A KP Element Inserted Between the Two Promoters of the Alcohol Dehydrogenase Gene of Drosophila melanogaster Differentially Affects Expression in Larvae and Adults
- Cite this article as:
- Wu, YH., Wilks, A.V. & Gibson, J.B. Biochem Genet (1998) 36: 363. doi:10.1023/A:1018749513875
- 30 Downloads
An allele of the Drosophila melanogaster alcoholdehydrogenase (Adh) gene has a 1.15-kb KP elementinserted, in the same orientation as Adh transcription,five nucleotides upstream of the distal transcription start site. The target site-GTCCAAGT — inAdh between nucleotides –13 and –6 isduplicated at both ends of the insertion. Adult flieswith either one or two copies of the allele have lessthan 12% of the alcohol dehydrogenase (ADH) activity of thecontrols. Activity levels are also reduced in larvae,but by a much smaller amount. Quantitative Northernanalyses showed that the low activity level in adults was caused by reduced transcript levels fromthe distal promoter. 5′ RACE experiments indicatedthat adult transcripts were mostly initiated downstreamof the distal promoter but some skipped the first adult exon. In late third-instar larvae thetranscripts present were from the proximal promoter.After the KP element was deleted by an appropriatebreeding program, the distal transcript increased inadults to the control level, but ADH activityincreased to only 50% of the control. No nucleotidechanges were found in the gene that could explain thisdifference.