title: Induction of type C viruses in cultured guinea pig cells.
abstract: Particles morphologically resembling type C viruses were activated by bromodeoxyuridine (BUdR; 10(-4) M) treatment of cultured guinea pig cells. Virus particles were isolated from the cells of normal and leukemic strain 2 and random-bred guinea pigs (adult and embryonic). Immature virus particles with electron-lucent cores were found in the cytoplasmic matrix. The mature particles with electron-dense cores were found outside the cells and some appeared in the process of budding from the plasma membrane. The peak of virus production was observed within 4 days of BUdR treatment. When compared to the amount of virus produced in darkness, visible light enhanced virus production, whereas exposure of BUdR-treated cells to UV light either had no effect or inhibited virus production. Virus particles had a density of 1.16 gm/ml, possessed an oncornavirus-specific reverse transcriptase, and contained a large-molecular-weight RNA (65-70S) which dissociated into 36S subunits after heat denaturation. The BUdR-activated virus particles, therefore, possessed the morphological, biophysical, and biochemical characteristics of type C oncornaviruses.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002462:Cell Membrane / Q000382:microbiology; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D003593:Cytoplasm / Q000382:microbiology; D006168:Guinea Pigs; D007181:Inclusion Bodies, Viral; D007668:Kidney; D007942:Leukemia, Experimental; D008027:Light; D008854:Microscopy, Electron; D008970:Molecular Weight; D009132:Muscles; D009858:Oncogenic Viruses / Q000254:growth & development*; D012328:RNA Viruses / Q000254:growth & development*; D012367:RNA, Viral / Q000032:analysis; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D011830:Radiation Effects; D012190:Retroviridae / Q000032:analysis / Q000201:enzymology / Q000254:growth & development; D013154:Spleen; D014466:Ultraviolet Rays; D014779:Virus Replication / Q000187:drug effects / Q000528:radiation effects
chemical_list: D012367:RNA, Viral; D012194:RNA-Directed DNA Polymerase; D001973:Bromodeoxyuridine