RT Journal Article SR Electronic(1) A1 Sharon, NehamaYR 1971 T1 In vitro Transformation of Primary and Continuous Rat Fibroblasts by Rous Sarcoma Virus (schmidt-ruppin) JF Journal of General Virology, VO 13 IS 2 SP 189 OP 192 DO https://doi.org/10.1099/0022-1317-13-2-189 PB Microbiology Society, SN 1465-2099, AB SUMMARY In vitro transformation of rat fibroblasts by the schmidt–ruppin strain of Rous sarcoma virus is described. Primary rat embryo fibroblasts were transformed in 2 to 6 weeks after infection with the virus. The transformed cells were large, refractile and polygonal in appearance and produced multilayer colonies. Injection of the transformed cells to young and weanling Sprague–Dawley rats induced fibrosarcomas. The continuous cell line of rat fibroblasts was transformed by Rous sarcoma virus (schmidt–ruppin) after 14 to 25 weeks. The transformation developed gradually from 1 or 2 islands of transformed cells per culture to a solid sheet of transformed cells. Cell cultures initiated tumours in young and weanling rats at the site of injection. Tumours grew slowly in weanling rats, while younger animals died from large tumours. These differences between young and old rats may reflect the immunological status of the host and/or the decrease in susceptibility of host cells to transformation by inoculated cell cultures., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-13-2-189