A method to detect tumors and presumed somatic mutations in mice

A method was tested to detect both tumors and somatic mutations in mice. When HT-A/J F1 embryos were treated with ethylnitrosourea on day 11 of gestation, a single injection was enough to induce tumors and presumed somatic mutations of coat color in significantly high incidence. Urethane, treated in a similar way, induced somatic mutations and malformations in the offspring. Tumor incidence was also increased but was not significantly different from controls. Treatment on day 13 was too late to induce somatic mutations and malformations, while high incidence of tumors were induced.