Joint first authors.
Developmental expression and gene/enzyme identifications in the alpha esterase gene cluster of Drosophila melanogaster
Article first published online: 15 SEP 2003
Insect Molecular Biology
Volume 12, Issue 5, pages 459–471, October 2003
How to Cite
Campbell, P. M., De Q. Robin, G. C., Court, L. N., Dorrian, S. J., Russell, R. J. and Oakeshott, J. G. (2003), Developmental expression and gene/enzyme identifications in the alpha esterase gene cluster of Drosophila melanogaster. Insect Molecular Biology, 12: 459–471. doi: 10.1046/j.1365-2583.2003.00430.x
- Issue published online: 15 SEP 2003
- Article first published online: 15 SEP 2003
- Received 3 March 2003; accepted after revision 15 May 2003.
- insecticide resistance
Here we show how the 10 genes of the alpha esterase cluster of Drosophila melanogaster have diverged substantially in their expression profiles. Together with previously described sequence divergence this suggests substantial functional diversification. By peptide mass fingerprinting and in vitro gene expression we have also shown that two of the genes encode the isozymes EST9 (formerly ESTC) and EST23. EST9 is the major ‘alpha staining’ esterase in zymograms of gut tissues in feeding stages while orthologues of EST23 confer resistance to organophosphorus insecticides in other higher Diptera. The results for EST9 and EST23 concur with previous suggestions that the products of the alpha esterase cluster function in digestion and detoxification of xenobiotic esters. However, many of the other genes in the cluster show developmental or tissue-specific expression that seems inconsistent with such roles. Furthermore, there is generally poor correspondence between the mRNA expression patterns of the remaining eight genes and isozymes previously characterized by standard techniques of electrophoresis and staining, suggesting that the alpha cluster might only account for a small minority of the esterase isozyme profile.