title: Mutations induced at the white and vermilion loci in Drosophila melanogaster.
abstract: The white and vermilion loci in D. melanogaster were selected as target genes for the study of the mutational specificity of ionizing radiation and N-ethyl-N-nitrosourea (ENU) in a whole organism. Analysis of X-ray- and neutron-induced white mutants by a combination of genetic and molecular techniques showed that ionizing radiation induces primarily break-type mutations against a repair-proficient background, the majority of these alterations being deletions. Both very large multi-locus deficiencies and deletions of only a few base pairs were observed. These small deletions are flanked by repeats of 2-3 nucleotides, one copy of which is retained at the new junction. Presumably these small repeats are involved in the generation of the X-ray-induced deletions. In excision-repair-deficient mus201D1 flies, the frequency of whole-body white mutants recovered after X-ray irradiation is the same as in the wild-type strain. The percentage of mosaic mutations, however, is enhanced by a factor 3-4. Analysis by blot hybridization of ENU-induced white mutants strongly indicates that most mutations are due to base-pair changes. This was confirmed by sequence analysis of 25 ENU-induced vermilion mutants. In all mutants the alterations are due to base-pair changes, the majority being GC to AT transitions (61%).
authors.affiliation: Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Pastink
authors.forename: C
authors.initials: C
authors.lastname: Vreeken
authors.forename: E W
authors.initials: EW
authors.lastname: Vogel
authors.forename: J C
authors.initials: JC
authors.lastname: Eeken
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004331:Drosophila melanogaster / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects*; D005038:Ethylnitrosourea / Q000494:pharmacology; D005796:Genes / Q000187:drug effects / Q000528:radiation effects*; D008969:Molecular Sequence Data; D009154:Mutation; D009502:Neutrons; D015183:Restriction Mapping; D014965:X-Rays
chemical_list: D005038:Ethylnitrosourea