Modified P elements that mimic the P cytotype in Drosophila melanogaster.
Activity of the P family of transposable elements in Drosophila melanogaster is regulated primarily by a cellular condition known as P cytotype. It has been hypothesized that P cytotype depends on a P element-encoded repressor of transposition and excision. We provide evidence in support of this idea by showing that two modified P elements, each with lesions affecting the fourth transposase exon, mimic most of the P cytotype effects. These elements were identified by means of two sensitive assays capable of detecting repression by a single P element. One assay makes use of cytotype-dependent gene expression of certain P element insertion mutations at the singed bristle locus. The other measures suppression of transposase activity from the unusually stable genomic P element, delta 2-3(99B), that normally produces transposase in both germinal and somatic tissues. The P cytotype-like effects include suppression of snw germline hypermutability, snw somatic mosaicism, pupal lethality, and gonadal dysgenic sterility. Unlike P cytotype, however, there was no reciprocal cross effect in the inheritance of repression.
Robertson
H M
HM
Department of Entomology, University of Illinois, Urbana 61801.
Engels
W R
WR
D000483:Alleles; D000818:Animals; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics*; D005786:Gene Expression Regulation; D007246:Infertility; D009030:Mosaicism; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics
D004251:DNA Transposable Elements; D012097:Repressor Proteins