Characterization of two Drosophila melanogaster cytochrome c genes and their transcripts

Analysis of total Drosophila melanogaster DNA by genomic blot hybridization indicates that two cytochrome c-like sequences exist in the Drosophila genome. These two sequences, DC3 and DC4, have been isolated from a Charon 4A-D. melanogaster genomic library. DC3 and DC4 are located within a 4 kb region of DNA, at position 36A 10-11, on the left arm of chromosome 2. The nucleotide sequence of these two clones has been determined. Both DC3 and DC4 can encode functional cytochrome c proteins. The polypeptide sequences predicted by these two genes, however, differ at 32 amino acid residues. DC4 is expressed at varying, but relatively high levels throughout Drosophila development. In contrast, DC3 is expressed at constant, but relatively low levels throughout development.