Fig. 1.

Genomic organization and deletion analysis of theDps locus. The genomic organization of theDps gene was determined by sequencing genomic DNA obtained from a P1 clone (#DS03069; Berkeley DrosophilaGenome Project) and from genomic DNA obtained after plasmid rescue from the P4 insertion line (GenBank accession number, AF093402) as described (Pirrotta, 1986). The Dps gene is flanked on either side by the genes encoding lipoic acid synthase (accession numbers, AA820940and AA201873) and 50 S ribosomal protein L15 (clone name, GM01846).Dps is comprised of nine exons (boxes) separated by eight introns. The location of an alternative splice site that gives rise to two dps (dpsa1 and dpsa2) isoforms is shown (hatchedbox). The P-element insertion P4 used to generate Dps deletions is shown. Overlapping deletions in Dps were generated by imprecise excision of the P-element P4 and are indicated by dashedlines. The 5′ and 3′ deletion break points were determined by a combination of Southern blot analysis using several restriction enzyme sites and sequencing of the break points from genomic DNA obtained from the deletion mutants, W20, W6, and W11.