[Saccharomyces cerevisiae mutants characterized by increased induced mutagenesis. II. Genetic analysis of mutants]

Induction of forward adenine-dependent (Ade+----Ade-) mutations by HAP was used to analyse genetically yeast mutants with enhanced induced mutagenesis. Three mutations studied in detail segregated as a single mendelian trait and composed independent complementation groups (HIM1, HIM2, HIM3). the him1-1 mutation was centromere-linked, the him3-1 and him2-1 mutations being not. All three mutations did not show any cross-linkage. Uracil-DNA glycosylase activity was determined in crude cell extract from wild type strain and him mutants; no detectable differences were observed.