The Secret Of Ddt-resistant Mosquitoes

摘要

Since the introduction of DDT as an insecticide, several strains of mosquito have evolved and developed resistance to the compound. In resistant insects, DNA microarray studies have pinpointed a number of upregulated cytochrome P450 genes. Ting-Lan Chiu etrnal. modeled the catalytic site geometries of two Anopheles gambiae P450s that appear strongly linked to DDT resistance, finding that one, CYP6Z1, seems to have a site geometry well matched to DDT. In vitro metabolic experiments confirmed the modeling results. The authors report that both CYP6Z1 and CYP6Z2 P450s are overexpressed in re-rnsistant mosquitoes collected in West and East Africa, as evidenced by homology models based on sequence alignments with CYP3A4 (the major drug-metabolizing P450 in humans).