Reversion of a gypsy-induced mutation at the yellow (y) locus of Drosophila melanogaster is associated with the insertion of a newly defined transposable element.
To understand the molecular basis of the phenotype of gypsy-induced mutations, we have analyzed the structure of phenotypic revertants of the y2 allele, which is caused by the insertion of the gypsy element into the 5' region of the yellow (y) locus. Seven spontaneous revertants examined fall into two different classes. Three of these revertants arose by homologous recombination between the two gypsy long terminal repeats (LTRs), leaving behind a solo LTR. Four additional revertants contain an intact 3' LTR and half of the 5' LTR, but the central portion of gypsy has been replaced by a different 6.5-kilobase transposable element that contains a poly(A) tail. These results suggest that the mutagenic effect of the gypsy element is not due to its insertion into sequences necessary for transcription or to the distancing between the yellow promoter and remote regulatory sequences but is a consequence of idiosyncratic properties of the element itself.
Geyer
P K
PK
Department of Biology, Johns Hopkins University, Baltimore, MD 21218.
Green
M M
MM
Corces
V G
VG
D000818:Animals; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D005786:Gene Expression Regulation; D009154:Mutation; D011679:Pupa; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D014158:Transcription, Genetic
D004251:DNA Transposable Elements; D012333:RNA, Messenger; D004262:DNA Restriction Enzymes