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).