Molecular analysis of an unstable P element insertion at the singed locus of Drosophila melanogaster: evidence for intracistronic transposition of a P element.
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.
Hawley
R S
RS
Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 10461.
Steuber
R A
RA
Marcus
C H
CH
Sohn
R
R
Baronas
D M
DM
Cameron
M L
ML
Zitron
A E
AE
Chase
J W
JW
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
D004251:DNA Transposable Elements; D004247:DNA