Dose response of monoclonal tumor induction with 3-methylcholanthrene in mosaic mice

Inductions of monoclonal tumors, as judged by their single phenotype of phosphoglycerate kinase, in mice with X-chromosome inactivation mosaicism, were observed after s.c. injection of doses of 3-methylcholanthrene of 0.005 to 2 mg/mouse. The tumors induced (79% fibrosarcomas) exhibited the single-enzyme phenotype with 93% frequency at the lowest dose and with 57% frequency at the highest dose, indicating the dependence of monoclonal tumor induction on the dose of carcinogen.