Different amino-acid substitutions confer insecticide resistance through acetylcholinesterase 1 insensitivity in Culex vishnui and Culex tritaeniorhynchus (Diptera: Culicidae) from China.
Insecticide resistance owing to insensitive acetylcholinesterase (AChE)1 has been reported in several mosquito species, and only two mutations in the ace-1 gene have been implicated in resistance: 119S and 331W substitutions. We analyzed the AChE1 resistance status of Culex vishnui (Theobald) and Culex tritaeniorhynchus Giles sampled in various regions of China. These two species displayed distinct mutations leading to AChE1 insensitivity; the 119S substitution in resistant C. vishnui mosquitoes and the 331W substitution in resistant C. tritaeniorhynchus. A biochemical test was validated to detect the 331W mutation in field samples. The comparison of the recombinant G119S and 331W mutant proteins produced in vitro with the AChE1 extracted from resistant mosquitoes indicated that the AChE1 insensitivity observed could be specifically attributed to these substitutions. Comparison of their biochemical characteristics indicated that the resistance conferred by these mutations depends on the insecticide used, regardless of its class. This resistance seemed to be fixed in the Cx. tritaeniorhynchus populations sampled in a 2000-km transect, suggesting a very high level of insecticide application or a low fitness cost associated with this 331W mutation.
Alout
Haoues
H
Team Genetics of Adaptation, Laboratoire Génétique et Environnement, Institut des Sciences de l'Evolution (UMR CNRS 5554), Université de Montpellier II (C.C. 065), F-34095 Montpellier, France.
Berthomieu
Arnaud
A
Cui
Feng
F
Tan
Yi
Y
Berticat
Claire
C
Qiao
Chuanling
C
Weill
Mylène
M
D000110:Acetylcholinesterase / Q000235:genetics* / Q000378:metabolism; D019943:Amino Acid Substitution; D000818:Animals; D002681:China; D003465:Culex / Q000187:drug effects* / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology*; D009154:Mutation / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism
D007306:Insecticides; D011994:Recombinant Proteins; D000110:Acetylcholinesterase