Molecular Analysis of theDrosophilaCatalase Gene

The main objective of this study was to isolate and characterize the catalase gene and accompanyingcis-regulatory regions inDrosophila melanogaster.Genomic clones were obtained on the basis of cross-hybridization to catalase cDNA and a 7-kbSalI–KpnI fragment encompassing the catalase gene was introduced intoDrosophilaby P element-mediated transformation. A single transgene, when placed in a catalase null background, was sufficient to restore resistance to H2O2as well as reduce susceptibility to early death. DNA sequence of the catalase gene domain was obtained. This included 1365 bp of sequence upstream of the transcription initiation site and 1423 bp downstream of the termination codon. TheDrosophilacatalase gene is composed of 3 exons, encoding 19, 307, and 180 amino acids, which are separated by 3520- and 96-bp introns. Sequence analysis of the promoter domain is presented, revealing multiple sequence similarities between catalase and Cu,Zn superoxide dismutase promoter domains. Developmental RNA gel analysis shows that peaks of catalase mRNA accumulation correspond roughly with major peaks of ecdysone titer during third instar and pupal stages. Candidate ecdysone response element sequences are noted downstream of the catalase polyadenylation site.