STRUCTURE OF DROSOPHILA-VIRILIS GLYCEROL-3-PHOSPHATE DEHYDROGENASE GENE AND A COMPARISON WITH THE DROSOPHILA-MELANOGASTER GENE

The complete glycerol-3-phosphate dehydrogenase gene of Drosophila virilis isolated by screening with alpha-GPDH(M) cDNA of the adult fly was sequenced. The gene contains eight exons spread over a total of approximate 8 kb DNA. Its exon/intron organization is identical to that of D. melanogaster. A single transcription initiation site was determined by primer extension. The stop codons are located at the 3' end of each of the exons 6 to 8. TATA and CAAT boxes are present upstream of the transcriptional start site. Adult alpha-GPDH protein is encoded by exons 1 to 6 and exon 8. Comparison of the sequence with that of D. melanogaster showed that the homology of the nucleotide sequence of the coding region is 85% and that the homology of the amino acid sequence is 98%. On the contrary, the non-coding region is quite different in length and nucleotide sequence.