[Analysis of the mutations induced by alkylating compounds in Drosophila sperm. II. The nature of the chemically induced unstable locus states in Drosophila melanogaster].

Two types of unstable visible mutations induced by ethylnitrosourea and ethylmethanesulfonate were detected and studied. In cases of replicating instability, mutations newly emerging in the offspring of a single male were allelic. They were located either in a single site or in different sites of the gene. Substitution of autosomes in unstable lines was followed by stabilization of both normal and mutant phenotype in two cases of replicating instability.