title: Integrated state of oncornavirus DNA in normal chicken cells and in cells transformed by avian myeloblastosis virus.
abstract: 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 density equilibrium sedimentation, the viral DNA was present as linear, double-stranded molecules not separable from linear chicken DNA. After extraction by the Hirt procedure, the viral DNA precipitated with the high-molecular-weight DNA. After alkaline sucrose velocity sedimentation, the viral DNA cosedimented with the high-molecular-weight cellular DNA. The results indicate that in both types of cells studied, the oncornavirus-specific DNA sequences were linked by alkali stable bonds to nuclear cellular DNA of high molecular weight and did not appear to be present in free form of any size.
mesh_terms: D000818:Animals; D001354:Avian Leukosis Virus; D002250:Carbon Radioisotopes; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000032:analysis; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D004247:DNA / Q000032:analysis / Q000302:isolation & purification; D004272:DNA, Mitochondrial / Q000302:isolation & purification; D004279:DNA, Viral / Q000378:metabolism*; D005347:Fibroblasts; D007553:Isotope Labeling; D009693:Nucleic Acid Hybridization; D009858:Oncogenic Viruses; D011506:Proteins / Q000032:analysis; D012313:RNA / Q000032:analysis; D012367:RNA, Viral / Q000145:classification; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D004272:DNA, Mitochondrial; D004279:DNA, Viral; D011506:Proteins; D012367:RNA, Viral; D014316:Tritium; D012313:RNA; D004247:DNA