The Chick Fibroblast Cell Surface after Transformation by Rous Sarcoma Virus

As a preliminary to immunological and physiological studies, we have been attempting to define major biochemical and biophysical changes on the cell surface following transformation. Many of our initial comparisons were carried out with established lines (Wu et al. 1969). However, a concern in such studies is the known aneuploidy of continuous lines and the tendency toward genetic drift under the twin pressures of unstable chromosome complement and continuous passaging in vitro. These objections can be overcome by using a system in which a diploid population of cells can be rapidly converted from the normal to the transformed phenotype by use of a transforming virus and corresponding virus mutants with a temperature-sensitive transforming function. We have used the ts 68 mutant of the Schmidt-Rupin strain of Rous sarcoma virus to transform secondary chick embryo fibroblasts. Fibroblasts so infected have normal morphology at 41°C but are rapidly converted to a transformed...