell dna and to a greater extent between viral rna and leukemic cell dna. leukemic cell dna hybridized approximately twice as much viral rna as did normal chicken dna. thermal melting studies showed that the viral rna bound to normal and leukemic cell dna consists of long polynucleotides (t(m) = 87 degrees and 92 de ...19704317913
mitochondrial dna from cells transformed by avian myeloblastosis virus. 19714324717
[avian myeloblastosis virus. model for study of leukemia due to virus]. 19714335902
endogenous rna-directed dna polymerase activity in uninfected chicken embryos.early chicken embryos that are either positive or negative for group-specific antigens of avian leukosis viruses contained endogenous rna-directed dna polymerase activity. this endogenous dna polymerase activity was not increased after mixture of soluble dna polymerases isolated from chicken embryos with disrupted chicken embryo cells. the endogenous activity was resistant to treatment with deoxyribonuclease, and the initial rate of dna synthesis was partially resistant to actinomycin d. in cont ...19724338597
[detection of avian myeloblastosis virus in chicken fibroblast cultures treated with dna from virus-producing leukemic cells]. 19724339978
structural studies on avian myeloblastosis virus: rapid purification and quantitation. 19724343190
distribution of deoxyribonucleic acid complementary to the ribonucleic acid of avian myeloblastosis virus in tissues of normal and tumor-bearing chickens.(3)h-labeled 70s ribonucleic acid (rna) from purified avian myeloblastosis virus (amv) was used as a probe in deoxyribonucleic acid (dna)-rna hybridization experiments to detect the presence of dna complementary to the amv genome in various tissues from noninfected normal chickens and from chickens infected with amv. there was a remarkable constancy in the average cellular concentration of virus-specific dna found in every tissue from the same uninfected chicken, and even in different chickens f ...19724344249
terminal nucleotides of avian myeloblastosis virus rna and of ribosomal rna from chicken leukemic myeloblasts. 19724347181
early stimulation of dna synthesis in chicken fibroblasts infected by avian myeloblastosis virus. 19724333571
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 ...19724335067
serological analysis of the deoxyribonucleic acid polymerase of avian oncornaviruses. ii. comparison of avian deoxyribonucleic acid polymerases.monospecific antiserum prepared against the isolated deoxyribonucleic acid (dna) polymerase of avian myeloblastosis virus (amv) neutralized the endogenous ribonucleic acid-instructed dna polymerase activity of detergent-disrupted virus. the viral polymerase was serologically unrelated to the seven major structural polypeptides of amv. furthermore, the viral enzyme was distinguished from normal cellular dna polymerases by serological criteria; thus, antiserum against the viral enzyme neutralized ...19724117966
outer membrane of avian myeloblastosis virus.guinea pigs immunized intracerebrally with avian myeloblastosis virus (amv) produced antiserum which reacted with intact virus particles in complement fixation. the antigen in question appeared to be located on the surface of the virion and could be distinguished from the type-specific virus envelope and the group-specific internal antigens of chicken leukosis-sarcoma viruses (chilsv). the material could be isolated by sequential treatments of amv with bromelin, tween 20, and freeze-thawing, and ...19734128385
aminoacyl-trna synthetase activity in virions of avian myeloblastosis virus. 19734350587
quantitative determination and location of newly synthesized virus-specific ribonucleic acid in chicken cells infected with rous sarcoma virus.a sensitive and quantitative nucleic acid hybridization assay for the detection of radioactively labeled avian tumor virus-specific rna in infected chicken cells has been developed. in our experiments we made use of the fact that dna synthesized by virions of avian myeloblastosis virus in the presence of actinomycin d (amv dna) is complementary to at least 35% of the sequences of 70s rna from the schmidt-ruppin strain (srv) of rous sarcoma virus. annealing of radioactive rna (either srv rna or r ...19734350719
spontaneous regression of leukemia in chickens infected with avian myeloblastosis virus. 19734352529
identification of a large polypeptide precursor of avian oncornavirus proteins.antibody to partially disrupted avian myeloblastosis virus was used to selectively precipitate newly synthesized intracellular viral polypeptides from extracts of infected chicken cells. when analyzed by sodium dodecyl sulfate-gel electrophoresis, immune precipitates from extracts of cells pulse-labeled for 10 min with [(35)s]methionine contain none of the major virion polypeptides. instead they show prominent viral specific polypeptides of molecular weight 76,000 and 12,000, as well as minor qu ...19734352653
[resistance of german chicken lines against avian myeloblastosis virus (amv)]. 19734354748
separation of dna sequences complementary to the rna of avian myeloblastosis virus from chicken dna by alkaline cesium chloride density sedimentation.density gradient sedimentation in alkaline cesium chloride of dna from normal chicken embryos or leukemic myeloblasts fragmented to a size of 13s revealed that the dna sequences complementary to 70s avian myeloblastosis virus rna sedimented in the high guanine plus cytosine region ahead of the main peak of cellular dna. when the dna was fragmented into pieces of 6.6s there was a broader distribution of the dna sequences complementary to the viral rna. this technique could be employed as a step t ...19734355853
chromatographic analyses of isoaccepting trnas from avian myeloblastosis virus.avian myeloblastosis virus (amv) 4s rna was tested for amino acid acceptor activity for 18 of the 20 amino acids. a nonrandom distribution of viral trnas was found compared with trna from normal liver or from amv-infected leukemic myeloblasts, confirming previous reports. methionine and proline trnas were considerably enriched, whereas glutamic acid, glutamine, serine, tyrosine, and valine trnas were markedly depleted in amv relative to homologous cellular trnas. the seven amv trnas with the gre ...19734355849
integrated state of oncornavirus dna in normal chicken cells and in cells transformed by avian myeloblastosis virus.the covalent linkage of oncornavirus-specific dna to chicken dna was investigated in normal chicken embryo fibroblasts (cef) and in virus-producing leukemic cells transformed by avian myeloblastosis virus (amv). the virus-specific sequences present in cellular dna fractionated by different methods were detected by dna-rna hybridization by using 70s amv rna as a probe. in cef and in leukemic cells, the viral dna appeared to be present only in the nucleus. after cesium chloride-ethidium bromide de ...19734359950
lack of serological relationship among dna polymerases of avian leukosis-sarcoma viruses, reticuloendotheliosis viruses, and chicken cells.antibodies against a large and a small dna polymerase isolated from chicken embryos and against avian myeloblastosis virus dna polymerase were used to study the serological relationships of the dna polymerase activities of three avian systems with rna and a dna polymerase-avian leukosis-sarcoma viruses, reticuloendotheliosis viruses, and a fraction from uninfected chicken cells. the dna polymerase activity of disrupted virions of all avian leukosis-sarcoma viruses tested was neutralized to the s ...19734127028
rna-dependent dna polymerase (reverse transcriptase) from avian myeloblastosis virus: a zinc metalloenzyme.rna tumor viruses contain a characteristic rna-dependent dna polymerase (reverse transcriptase) which has been thought to be related to the induction of leukemia by this virus. a disturbance in a zinc-dependent enzyme system was first postulated to account for the demonstrated differences in zinc metabolism of normal and leukemic leukocytes [vallee et al. in (1949) acta unio. int. contra cancrum 6, 869 and (1950) acta unio. int. contra cancrum 6, 1102]. in order to investigate the relationship b ...19744134617
presence in leukemic cells of avian myeloblastosis virus-specific dna sequences absent in normal chicken cells.(3)h-labeled 35s rna from purified avian myeloblastosis virus (amv) was exhaustively hybridized with an excess of normal chicken dna to remove all viral rna sequences which are complementary to dna from uninfected cells. the [(3)h]rna which failed to hybridize was isolated by hydroxylapatite column chromatography which separates dna-rna hybrids from single-stranded [(3)h]rna. the residual rna hybridized to leukemic chicken dna but did not rehybridize with normal chicken dna. this demonstrates co ...19744365719
virus release by cell colonies derived from chickens and cultures infected with avian myeloblastosis virus. 19744366504
transfection of chicken embryo cells with dna extracted from avian virus-producing neoplastic cells.dna isolated from avian virus-producing leukemic myeloblasts induced the production of viruses, but not morphological transformation, in cultivated chicken fibroblasts. the recovered virus had the same biological characteristics as the original avian myeloblastosis virus (amv) and produced myeloblastosis and nephroblastomas when injected into chickens. neutralization experiments with chicken anti-amv-bai strain a sera showed an antigenic community between the dna-transfected virus and the origin ...19744369392
differences between the integration of avian myeloblastosis virus dna in leukemic cells and of endogenous viral dna in normal chicken cells.the nature of integrated viral dna in normal and leukemic chicken cells has been studied by sequential nucleic acid hybridization procedures that localize the viral specific dna in cellular dna regions differing in reiteration frequency. first, dna.dna reassociation was employed to fractionate cellular dna sequences according to their reiteration frequencies. next, the dna in each fraction was denatured, immobilized on nitrocellulose filters, and then hybridized with viral [(3)h]rna. in normal c ...19744369920
protein synthesizing activities of ribosome-like structure isolated from avian myeloblastosis virus in chicken cell-free protein synthesis. 19744372573
isolation of avian nephroblastoma virus from avian myeloblastosis virus by the infectious dna technique. 19744375132
reliability of the rna-dna filter hybridization for the detection of oncornavirus-specific dna sequences.denatured dna from leukemic myeloblasts or uninfected chicken embryos, immobilized on nitrocellulose filters, was hybridized to a vast excess of [(3)h]70s rna from purified avian myeloblastosis virus. the viral rna was eluted from the rna-dna hybrids, purified, and then rehybridized in solution to an excess of either leukemic or normal chicken embryonic dna. this study revealed that all the slow and the fast hybridizing viral rna sequences detectable by liquid hybridization in dna excess had hyb ...19744367899
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 ...197416789139
ribonucleotide sequence homology among avian oncornaviruses.rna sequence relatedness among avian rna tumor virus genomes was analyzed by inhibition of dna-rna hybrid formation between 3h-labeled 35s viral rna and an excess of leukemic or normal chicken cell dna with increasing concentrations of unlabeled 35s viral rna. the avian viruses tested were rous associated virus (rav)-3, avian myeloblastosis virus (amv), rav-60, rav-61, and b-77 sarcoma virus. hybridization of 3h-labeled 35s amv rna with dna from normal chicken cells was inhibited by unlabeled 35 ...1975173876
comparison of an avian osteopetrosis virus with an avian lymphomatosis virus by rna-dna hybridization.myeloblastosis-associated virus (mav)-2(0), a virus which was derived from avian myeloblastosis virus and induced a high incidence of osteopetrosis, was compared with avian lymphomatosis virus 5938, a recent field isolate which induced a high incidence of lymphomatosis. the following information was obtained. (i) mav-2(0) induced osteopetrosis, nephroblastoma, and a very low incidence of hepatocellular carcinoma. no difference was seen in the oncogenic spectrum of end point and plaque-purified m ...1975173880
acquisition of viral dna sequences in target organs of chickens infected with avian myeloblastosis virus.the distribution of oncornavirus dna sequences in various tissues of normal chickens and of chickens with leukemia or kidney tumors induced by avian myeloblastosis virus (amv) was analyzed by dna-rna hybridization using 35s amv rna as a probe. all the tissues from normal chickens which were tested contained the same average cellular concentration of endogenous oncornavirus dna. in contrast, different tissues from lekemic chickens and from chickens bearing kidney tumors contained different concen ...1975170415
use of a specific probe for ovalbumin messenger rna to quantitate estrogen-induced gene transcripts.dna complementary to purified ovalbumin messenger rna (cdna ov) was synthesized in vitro using rna-directed dna olymerase from avian myeloblastosis virus. this cdnaov was then employed in hybridization assays to determine the effect of estrogen on the number of ovalbumin mrna (mrnaov) molecules per tubular gland cell of the chick oviduct. the changes in mrnaov were measured in immature chicks during primary stimulation, after hormone withdrawal and again following secondary stimulation of the ch ...197550081
quantitation of rna tumor viruses by spectroscopy of density gradient gels.we have developed a system for virus particle quantitation based on the measurement of the optical absorbance of stained viruses which first have been banded at their buoyant density in an equilibrum 24 to 53% (wt/wt) sucrose density gradient, then fixed in position in the gradient by photopolymerizing an acrylamide-riboflavin mixture in the sucrose, and finally stained and destained. using plasma from mice infected with leukemia virus (rauscher) or chickens infected with avian myeloblastosis vi ...197551099
specific binding of tryptophan transfer rna to avian myeloblastosis virus rna-dependent dna polymerase (reverse transcriptase).the ability of tryptophan trna (trnatrp) to initiate reverse transcription of the 70s rna of avian rna tumor viruses suggested that the reverse transcriptase (rna-dependent dna polymerase; deoxynucleosidetriphosphate: dna deoxynucleotidyltransferase; ec might have a specific binding site for the trna. a complex of trnatrp and the avian myeloblastosis virus reverse transcriptase has been demonstrated using chromatography on sephadex g-100 columns. of all the chicken trnas, only trnatrp a ...197552156
interspersion of sequences in avian myeloblastosis virus rna that rapidly hybridize with leukemic chicken cell dna.liquid hybridization of progressively smaller fragments (35s, 27s, 15.5s, 12.5s, and 8s) of poly(a)-selected avian myeloblastosis virus rna with excess dna from leukemic chicken myeloblasts revealed that all sizes of rna contained sequences complementary to both slowly and rapidly hybridizing cellular dna sequences. apparently, the rna sequences which hybridize rapidly with excesses of cellular dna are not restricted to any one region of the avian myeloblastosis virus 35s rna. instead, they appe ...1975163372
isolation of two subgroup-specific leukemogenic viruses from standard avian myeloblastosis virus.two populations of virus having subgroup-specific homogeneity (a and b) were isolated from standard avian myeloblastosis virus stocks by passage in vivo through genetically defined chickens. each possesses leukemogenic activity in vivo. other properties and potential usefulness of these agents are discussed.1975163925
two levels of genetic resistance to lymphoid leukosis.two levels of genetic resistance to lymphoid leukosis are recognized: 1) cellular resistance to virus infection; and 2) resistance to tumor development in leukosis-virus-infected birds. resistance to infection is simply inherited but is very specific for the subgroup of virus. inheritance of resistance to tumor development is more complex but appears to be less subgroup-specific. a breeder may wish to select for resistance to infection of virus eradication is the goal. if his goal is the reducti ...1975168849
studies on characterization of the integration sites of avian rna tumor virus-specific dna.a sequential hybridization procedure is described which allows the integration sites of viral-specific dna to be characterized according to their reassociation kinetics. in addition, this approach enables us to estimate the size of the integrated viral dna. endogenous virus sequences in normal cells appear to be associated with cell sequences reiterated 1200 times, and each integration unit is approximately equal to one 35s rna subunit. in amv-infected cells, the additional amv-specific dna sequ ...1975169002
quantitative and qualitative differences in dna complementary to avian myeloblastosis virus between normal and leukemic chicken cells.hybridization of avian myeloblastosis virus (amv) rna with dna immobilized on filters or in liquid with a vast dna excess was used to measure the viral specific dna sequences in chicken cells. newly synthesized viral dna (v-dna) appears within an hour after infection of chicken embryo fibroblasts (cef) with avian oncornaviruses. a fraction of newly synthesized v-dna becomes integrated into the cellular genome and the remainder gradually disappears. a covalent linkage between v-dna and cellular d ...1975169823
homology between avian oncornavirus rnas and dna from several avian species.3h-labeled 35s rna from avian myeloblastosis virus (amv), rous associated virus (rav)-0, rav-60, rav-61, rav-2, or b-77(w) was hybridized with an excess of cellular dna from different avian species, i.e., normal or leukemic chickens, normal pheasants, turkeys, japanese quails, or ducks. approximately two to three copies of endogenous viral dna were estimated to be present per diploid of normal chicken cell genome. in leukemic chicken myeloblasts induced by amv, the number of viral sequences appe ...1975172655
trna's associated with the 70s rna of avian myeloblastosis virus.the distribtuion of various amino acid trna's in the 4s rna components of avian myeloblastosis virus (amv) and in 4s rna prepared from chicken cmbryo cells, chicken myeloblasts, and chicken livers was determined. this was done by aminoacylating the 4s rna samples with a mixture of 17 radioactive amino acids and subsequently identifying the trna-accepted amino acids on an amino acid analyzer after deacylation. in embryo cells, myeloblasts, and liver, trna's accepting all 1m amino acids were demon ...1975172660
avian myeloblastosis virus-induced lymphosarcoma producing erythroblastic leucosis in chicks.acute myeloblastosis and several forms of tumor, including one case of lymphosarcoma occurred when avian myeloblastosis virus (bai-a strain) was inoculated into newly hatched chicks (spf). the homogenate of lymphosarcoma inoculated intraperitoneally into other newly hatched chicks induced a high incidence of erythroblastic leucosis. electron microscopy did not reveal the presence of c-type virus particles in the tumor tissue. the relationship between avian myeloblastosis virus, lymphosarcoma and ...1975179285
nonspecific immunosuppression and expression of avian myeloblastosis virus (bai strain a).chickens were treated with cyclophosphamide in order to induce nonspecific immunosuppression. treated and untreated animals were injected with avian myeloblastosis virus (amv) or myeloblasts at the age when a pronounced resistance to the disease is observed. chickens treated with cyclophosphamide and then challenged with amv developed acute myeloblastic leukemia in 70 percent. similarly treated chickens transplanted with fresh amv producing myeloblasts exhibited 30 percent incidence of myeloblas ...1976187971
detection by immunofluorescence of avian myeloblastosis virus reverse transcriptase.peripheral blood cells of avian myeloblastosis virus (amv-(infected chickens were examined at various intervals post infection by immunofluorescence. amv revertase was identified in pro- and myeloblasts; it was localized mainly in the perinuclear zone or throughout the cytoplasm. no revertase was found in erythrocytes or granulocytes. blood cells from uninfected chickens of man contained no revertase.197661720
gene specific priming of complementary dna synthesis.dna, complementary to chicken globin mrna was synthesized using either avian myeloblastosis virus reverse transcriptase, or e. coli dna polymerase i. transcriptase cdna sediments at 9 s on sucrose gradients, and is 620 nucleotides in length, representing a complete copy of globin mrna template. in contrast, polymerase i cdna sediments at 4 s, is 100 to 200 nucleotides in length, and is a copy of a small region at the 3'(poly a) end of globin mrna. similarly, transcriptase cdna and polymerase i c ...197664922
reiteration frequency of the gene for tissue-specific histone h5 in the chicken genome.chicken erythroid cells contain a tissue specific histone known as h5 in addition to the five major histone species found in other organisms. the mrna coding for this histone has been isolated by indirect immunoprecipitation from immature, non-dividing reticulocytes in which this is the only histone synthesised. the mrna has been modified by the enzymatic addition of a 3' polyadenylic acid tract, and transcribed into complementary dna (cdna) using the rna-dependent dna-polymerase from avian myel ...19761250413
evidence for tandem integration of avian myeloblastosis virus dna with endogenous provirus in leukemic chicken cells.the integration site of avian myeloblastosis virus (amv) proviral dna in dna from leukemia chicken myeloblasts has been studied by three sequential nucleic acid hybridizations that can localize the proviral dna according to the repetitiveness of the adjacent cellular dna regions. first, large denatured cellular dna fragments (2.1 x 10(6) daltons) were reassociated and fractionated according to sequence reiteration frequenct. next, dna remaining single-stranded in each fraction was immobilized on ...1976179099
rate of virus-specific rna synthesis in synchronized chicken embryo fibroblasts infected with avian leukosis virus.the rate of avian leukosis virus (alv)-specific rna synthesis has been examined in bot- uninfected and alv-infected synchronized chicken embryo fibroblasts. rna from cells labeled for 2h with [3h]uridine was hybridized with avian myeloblastosis virus poly(dc)-dna, and the hybridized rna was analyzed with poly(i)-spephadex chromatography. approximately 0.5% of the rna synthesized in alv-infected cells was detected as virus specific, and no more than a twofold variation in the rate of synthesis wa ...1976176421
restricted addition of proviral dna in target tissues of chickens infected with avian myeloblastosis virus.proviral dna is synthesized within an hour after infection of chicken cells with an avian oncornavirus and is integrated into nuclear cellular dna within a short time. the viral dna appears to be synthesized as double-stranded molecules of approximately 6 x 10(6) daltons some of which are converted into supercoiled cricles perhaps as a requisite for integration. the endogenous v-dna in normal chicken cells and both the endogenous and amv v-dna in leukemic chicken myeloblasts are covalently linke ...1976188728
effect of estrogen on gene expression in the chick oviduct. effect of estrogen on the sequence and population complexity of chick oviduct poly(a)-containing cellular rna preparations were isolated from chicken oviducts at three different development stages: (a) immature chicks which were chronically stimulated with estrogen; (b) estrogen-stimulated chicks which were then withdrawn from hormone for 12 days; and (c) laying hens. total cellular rna containing 3'-poly(a) sequences (poly(a)-rna) were than isolated from these preparations using oligo(dt)-cellulose chromatography. the number average nucleotide length of the poly(a)-rna preparations i ...1976932004
single-stranded dna from oncornavirus-infected cells enriched in virus-specific dna sequences.we previously found that a minor fraction of single-stranded dna (ss-dna) isolated from native nuclear dna of normal chicken embryonic cells and cells of other species hybridized with bulk nuclear dna or cellular rna in great excess. at least one-third of ss-dna belonging to the nonrepetitious part of the cell genome could be hybridized to homologous rnas. in the present work, similar results were obtained with ss-dna from cells of chickens infected by avian myeloblastosis virus (amv). to invest ...1977198800
measurement of proviral genes in uninfected and avian myeloblastosis virus-infected cells by hybridization with 3h-labeled complementary dna probe excess.viral rna (vrna) from avian myeloblastosis virus or dna from virus-infected and uninfected cells was hybridized with [3h]dna complementary to viral rna ([3h]cdna) under conditions of [3h]cdna excess. when [3h]cdna was used to drive the hybridization reaction with vrna, a rate constant of 33.2 liters/mol-s was obtained. the same rate constant was obtained when vrna excess was used as the driver. the specific activities of the [3h]dna probe, estimated from kinetic measurements of the hybridization ...1977199736
[cellular contaminants and structural proteins of rous sarcoma virus (rsv), studied by polyacrylamide gel electrophoresis].the number of polypeptides in highly purified preparations of rsv, of two different subgroups, produced in culture, has been compared to the polypeptides present in the supernatant of uninfected cultures and processed in identical manner. the analysis of page-sds shows that from 13 to 18 polypeptides present in viral preparations may be cellular contaminants. fewer contaminating polypeptides are found in the myeloblastosis virus purified from plasma of chicken.1977199367
cyclophosphamide induced sensitivity against avian rna myeloblastosis virus in age-resistant hosts.the effect of cyclophosphamide administration on survival of 4- to 7-week-old chickens as well as on induction of leukemia after avian myeloblastosis virus (amv) injection was studied. the drug treatment alone did not cause any neoplastic effect in the birds during 4 months of observation. immediate application of amv to cyclophosphamide-pretreated age-resistant chickens induced acute myeloblastic leukemia in about 80 per cent of test animals. the sensitivity of chickens against amv, induced by ...1977201874
[revertase in myeloblasts of chickens infected with avian myeloblastosis virus].revertase present in the myeloblasts of chickens infected with avian myeloblastosis virus failed to synthetise dna in vitro on the endogenous viral template. enzyme inhibitors were not blocking this synthesis. it was rather impaired by incompletness of viral rna in immature virus particles.197772475
purification and further characterization of an rna-dependent dna polymerase from the allantoic fluid of leukosis-virus-free chicken eggs.the purification of an rna-dependent dna polymerase from the allantoic fluid of uninfected, embryonated chicken eggs is described in detail. comparison to the polymerase of avian myeloblastosis virus shows that the two enzymes are different with respect to ion concentrations for optimal reaction, response to increasing concentrations of substrate, thermal stability and protection from thermal inactivation by viral rna. it is concluded that the enzymes compared to each other are different protein ...197772662
homogeneity and complexity of avian oncornavirus proviral dna determined by molecular hybridization.the homogeneity of dna complementary to the 35s rna subunit of avian myeloblastosis virus (amv) has been demonstrated by single or multistep hybridization. for multistep hybridizations, 35s amv rna was preselected for its ability to hybridize either to unfractionated leukemic dna or to leukemic dna enriched for unique or for reiterated sequences. these experiments indicate that the viral genome is complementary to dna sequences with a low reiteration frequency. competition experiments confirm th ...1977191654
biological characterization of avian osteopetrosis.chicks infected as 12-day-old embryos with an end-point purified derivative of avian myeloblastosis virus developed a rapidly progressive osteopetrosis that manifested within 1 week of hatching. a detailed comparison of osteopetrotic chicks and normal hatchmates revealed the following. (i) osteopetrotic chicks exhibited a stunting syndrome, growing at a mean rate that was 26% of the control rats. (ii) at autopsy, the mass of the lymphoid organs was reduced, whereas the mass of the heart, pancrea ...1977197009
in vitro transformation with avian myelocytomatosis virus strain cmii: characterization of the virus and its target cells.avian myelocytomatosis virus strain cmii induced an in vitro transformation in cells from various hematopoietic tissues and could be quantitated by focus and soft agar colony assay techniques. the cmii-transformed bone marrow cells had a high proliferative capacity in comparison to uninfected controls. the cells closely resembled hematopoietic cells transformed by strain mc29 myelocytomatosis virus, but differed from avian myeloblastosis virus (amv)-transformed cells. they were phagocytic, becam ...197718625478
isolation of the proviral coding strand of avian myeloblastosis virus from leukemic chicken myeloblast by affinity chromatography. 1978210689
binding of trna to reverse transcriptase of rna tumor viruses.the interaction of trna with the reverse transcriptase (rna-dependent dna polymerase) of mammalian rna viruses, such as moloney murine leukemia virus and simian sarcoma virus, has been studied. whereas the purified reverse transcriptase of mammalian viruses sedimented in glycerol gradients as a globular protein with a molecular weight of 70,000, after interaction with trna the enzyme cosedimented with a protein of 150,000 molecular weight. the twofold increase in molecular weight could be a resu ...197877907
normal chicken cells (chf-) express a surface antigen which cross-reacts with determinants of the major envelope glycoprotein (gp85) of avian myeloblastosis virus. 197878565
virus-coded origin of a 32,000-dalton protein from avian retrovirus cores: structural relatedness of p32 and the beta polypeptide of the avian retrovirus dna polymerase.a 32,000-dalton protein (p32) located in avian retrovirus cores was immunoprecipitated from [35s]methionine-labeled avian myeloblastosis virus (amv) propagated in cultured chicken embryo fibroblast cells by an antiserum preparation (sarc iii) derived from tumor-bearing hamsters injected with cloned and passaged cells from an avian sarcoma virus-induced primary hamster tumor. since sarc iii serum apparently contained antibodies only to virus-coded proteins and not to chicken cellular proteins, th ...197881316
isolation and characterization of a virus-specific ribonucleoprotein complex from reticuloendotheliosis virus-transformed chicken bone marrow cells.chicken bone marrow cells transformed by reticuloendotheliosis virus (rev) produce in the cytoplasm a ribonucleoprotein (rnp) complex which has a sedimentation value of approximately 80 to 100s and a density of 1.23 g/cm3. this rnp complex is not derived from the mature virion. an endogenous rna-directed dna polymerase activity is associated with the rnp complex. the enzyme activity was completely neutralized by anti-rev dna polymerase antibody but not by anti-avian myeloblastosis virus dna poly ...197881319
synthesis of full length cdnas from four partially purified oviduct poly(a)-containing rna prepared from hen oviduct and centrifuged on an isokinetic sucrose gradient displays four peaks of optical absorbance. these have been identified by translation in vitro as lysozyme, ovomucoid, ovalbumin, and conalbumin mrnas. isolation and recentrifugation of the peaks results in partial purification of each mrna. molecular weights have been determined for the mrnas on agarose gels containing 20 mm methylmercury hydroxide. each mrna possesses a number of apparently ...1978632280
size and secondary structure of avian myeloblastosis virus associated ribosomal rna: comparison with cellular and precursor ribosomal rna.ribosomal rna isolated from ribosomes present inside avian myeloblastosis virus (amv) was characterized by electron microscopy using the formamide-urea spreading technique. the molecular weight and the secondary structures were compared with those of r-rna and precursor r-na isolated from host cells, the leukemic myeloblasts. the molecular weight of viral r-rna (1.62 +/- 0.18 x 10(6) and 0.69 +/- 0.10 x 10(6)) and the molecular weight of cellular r-rna (1.63 +/- 0.18 x 10(6) and 0.67 +/- 0.09 x ...1978205195
stimulation of sugar uptake and glycolysis in chicken embryo fibroblasts by the major glycoprotein from avian myeloblastosis virus.addition of purified major glycoprotein from avian myeloblastosis virus to growing or quiescent chicken embryo fibroblasts rapidly stimulates the rate of hexose transport and increases the lactic acid production. these stimulatory effects are dependent on the time of exposure and the dose of viral glycoprotein. in contrast, the glycoprotein only marginally affects hexose transport in chicken cells transformed by rous sarcoma virus. some effects of the glycoprotein on serum-starved quiescent cell ...1979223157
response of hemopoietic cells to avian acute leukemia viruses: effects on the differentiation of the target cells.chicken bone marrow cells were infected with three avian acute leukemia viruses (alv)--avian myeloblastosis virus (amv), myelocytomatosis virus strain mc29 and mill hill 2 virus (mh2)--and then cultured in agar in the presence of conditioned medium. under these conditions, it was found that very few cells served as target cells for these three viruses. density gradient separation showed that alv target cells were found primarily in the light density fractions and might be represented by cells co ...1979222465
reverse transcriptase from avian myeloblastosis virus.from lots of 20 to 30 g of avian myeloblastosis virus rna-dependent dna polymerase was obtained in preparations of purity greater than 95% by using a two-step column chromatographic procedure employing deae (de 52) and carboxymethylcellulose (cm 52.). yields of rna-dependent dna polymerase varied from approximately 20,000 to 35,000 u/g of virus. specific activity of the enzyme was about 35,000 to 60,000 u/mg of protein. free of detectable rnase activity, the product exhibited a molecular weight ...197985721
immunochemical studies of beef pancreas tryptophanyl-trna synthetase and its fragments. determination of the number of antigenic determinants and a comparison with tryptophanyl- trna synthetases from other sources and with reverse transcriptase from avian myeloblastosis virus.the immunoglobulin g (igg) fraction of the antiserum from rabbits immunized with homogeneous beef pancreas tryptophanyl-trna synthetase inhibits the enzyme activity in the reactions of both trnatrp aminoacylation and tryptophan activation. fab fragments of igg act in a similar way. common antigenic determinants have been detected in tryptophanyl-trna synthetases from beef, pig, chicken and rat livers using pure antibodies against beef pancreas tryptophanyl-trna synthetase. this observation indic ...197989031
[separation of cellular and viral dna polymerase from oncornavirus infected chicken cells].rna-directed dna polymerase was isolated from the liver, spleen, and myeloblasts of chickens that had been infected with virus of avian myeloblastosis. the enzyme was chromatographically purified from the myeloblasts and brought to about 1,000-fold concentration. the method consisted in cell fractionation, lysis of the microsomal fraction, chromatography on sephadex g-200 and phosphocellulose, as well as ultracentrifugation in the glycerol gradient. the cellular dna polymerases alpha and beta we ...197993956
immunodiffusion study on group-specific antigen of mc-29 chicken hepatoma.rabbit serum against crude mc-29 hepatoma extract does not contain anti-avian gs antibodies detectable by gel diffusion methods. rabbit serum containing antibodies against purified gs 1, gs 2, gs 3 and gs 4 antigens of avian myeloblastosis virus reveals gs 1 antigen in mc-29 hepatoma extract.197995333
thymic dependence of cell-mediated immunity to avian sarcomas in chickens. immunological characterization of a nonvirion antigen in virus-infected cells. 1979223766
characterization of an adenosine triphosphatase from myeloblasts infected with the avian myeloblastosis adenosine triphosphatase (atpase ec was partially purified from myeloblasts of chicken infected with the avian myeloblastosis virus and some of its molecular, catalytic and immunological properties were compared with that of the atpase purified from the virus. both the enzymes possessed almost same electrophoretic mobility, molecular weight, s20,w value, substrate specificity, metal-ion requirement, apparent km value and sensitivity to inhibitors and activator. evidence also indicate ...1979225174
an enzyme-linked immunosorbent assay for detecting avian leukosis-sarcoma viruses.immunoglobulins from antiserum raised against chromatographically purified avian myeloblastosis virus (amv) group-specific (gs) antigens were used in enzyme-linked immunosorbent assay (elisa). readily discernible color was produced with 2--3 ng of amv protein in microplate wells coated with 4 micrograms of salt-precipitated immunoglobulins. when a biological assay, i.e., phenotypic mixing (pm), was the criterion for the infectious status of specimens, the elisa consistently identified a greater ...1979230808
detection of avian oncovirus group-specific antigens by the enzyme-linked immunosorbent assay.a three-step sandwich enzyme-linked immunosorbent assay was developed for the detection of avian oncovirus group-specific (gs) antigens. the assay procedure was to coat the wells of microtitre plates with hamster anti-gs igg, react with crude or purified antigen and finally with hamster anti-gs igg linked to horseradish peroxidase. the sensitivity was 8 picograms (pg) of input avian myeloblastosis virus (amv) protein, with negligible background. as the elisa takes less than 2 h to perform, large ...19806245172
identification of the avian myeloblastosis virus genome. ii. restriction endonuclease analysis of dna from lambda proviral recombinants and leukemic myeoblast clones.two lambda proviral dna recombinants were characterized with a number of restriction endonucleases. one recombinant contained a complete presumptive avian myeloblastosis virus (amv) provirus flanked by cellular sequences on either side, and the second recombinant contained 85% of a myeloblastosis-associated virus type 1 (mav-1)-like provirus with cellular sequences adjacent to the 5' end of the provirus. comparing the restriction maps for the proviral dnas contained in each lambda hybrid showed ...19806253659
expression of endogenous avian myeloblastosis virus information in different chicken cells.uninfected chicken cells were found to contain endogenous avian myeloblastosis virus (amv)-specific information. different tissues from chicken embryos and chickens expressed different amounts of the amv-specific information. the endogenous amv-related rna was most abundant in bone marrow cells, which contained about 20 copies per cell. about 5 to 10 copies of amv endogenous rna per cell were found in embryonic yolk sac cells and bursa cells. the spleen, muscle, liver, and kidney cells of chicke ...19806255203
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 ...19806154153
genetic structure of avian myeloblastosis virus, released from transformed myeloblasts as a defective virus particle.chicken myeloblasts transformed by avian myeloblastosis virus (amv) in the absence of nondefective helper virus (termed nonproducer cells) were found to release a defective virus particle (dvp) that contains avian tumor viral gag proteins but lacks envelope glycoprotein and a dna polymerase. nonproducer cells contain a pr76 gag precursor protein and also a protein that is indistinguishable from the pr180 gag-pol protein of nondefective viruses. the rna of the dvp is 7.5 kilobases (kb) long and i ...19806159639
retroviral antigens on gs- chf- has recently been suggested that the endogenous retroviruses present in many different species might be involved during stimulation of the immune system of their hosts. we have now studied the expression of two avian retroviral antigens p27 and gp85 in chicken lymphoid cells by indirect immunofluorescence (iif) and by complement-dependent microcytotoxicity (cdm). we have now found that these viral antigens are expressed in peripheral blood leukocytes of adults and embryos and in splenic and b ...19806253834
cellular sequences are present in the presumptive avian myeloblastosis virus genome.ecori restriction endonuclease fragments from a lambda proviral dna hybrid containing the entire presumptive avian myeloblastosis virus (amv) provirus, and from a lambda proviral hybrid containing a partial myeloblastosis-associated virus type 1 (mav-1)-like provirus were compared by heteroduplex analysis. the cloned presumptive amv provirus was also analyzed by electron microscopy, using r-loop formation with purified 35s rna isolated from virions of the standard amv complex. the results indica ...19806254063
characterization of avian myeloblastosis-associated virus dna intermediates.the major species of unintegrated linear viral dna identified in chicken embryonic fibroblasts infected with either the avian myeloblastosis-associated viruses (mav-1, mav-2) or the standard avian myeloblastosis virus complex (amv-s) has a mass of 5.3 x 10(6) daltons. an additional minor dna component observed only in amv-s-infected cells has a mass of 4.9 x 10(6) daltons. the unintegrated linear viral dnas and integrated proviruses of mav-1 and mav-2 have been analyzed by digestion with the res ...19806246269
oncogenicity of three strains of avian leukosis virus in white leghorn chicks of bk line. 19806265807
identification of a proviral genome associated with avian myeloblastic leukemia.we have identified and isolated a presumptive leukemogenic provirus from myeloblasts of a chicken in which leukemia had been induced by avian myeloblastosis virus (amv). leukemic myeloblasts isolated from peripheral blood or from converted yolk sac cultures of various strains of chickens, regardless of the endogenous proviral content or amv pseudotype used for infection, contain an ecori 2.2-megadalton (mdai) and a hindiii 2.6-mdal proviral fragment. a proviral genome flanked by chicken dna sequ ...19806248880
pathology of chickens infected with avian nephoblastoma virus mav-2(n).a neophroblastoma-inducing myeloblastosis-associated virus, mav-2(n), derived from avian myeloblastosis virus was characterized with respect to biochemical composition and avian pathogenesis. purified fibroblast-grown virus contained the same size 35s ribonucleic acid and the same relative amounts of viral polypeptides as another myeloblastosis-associated virus inducing predominantly osteopetrosis mav-2(o). plaque-purified mav-2(n) induced a 76 to 93% incidence of nephroblastoma and a 3 to 50% i ...19806247276
activation of cellular genes by avian rna tumor viruses.we demonstrated previously that chicken embryo fibroblasts accumulate approximately 100 copies of embryonic globin rna after transformation by rous sarcoma virus. here we demonstrate that the globin gene in chicken embryo fibroblasts is activated by infection with two other oncogenic retroviruses, avian erythroblastosis virus and strain mc-29 of avian myeloblastosis virus, which contain transforming genes unrelated in nucleotide sequence content to each other or to the rous sarcoma virus src gen ...19806254077
virus-mediated abrogation of chicken lymphocyte responsiveness to mitogenic stimulus.we have found that various sorts of virus particles, including avian leukosis and sarcoma viruses, sendai virus, friend leukemia virus and murine mammary tumor virus, are able, upon coincubation with chicken peripheral lymphocytes and either concanavalin a (con a) or phytohemagglutinin (pha), to inhibit the mitogenic responses that normally follow. such inhibition is not dependent on the use of infectious virus, and can be documented by using particles whose infectivity has been abolished by irr ...19806255923
studies in amv dna. i. physical properties and sequence composition of dna present in amv virions (amv dna).the basic physical properties of amv dna (labeled with 3h-thymidine) as well as sequence homology between 3h-amv dna and viral or host cell genomes were investigated. it was found that native amv dna is in part single-stranded (20% of the total dna). using cscl density gradient centrifugation amv dna was separated into two bands with buoyant densities of 1.702 g/cm3 (l-amv dna) and 1.722 g/cm3 (h-amv dna) in the peak fractions. corresponding melting temperatures were estimated to be 82.0 degrees ...19806257200
inhibition of virion-associated reverse transcription by nucleoside triphosphatase in avian myeloblastosis virus.rna-dependent dna polymerase activity of avian myeloblastosis virions as measured by the incorporation of [3h]ttp into trichloroacetic acid-precipitable material was very low. this apparent low polymerase activity was observed with virions isolated either from leukemic chicken plasma or from the supernatant of cultured leukemic myeloblasts. the inhibition of reverse transcriptase activity was caused by nucleoside triphosphatase present in avian myeloblastosis virions and could be reversed by adp ...19806154806
recombinant plasmids containing avian vitellogenin structural gene sequences derived from complementary dna.purified mrna coding for chicken vitellogenin, a precursor of egg yolk proteins, was transcribed to complementary dna (cdnavit) with avian myeloblastosis virus (amv) reverse transcriptase. double-stranded cdna was synthesized with escherichia coli dna polymerase i (fragment a) using the self priming ability of the cdna. following s1 nuclease digestion the double-stranded cdna was inserted into the hind iii site of plasmid pbr322 using the poly(da) . poly(dt) tailing method, and the hybrid molecu ...19806986172
[dna polymerase in the microsomal fraction of the myeloblasts of chickens infected with avian myeloblastosis virus].only one dna polymerase is present in the microsomal fraction of the cells producing amv. chromatographically purified enzyme shows the properties of revertase, that is it transcribes in dna the information encoded in natural rna. the enzyme possesses identical chromatographic characteristics and the same template specificity as the enzyme isolated from pure amv virus. thus the virus enzyme and the cellular dna polymerase from the microsomal fraction cannot be differentiated on the basis of cert ...19807293688
identification of the avian myeloblastosis virus genome. i. identification of restriction endonuclease fragments associated with acute myeloblastic leukemia.the proviral dna of chicken peripheral blood leukemic myeloblasts was analyzed by restriction endonuclease digestion and southern blotting. two restriction endonuclease-generated fragments, an ecori 2.2-megadalton (md) and a hindiii 2.6-md fragment, were present upon enzyme cleavage of all leukemic myeloblast dna preparations in addition to endogenous or helper-specific fragments. neither of these fragments was derived from viral dna of the two known myeloblastosis-associated viruses (mav-1 and ...19806253658
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