Abstract
Serially subcultivated Balb/c mouse embryo cells pass through a non-dividing or amitotic phase prior to becoming an established, growing cell line (Aaronson & Todaro, 1968; Baker & Simons, 1971). Cells in the amitotic phase are not visibly transformed by murine sarcoma virus-Harvey (MSV-H), although there is a low level of replication of the virus (Baker & Simons, 1971). DNA synthesis and cell division are initiated in the amitotic cells by infection with SV 40 (Baker, Simons & Rankin, 1972). The amitotic cells are particularly susceptible to SV 40, 60% of the cells synthesizing DNA by 48 h after infection (Baker et al. 1972). Moreover, simultaneous infection of amitotic cells with SV 40 and MSV-H results in extensive cellular transformation and MSV replication (Baker et al. 1972). This communication describes some of the properties of cells derived from amitotic cell cultures infected simultaneously with SV 40 and MSV-H.
* Present address: Tobacco Research Council Laboratories, Otley Road, Harrogate, Yorkshire, England.