Preferential transposition of Drosophila P elements to nearby chromosomal sites.
Two different schemes were used to demonstrate that Drosophila P elements preferentially transpose into genomic regions close to their starting sites. A starting element with weak rosy+ marker gene expression was mobilized from its location in the subtelomeric region of the 1,300-kb Dp1187 minichromosome. Among progeny lines with altered rosy+ expression, a much higher than expected frequency contained new insertions on Dp1187. Terminal deficiencies were also recovered frequently. In a second screen, a rosy(+)-marked element causing a lethal mutation of the cactus gene was mobilized in male and female germlines, and viable revertant chromosomes were recovered that still contained a rosy+ gene due to an intrachromosomal transposition. New transpositions recovered using both methods were mapped between 0 and 128 kb from the starting site. Our results suggested that some mechanism elevates the frequency 43-67-fold with which a P element inserts near its starting site. Local transposition is likely to be useful for enhancing the rate of insertional mutation within predetermined regions of the genome.
Howard Hughes Medical Institute Research Laboratories, Carnegie Institution of Washington, Baltimore, Maryland 21210.
J
J
Tower
G H
GH
Karpen
N
N
Craig
A C
AC
Spradling
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002875:Chromosomes; D004251:DNA Transposable Elements / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D005804:Genes, Lethal; D017403:In Situ Hybridization; D008297:Male; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011995:Recombination, Genetic; D017384:Sequence Deletion
D004251:DNA Transposable Elements