title: Modified P elements that mimic the P cytotype in Drosophila melanogaster.
abstract: 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.
authors.affiliation: Department of Entomology, University of Illinois, Urbana 61801.
authors.forename: H M
authors.initials: HM
authors.lastname: Robertson
authors.forename: W R
authors.initials: WR
authors.lastname: Engels
mesh_terms: 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
chemical_list: D004251:DNA Transposable Elements; D012097:Repressor Proteins