title: Identification of trans-dominant modifiers of Prat expression in Drosophila melanogaster.
abstract: The first committed step in the purine de novo synthesis pathway is performed by amidophosphoribosyltransferase (EC 2.4.2.14) or Prat. Drosophila melanogaster Prat is an essential gene with a promoter that lacks a TATA-box and initiator element and has multiple transcription start sites with a predominant start site. To study the regulation of Prat expression in the adult eye, we used the Prat:bw reporter gene, in which the Prat coding region was replaced with the brown (bw) coding region. The pale-orange eye color of a single copy of Prat:bw prompted us to use a multicopy array of Prat:bw that was derived using P transposase mutagenesis and produces a darker-orange eye color in a bw(D); st genetic background. We used a 13-copy array of Prat:bw as a tool to recover dominant EMS-induced mutations that affect the expression of the transgene. After screening 21,000 F(1)s for deviation from the orange eye color, we isolated 23 dominant modifiers: 21 suppressors (1 Y-linked, 5 X-linked, 4 2-linked, and 11 3-linked) and 2 enhancers (1 2-linked and 1 3-linked). Quantification of their effect on endogenous Prat gene expression, using RT-PCR in young adult fly heads, identifies a subset of modifiers that are candidates for genes involved in regulating Prat expression.
authors.affiliation: Department of Biology, University of New Brunswick, Fredericton, New Brunswick E3B 6E1, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Malmanche
authors.forename: Denise V
authors.initials: DV
authors.lastname: Clark
mesh_terms: D000582:Amidophosphoribosyltransferase / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D002874:Chromosome Mapping; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005123:Eye / Q000166:cytology / Q000378:metabolism; D005127:Eye Color / Q000235:genetics; D005786:Gene Expression Regulation; D005799:Genes, Dominant; D017344:Genes, Insect; D017930:Genes, Reporter; D016153:Genes, Suppressor; D008040:Genetic Linkage; D016254:Mutagenesis, Insertional; D009153:Mutagens / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D019076:Transgenes; D019895:Transposases / Q000235:genetics; D014921:Wings, Animal / Q000033:anatomy & histology
chemical_list: D029721:Drosophila Proteins; D009153:Mutagens; D015534:Trans-Activators; D005020:Ethyl Methanesulfonate; D000582:Amidophosphoribosyltransferase; D019895:Transposases