Cytogenetic Evolution of Ehrlich Ascites Tumor in Rats. A Chromosome-Banding Study

Abstract

The injection of Ehrlich tumor cells into normal and immunosuppressed rats induced a transitory ascitic tumor. In an initial stage only Ehrlich metaphases were observed. The incidence of rat metaphases, which appeared later on, increased gradually reaching 100 % in a stage when neither the viability nor the tumorigenicity of the Ehrlich cells were significantly modified. No mouse-rat hybrid cells were observed. The results suggest that cell hybridization may be essential for the ‘naturalization’ of a heterologous tumor.