title: Three new cases of R-type virus-like particles in hamster tumours.
abstract: R-type virus-like particles (VLP) in fibrosarcoma and myeloid tumour induced in hamsters with the myeloleukaemic virus of Graffi and in hamster embryonic fibroblasts infected with the lympholeukaemic virus Ly/Ya are described. The particles are found in the cysternae of the rough surface endoplasmic reticulum (RER). The VLP are classified as endogenous virus (EV) whose expression is determined by the initial infection with murine leukaemia virus (MLV).
authors.affiliation: Institute of General and Comparative Pathology, Bulgarian Academy of Sciences, Sofia.
authors.forename: R
authors.initials: R
authors.lastname: Roussev
authors.forename: M
authors.initials: M
authors.lastname: Polianova
authors.forename: R
authors.initials: R
authors.lastname: Toshkova
mesh_terms: D000818:Animals; D006224:Cricetinae; D004721:Endoplasmic Reticulum / Q000382:microbiology; D005347:Fibroblasts / Q000382:microbiology; D005354:Fibrosarcoma / Q000382:microbiology*; D009052:Leukemia Virus, Murine; D007942:Leukemia, Experimental / Q000382:microbiology*; D008647:Mesocricetus; D008854:Microscopy, Electron; D009368:Neoplasm Transplantation; D012192:Retroviridae Infections / Q000382:microbiology*; D014407:Tumor Cells, Cultured; D014412:Tumor Virus Infections / Q000382:microbiology*; D014771:Virion / Q000302:isolation & purification* / Q000648:ultrastructure