title: Molecular analysis of an unstable P element insertion at the singed locus of Drosophila melanogaster: evidence for intracistronic transposition of a P element.
abstract: In a companion study, a number of P element insertions into the singed locus were characterized. Here is reported a detailed analysis of the structure and mutability of another P element insertion at sn, known as sncm. Under conditions which mobilize P elements, sncm mutates at high frequency to both wild-type (sn+) and to a much more extreme allele (snext). Wild-type revertants appear to represent precise or nearly precise excisions of the P element. Certainly two, and most likely all five, of the snext alleles studied result from the insertion of a duplicate copy of this P element into a nearby site in an inverted orientation. We propose a model in which both the sn+ and snext mutational events can be explained by excision of the P element from one chromatid followed by reintegration into the sister chromatid at a nearby site (intracistronic transposition). Finally, it is shown that the snext alleles are themselves unstable and the structure of a resulting chromosome aberration is examined.
authors.affiliation: Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461.
authors.forename: R S
authors.initials: RS
authors.lastname: Hawley
authors.forename: R A
authors.initials: RA
authors.lastname: Steuber
authors.forename: C H
authors.initials: CH
authors.lastname: Marcus
authors.forename: R
authors.initials: R
authors.lastname: Sohn
authors.forename: D M
authors.initials: DM
authors.lastname: Baronas
authors.forename: M L
authors.initials: ML
authors.lastname: Cameron
authors.forename: A E
authors.initials: AE
authors.lastname: Zitron
authors.forename: J W
authors.initials: JW
authors.lastname: Chase
mesh_terms: D000483:Alleles; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D004247:DNA / Q000302:isolation & purification; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D005796:Genes; D007120:Immunochemistry; D008855:Microscopy, Electron, Scanning; D009154:Mutation
chemical_list: D004251:DNA Transposable Elements; D004247:DNA