Generation of new transforming viruses from SIRC cells "phenotypically transformed" in the medium with low concentrations of serum or calcium ions.

The work reported here demonstrates the possibility of rapid generation of highly transforming viruses from rabbit epithelial corneal cells (SIRC) originated from simian sarcoma associated virus (SSAV). The results of the experiments indicate a possible association of the phenomenon of "phenotypic transformation" with the expression of cellular genes with a potential transforming activity. SIRC/SSAV phenotypic transformation was induced by cultivation of these cells in the medium with a low concentration of serum or calcium ions. During subsequent infection of mink lung fibroblasts the authors succeeded in obtaining two new transforming SSAV isolates which induced transformation foci of various morphological types in cellular lines permissive for SSAV replication.