Genetic instability in Drosophila melanogaster: De novo induction of putative insertion mutations

Abstract

The capacity of a so-called male recombination (MR) chromosome in D. melanogaster to generate mutations at 14 X-chromosome loci specifying visible phenotypes was investigated. Appreciable increases in mutation were found at 3 loci y, sn, and ras. Tests of representative mutants generated at each locus establish all to be putative insertion mutants, as judged by their spontaneous mutability. Insertion mutation production may be a general function of MR chromosomes. The relationship of the MR chromosomes to established insertion elements (IS and Mu) is discussed.