Enzyme-activity mutants in Mus musculus. I. Phenotypic description and genetic characterization of ethylnitrosourea-induced mutations

The specific activity of erythrocyte enzymes was measured to detect gene mu tations in F-1-offspring of male mice treatment with different doses (80, 1 60, or 250 mg/kg body weight) of ethylnitrosourea (ENU). Altogether 13,230 offspring were screened for 10 enzyme activities. Mutants with reduced acti vity as well as mutants with enhanced activity were found. Of the 36 indepe ndently observed mutations, 20 were homozygous lethal. Genetic and biochemi cal characterizations were routinely performed. These mutants provide insig ht into the mechanism of ENU mutagenesis and can serve as models for struct ure-function studies of the corresponding enzymes.