Purification, expression and partial characterization of glutathione s-transferases (GSTs) from three different strains of Aedes albopictus (Diptera: Culicidae).

Glutathione S-transferases (GSTs) are multifunctional enzymes involved in detoxification of xenobiotic compounds in many insect groups. This work investigated the expression of GSTs in Aedes albopictus by using affinity chromatography and proteomic analysis. The study compared the expression of GSTS isoforms in larvae of three Ae. albopictus strains (susceptible (VCRU) strain, field Kuala Lumpur (KL) strain and laboratory permethrintreated strain). The study demonstrated that the expression of sixteen isoforms (GSTS1-1, GSTS1-4, GSTS1-3, GSTS1-4, GSTD1-3, GSTD1-2, GSTD1-5, GSTD1-6, GSTD1-7, GSTD1-8, GSTD1-9, GSTD1-10, GSTD1-11, GSTT, GSTD1-12, and GSTD1-13) were significantly increased in the field KL strain (p<0.05) compared to the susceptible VCRU strain. GSTD1-1, GSTD1-2 and GSTS1-5 showed no significant difference in expression between the two strains (p>0.05). However, while comparing the expression of GST isoforms in field KL larvae and laboratory permethrin-treated strain, the same pattern was observed for all the GSTs especially for Theta and Sigma class (p>0.05). In Delta class, only GSTD1-1, GSTD1-9, GSTD1-11, GSTD1- 12 and GSTD1-13 shows significant difference in expression between these two strain (p<0.05). This comparative data on GST expression in Ae. albopictus can be useful database to identify possible underlying mechanisms governing insecticide resistance by GSTs.