Stimulation of DNA Synthesis and Enhancement of Murine Sarcoma Virus Replication in Mouse Embryo Cells by SV 40

Abstract

Mouse embryo cells maintained on a rigid subculture regime undergo a rapid decline in growth rate leading to a period of negligible growth. Eventually the cells recommence growth and become established in vitro (Todaro & Green, 1963; Aaronson & Todaro, 1968; Baker & Simons, 1971). A very small percentage of cells in the non-dividing phase incorporate [³H]-thymidine and cells in this phase are not transformed by murine sarcoma virus (Baker & Simons, 1971). Treatment with colchicine does not result in the detection of metaphases and cells in this phase have been termed ‘amitotic’ (Baker & Simons, 1971).