Influence of chromosomal position and copy number of a white-directed ribozyme gene on the suppression of eye pigmentation in Drosophila melanogaster.
Different strains of transgenic Drosophila melanogaster carrying one, two, or three copies of a heat-shock promoter 70 (hsp70)-driven catalytic antisense RNA gene, directed against the white gene, were investigated for the expression level of ribozyme RNA. It was found that the steady-state concentrations of the hammerhead ribozyme were proportional to the copy number of the genes and that the suppressive effect on eye pigment accumulation was dosage dependent. In a further experiment, a D. melanogaster strain, deficient in eye pigmentation caused by a deletion of the white gene, was used for P element-mediated germline transformation: the transposon used contained the hsp70-driven, white-directed ribozyme gene and, on the same DNA, the mini-white gene under its own promoter. The spatial coupling of the transcription of ribozyme and target RNA resulted in more effective ribozyme-mediated inhibition of eye pigmentation under heat-shock conditions. These effects were dependent on the chromosomal integration site of the transposon.
Heinrich
J C
JC
Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Crete, Greece.
Tabler
M
M
Louis
C
C
D000818:Animals; D030801:Animals, Genetically Modified; D002874:Chromosome Mapping; D004331:Drosophila melanogaster / Q000235:genetics*; D018628:Gene Dosage; D017344:Genes, Insect; D010857:Pigment Epithelium of Eye / Q000502:physiology*; D016372:RNA, Antisense / Q000235:genetics; D016337:RNA, Catalytic / Q000235:genetics*; D013489:Suppression, Genetic
D016372:RNA, Antisense; D016337:RNA, Catalytic