Identification and characterization of mutations in housefly (Musca domestica) acetylcholinesterase involved in insecticide resistance

Abstract

Acetylcholinesterase (AChE) insensitive to organophosphate and carbamate insecticides has been identified as a major resistance mechanism in numerous arthropod species. However, the associated genetic changes have been reported in the AChE genes from only three insect species; their role in conferring insecticide insensitivity has been confirmed, using functional expression, only for those in Drosophila melanogaster. The housefly, Musca domestica, was one of the first insects shown to have this mechanism; here we report the occurrence of five mutations (Val-180 → Leu, Gly-262 → Ala, Gly-262 → Val, Phe-327 → Tyr and Gly-365 → Ala) in the AChE gene of this species that, either singly or in combination, confer different spectra of insecticide resistance. The baculovirus expression of wild-type and mutated housefly AChE proteins has confirmed that the mutations each confer relatively modest levels of insecticide insensitivity except the novel Gly-262 → Val mutation, which results in much stronger resistance (up to 100-fold) to certain compounds. In all cases the effects of mutation combinations are additive. The mutations introduce amino acid substitutions that are larger than the corresponding wild-type residues and are located within the active site of the enzyme, close to the catalytic triad. The likely influence of these substitutions on the accessibility of the different types of inhibitor and the orientation of key catalytic residues are discussed in the light of the three-dimensional structures of the AChE protein from Torpedo californica and D. melanogaster.

A novel acetylcholinesterase gene in mosquitoes codes for the insecticide target and is non–homologous to theacegeneDrosophila

“…In the housefly Musca domestica and the Colorado potato beetle Leptinotarsa decemlineata, the cloned ace genes seem to be involved in resistance, as indicated by the identification of one or several mutations in strains with an insensitive AChE (Zhu et al 1996;Kozaki et al 2001;Walsh et al 2001). However, in several other arthropod species, the cloned ace gene codes for an AChE that is apparently not involved in resistance.…”

“…It is established beyond doubt that resistance in D. melanogaster and M. domestica is caused by mutations at the ace-2 locus Walsh et al 2001). It has been shown for some years that, in Cx.…”

Molecular characterization and inhibition analysis of the acetylcholinesterase gene from the silkworm maggot, Exorista sorbillans

“…The G353A mutation was also found in AChE from the fruit fly (G324A) (7), the house fly (G262A) (8), Lucilia cuprina (G303A) (11), and Plutella xylostella AChE1 (G324A) (12). Initial modeling of these mutations within the Drosophila structure revealed that G324A is located close to the active-site triad at the base of the gorge, with G324A likely to interact with gorge residues, which affects the orientation of the catalytic serine (ser-200 in Torpedo) and possibly plays a role in influencing inhibitor sensitivity (13,14).…”

Status dan Mekanisme Resistensi Biokimia Crocidolomia pavonana (F.) (Lepidoptera: Crambidae) terhadap Insektisida Organofosfat serta Kepekaannya terhadap Insektisida Botani Ekstrak Biji Barringtonia asiatica

“…Resistensi yang berkaitan dengan enzim dapat terjadi dengan terjadinya mutasi pada enzim yang dimaksud sehingga meningkatkan aktivitas katalitik enzim yang bersangkutan (Hemingway et al 2002;Hemingway et al 2004;Walsh et al 2001) dan/atau meningkatnya jumlah enzim yang diekspresikan (Field et al 1999;Fournier et al 1992). Dengan meningkatnya aktivitas total enzim yang bersangkutan, maka konversi senyawasenyawa toksik insektisida menjadi senyawa yang tidak bersifat toksik dapat berlangsung lebih efektif.…”