PROMOTER REGION OF THE DROSOPHILA-MELANOGASTER NORPA GENE

We have sequenced the 5'-flanking region of the Drosophila melanogaste r norpA gene and characterized its promoter. The potential promoter re gion, which was deduced from the determination of the transcription st art point (tsp), lacks a distinct TATA box sequence. Deletion analysis of the promoter region suggests that the minimal promoter necessary f or efficient expression of the gene is located between -138 (PstI) and +278 relative to the tsp. Within this minimal promoter region, at lea st two downstream regulatory elements responsible for the stimulation of gene expression seem to exist in the DNA fragments between +44 and +121 and between +214 and +278. Among these, the DNA fragment between +44 and +121 affects promoter activity more dramatically (about 6-7 fo ld). This DNA fragment contains the consensus promoter element previou sly reported to be important for photoreceptor cell-specific expressio n, and this promoter element seems to be working in the norpA gene exp ression.