A deficit of detoxification enzymes: pesticide sensitivity and environmental response in the honeybee

The honeybee genome has substantially fewer protein coding genes ( approximately 11 000 genes) than Drosophila melanogaster ( approximately 13 500) and Anopheles gambiae ( approximately 14 000). Some of the most marked differences occur in three superfamilies encoding xenobiotic detoxifying enzymes. Specifically there are only about half as many glutathione-S-transferases (GSTs), cytochrome P450 monooxygenases (P450s) and carboxyl/cholinesterases (CCEs) in the honeybee. This includes 10-fold or greater shortfalls in the numbers of Delta and Epsilon GSTs and CYP4 P450s, members of which clades have been recurrently associated with insecticide resistance in other species. These shortfalls may contribute to the…