| mutations within the 5' half of the avian retrovirus mc29 v-myc gene alter or abolish transformation of chicken embryo fibroblasts and macrophages. | avian myelocytomatosis virus mc29 induces a wide variety of neoplastic diseases in infected birds and transforms cells of the macrophage lineage as well as fibroblasts and epithelial cells. a biological and biochemical analysis, carried out on a series of in-frame insertion and deletion mutations within the gag-myc gene of mc29, revealed several mutations within the 5' portion of the v-myc gene that encode proteins either completely defective for transformation or compromised in their ability to ... | 1992 | 1313895 |
| site-directed mutagenesis of the gag-myc gene of avian myelocytomatosis virus 29: biological activity and intracellular localization of structurally altered proteins. | transfection of chicken embryo cells with pmc29, a plasmid vector containing the sequences for the acute transforming virus mc29, and a cloned transformation-defective helper virus, p delta mst, resulted in morphological transformation, the synthesis of p110gag-myc (the product of the gag-myc oncogene), and the production of infectious virus. mc29 mutants bearing site-directed deletions within the gag-specific sequences or within the middle portion of the myc sequences efficiently induced transf ... | 1986 | 3018283 |
| two virus-specific rna species are present in cells transformed by defective leukemia virus ok10. | ok10 is a defective leukemia virus which shares some biological and biochemical properties of avian myelocytomatosis virus (mc29). we investigated the pattern of transcription of ok10 in both quail and chicken cells. in both cell types, ok10 produced two polyadenylated rna species of 8.6 and 3.5 kilobases, which both contained sequences derived from the 5' end of the genome and also the presumed transforming gene (myc). this is a novel form of expression for defective leukemia viruses of the mc2 ... | 1981 | 6270383 |
| 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 |
| expression of c-myc changes during differentiation of mouse erythroleukaemia cells. | the transforming gene of avian myelocytomatosis virus mc29, v-myc, causes a variety of malignancies in chickens. a cellular homologue, c-myc, has been implicated in b-cell malignancies in mice and humans but is also expressed in many normal cell types and may be important in the control of normal cell proliferation. c-myc is highly conserved in vertebrates. we have been investigating the relationship between c-myc expression and the terminal differentiation of cultured mouse erythroleukaemia (me ... | 1984 | 6462247 |
| pathogenicity of avian myelocytomatosis virus mc29 in two lines of chickens. | the pathogenicity of avian myelocytomatosis virus mc29 was studied in f1 hybrids of two prague inbred lines of chickens-cc xia (b4/b7 genotype) and cb x ia (b12/b7 genotype). a shorter latent period and a higher mortality was found in the cc x ia chickens. in most chickens of this group, subperiosteal accumulations of primitive cells on the ribs, sternum and pelvic bones were observed, which were never detected in the cb x ia chickens. unlike the typical myelocytomatosis, however, most of these ... | 1993 | 18671019 |
| association of gag-myc proteins from avian myelocytomatosis virus wild-type and mutants with chromatin. | the localization of the transformation-specific proteins was analyzed in quail embryo fibroblast cell lines transformed by wild-type avian myelocytomatosis virus mc29 and by three of its deletion mutants, q10a , q10c , and q10h , with altered transforming capacities, and in a chicken fibroblast cell line transformed by the avian erythroblastosis virus (aev). these viruses code for polyproteins consisting of part of the gag gene and of a transformation-specific region, myc for mc29 and erb a for ... | 1982 | 6329716 |
| infectivity of avian myelocytomatosis virus mc29 in rats. | mc29 virus was tested for the ability to infect rat tissues in vivo. as a virus source the virus-productive chicken cell line pr-2 was used. adult rats treated with the combination of dietary phenobarbital, 2-acetylaminofluorene and partial hepatectomy were injected with the viral preparation via the mesenteric vein. after a period of four months the presence of the viral genome in rat spleen and liver was detected by cocultivation of these tissues with chicken embryo cells or rav-49 preinfected ... | 1983 | 6318133 |
| a recovered avian myelocytomatosis virus that induces lymphomas in chickens: pathogenic properties and their molecular basis. | the avian myelocytomatosis virus mc29 induces neoplastic diseases in chicken, including myelocytomas and tumors of kidney and liver, which are due to the action of the v-myc gene. however, mc29 has never been reported to cause lymphoid tumors, the disease associated with activation of the c-myc gene by the insertion of a lymphoid leukosis virus genome. we have analyzed a recovered mc29 virus, hbi, which has a myc gene containing c-myc sequences, acquired by recombination with the cellular gene, ... | 1983 | 6317183 |
| nucleotide sequence analysis of the chicken c-myc gene reveals homologous and unique coding regions by comparison with the transforming gene of avian myelocytomatosis virus mc29, delta gag-myc. | myelocytomatosis virus mc29 is a defective avian retrovirus with a hybrid transforming gene (delta gag-myc) consisting of a 1,358-base pair (bp) sequence from the retroviral gag gene and a 1,568-bp sequence (v-myc) shared with a cellular locus, termed c-myc. we have subjected to sequence analysis 2,735 bp of the cloned c-myc gene, which includes the v-myc-related region of 1,568 bp, an intervening sequence of 971 bp, and unique flanking sequences of 45 bp and 195 bp at the 5' and 3' ends, respec ... | 1983 | 6300896 |
| altered pathogenicity of avian myelocytomatosis (mc29) viruses with mutations in the v-myc gene. | avian myelocytomatosis virus mc29 inoculated into the wing web of 1-day-old brown leghorn chickens causes a high incidence of tumors, predominantly endotheliomas that are apparently induced directly by the action of the viral myc gene. mutants of mc29, in which portions of the v-myc gene have been deleted and which have reduced ability to transform macrophages in vitro, induce few tumors, among which lymphomas and osteopetrosis predominate. analysis of lymphomas from birds infected with mutant m ... | 1983 | 6297150 |
| recovery of myc-specific sequences by a partially transformation-defective mutant of avian myelocytomatosis virus, mc29, correlates with the restoration of transforming activity. | avian myelocytomatosis virus mc29 transforms fibroblasts and macrophages in vitro. recently we isolated three deletion mutants of mc29 that have a decreased ability to transform macrophages while retaining their capacity to transform fibroblasts. one of these mutants, mc29 td10h, on passage through chicken embryo cultures gave rise to a recovered virus mc29 10h b1, which has regained the ability to transform macrophages efficiently. immunoprecipitation analysis of mc29 10h b1-infected cells reve ... | 1982 | 6294662 |
| isolation and characterization of c-myc, a cellular homolog of the oncogene (v-myc) of avian myelocytomatosis virus strain 29. | the chicken genome contains nucleotide sequences homologous to transforming genes (oncogenes) of a number of avian retroviruses. we have isolated chicken dna (c-myc) that is homologous to the oncogene (v-myc) of the avian myelocytomatosis virus mc29 and have compared the structures of the cellular and viral genes. results from restriction endonuclease mapping of c-myc and from analysis of heteroduplexes between the dnas of the cellular and viral genes show that c-myc is homologous to 1,500 nucle ... | 1982 | 6284994 |
| differential effects of transforming avian rna tumor viruses on avian macrophages. | functionally differentiated chicken macrophages were derived by in vitro differentiation of embryonic yolk sac cells and were characterized by several macrophage-specific cell markers. uniform, infected, virus-producing cultures were obtained after exposure of these macrophages to avian myoblastosis virus (amv), avian myelocytomatosis virus (mc29), myeloblastosis-associated virus (mav-2), and prague strain of rous sarcoma virus (pr-b rsv). both amv and mc29 induced morphological transformation t ... | 1981 | 6267600 |
| isolation of antibodies specific for avian viral and cellular myc proteins. | the myc gene has been implicated in the genesis of various neoplasms in birds, mice, and humans and was originally identified as the cellular homologue of the transforming gene (v-myc) of the avian myelocytomatosis virus mc29. for specific antisera to be obtained for the myc gene product, a bacterial expression vector was constructed in which the coding sequences for approximately 20 kd of mc29 p110gag-myc (amino acid residues 502 to 678) were placed between the coding sequences for the amino te ... | 1985 | 2997537 |
| c-myc gene is transcribed at high rate in g0-arrested fibroblasts and is post-transcriptionally regulated in response to growth factors. | there is increasing evidence that at least some of the cellular homologues to retroviral oncogenes (c-onc or proto-oncogenes) are directly linked to the control of cell growth (for a review see ref. 1). among these, c-myc, the cellular homologue to the avian myelocytomatosis virus (mc29) oncogene, has been shown to express high levels of mrna during early g0/g1 phase after mitogenic stimulation of t lymphocytes by concanavalin a or of fibroblasts by platelet-derived growth factor (pdgf) or serum ... | 2011 | 3900742 |