Genomic clones encoding the Drosophila aldolase gene were isolated and the organization of the gene was determined. The protein-coding region spanning nearly 3.5 kb consists of five coding exons (exon 2, 3, 4α4β, and Aγ). The insect exon 2 corresponds to exons 2 to 7 of vertebrate aldolase genes and thus appears to have been formed by the fusion of these 6 exons into a single exon daring evolution. The Drosophila aldolase gene is predicted to generate mRNAs for three isozymes (α-, β-, and γ-types) from the primary transcripts by alternative usage of the final three exons. The reverse transcriptase-PCR assay revealed the occurrence of mRNAs for the three isozymic forms at different developmental stages, and tissue-specific expression was also found to occur in adult flies. In addition to the usual type mRNA species for the α-, β-, and γ-isozymes, two novel forms of mRNAs, αbeta;- and βγ-type mRNAs, were detected tissue-specifically in adult files, although their functions are unpredictable. The αβ-mRNA is an α-type mRNA in which exon 4β remains unspliced, while the βγ-mRNA is a β-type. mRNA with the exon 4γ remaining unspliced. Recombinant enzymes expressed in Escherichia coli were all active and exhibited different enzymatic properties.
|Number of pages||12|
|Journal||Journal of biochemistry|
|Publication status||Published - Nov 1992|
All Science Journal Classification (ASJC) codes
- Molecular Biology