Autor(es)Lumjuan Nongkran,Rajatileka Shavanthi,Changsom Donch,Wicheer Jureeporn,Leelapat Posri,Prapanthadara La-aied,Somboon Pradya,Lycett Gareth,Ranson Hilary

ResumoThe Epsilon glutathione transferase (GST) class in the dengue vector Aedes aegypti consists of eight sequentially arranged genes spanning 53,645 bp on super contig 1.291, which maps to chromosome 2. One Epsilon GST, GSTE2, has previously been implicated in conferring resistance to DDT. The amino acid sequence of GSTE2 in an insecticide susceptible and a DDT resistant strain differs at five residues two of which occur in the putative DDT binding site. Characterization of the respective recombinant enzymes revealed that both variants have comparable DDT dehydrochlorinase activity although the isoform from the resistant strain has higher affinity for the insecticide. GSTe2 and two additional Epsilon GST genes, GSTe5 and GSTe7, are expressed at elevated levels in the resistant population and the recombinant homodimer GSTE5-5 also exhibits low levels of DDT dehydrochlorinase activity. Partial silencing of either GSTe7 or GSTe2 by RNA interference resulted in an increased susceptibility to the pyrethroid, deltamethrin suggesting that these GST enzymes may also play a role in resistance to pyrethroid insecticides.

Palavras-ChaveGlutathione transferase; Aedes aegypti; DDT dehydrochlorinase; Permethrin; RNA interference; Insecticide resistance

ImprentaInsect Biochemistry and Molecular Biology, v. 41, n. 3, p. 203-209, 2011

DescritoresAedes aegypti - Molecular Structure ; Aedes aegypti - Pathogenesis ; Aedes aegypti - RNA ; Aedes aegypti - Dengue

Data de Publicação:2011