Selection of Insensitive Acetylcholinesterase as a Resistance Mechanism in &lt;I&gt;Aedes aegypti&lt;/I&gt; (Diptera: Culicidae) from Santiago de Cuba

Pyrethroids are commonly used as mosquito adulticides and evolution of resistance to these compounds is a major threat to public health. 'Knockdown resistance' to pyrethroids (kdr) is frequently caused by nonsynonymous mutations in the voltage-gated sodium channel transmembrane protein (para) that reduce pyrethroid binding. Early detection of kdr is critical to the development of resistance management strategies in mosquitoes including Aedes aegypti, the most prevalent vector of dengue and yellow fever viruses. Brengues et al. described seven novel mutations in hydrophobic segment 6 of domain II of para in Ae. aegypti. Assays on larvae from strains bearing these mutations indicated reduced nerve sensitivity to permethrin inhibition. Two of these occurred in codons Iso1011 and Val1016 in exons 20 and 21 respectively. A transition in the third position of Iso1011 encoded a Met1011 replacement and a transversion in the second position of Val1016 encoded a Gly1016 replacement. We have screened this same region in 1318 mosquitoes in 32 additional strains; 30 from throughout Latin America. While the Gly1016 allele was never detected in Latin America, we found two new mutations in these same codons. A transition in the first position of codon 1011 encodes a Val replacement while a transition in the first position of codon 1016 encodes an Iso replacement. We developed PCR assays for these four mutations that can be read either on an agarose gel or as a melting curve. Selection experiments, one with deltamethrin on a field strain from Santiago de Cuba and another with permethrin on a strain from Isla Mujeres, Mexico rapidly increased the frequency of the Iso1016 allele. Bioassays of F(3) offspring arising from permethrin susceptible Val1016 homozygous parents and permethrin resistant Iso1016 homozygous parents show that Iso1016 segregates as a recessive allele in conferring kdr. Analysis of segregation between alleles at the 1011 and 1016 codons in the F(3) showed a high rate of recombination even though the two codons are only separated by a ~250 bp intron. The tools and information presented provide a means for early detection and characterization of kdr that is critical to the development of strategies for resistance management.

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“…Selection conditions for F 6 temephos are described in (Rodriguez et al. , 2002) and selection of F 14 propoxur appears in Bisset et al. (2006).…”

Section: Methodsmentioning

confidence: 99%

“…Selection conditions for F 12 and F 13 deltamethrin are described in Rodriguez et al (2005). Selection conditions for F 6 temephos are described in (Rodriguez et al, 2002) and selection of F 14 propoxur appears in Bisset et al (2006).…”

Section: Methodsmentioning

confidence: 99%

A mutation in the voltage‐gated sodium channel gene associated with pyrethroid resistance in Latin American Aedes aegypti

Saavedra-Rodríguez

Urdaneta-Marquez

Rajatileka

et al. 2007

Insect Molecular Biology

325

426

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“…Cuban and Venezuelan populations of Ae. aegypti have been well characterized for target-site insensitivity (Bisset et al 2006) and various forms of metabolic resistance (Rodriguez et al 2001(Rodriguez et al , 2002(Rodriguez et al , 2005.…”

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confidence: 99%

Quantitative Trait Loci Mapping of Genome Regions Controlling Permethrin Resistance in the Mosquito Aedes aegypti

et al. 2008

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The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Permethrin is an insecticide used to suppress Ae. aegypti adult populations but metabolic and target site resistance to pyrethroids has evolved in many locations worldwide. Quantitative trait loci (QTL) controlling permethrin survival in Ae. aegypti were mapped in an F 3 advanced intercross line. Parents came from a collection of mosquitoes from Isla Mujeres, México, that had been selected for permethrin resistance for two generations and a reference permethrin-susceptible strain originally from New Orleans. Following a 1-hr permethrin exposure, 439 F 3 adult mosquitoes were phenotyped as knockdown resistant, knocked down/recovered, or dead. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 22 loci with potential antixenobiotic activity including genes encoding cytochrome P450s (CYP), esterases (EST), or glutathione transferases (GST) and at 12 previously mapped loci. Seven antixenobiotic genes mapped to chromosome I, six to chromosome II, and nine to chromosome III. Two QTL of major effect were detected on chromosome III. One corresponds with a SNP previously associated with permethrin resistance in the para sodium channel gene and the second with the CCEunk7o esterase marker. Additional QTL but of relatively minor effect were also found. These included two sex-linked QTL on chromosome I affecting knockdown and recovery and a QTL affecting survival and recovery. On chromosome II, one QTL affecting survival and a second affecting recovery were detected. The patterns confirm that mutations in the para gene cause target-site insensitivity and are the major source of permethrin resistance but that other genes dispersed throughout the genome contribute to recovery and survival of mosquitoes following permethrin exposure.

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“…The results of superexpressed allele gels showed an increase in metabolic mechanisms of some Ae. aegypti, probably pertinent to the reduction of the use of insecticides in drought/ebb periods or resulting from older populations that left few individuals with the highest allele expressions 23 . The increase of esterase in dry periods (Jun /2016) and the highest average values of enzyme expression in Várzea Grande (75±41.36%) may be related to some biological characteristics of mosquitoes, and even their reproductive fitness in face of the disease and environmental pressure with the use of insecticides by public agencies or particularly by people residing near the breeding sites.…”

Section: Discussionmentioning

confidence: 99%

Investigation of isoenzyme a-esterase in Aedes aegypti from two municipalities of Mato Grosso

Butakka¹,

Siqueira²,

Rodrigues³

et al. 2019

Mundo Saúde

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Esterases are groups of enzymes that increase the mechanism of action of insect vectors in their metabolic activity while under environmental pressure. The aim of this study was to analyze the level of �-esterase expression in Aedes aegypti populations in the municipalities of Cuiabá and Várzea Grande, MT as a way to contribute to vector research. Samples were collected through ovitraps in each municipality and allele results were analyzed by factorial ANOVA between months, locations and seasonal phase. The alleles of 385 Ae. aegypti individuals demonstrated the highest expressions during the ebb period, significantly between months (F7,377=6.89; p<0.01) and between sites (F1,383=11.01). Expressed and superexpressed alleles decreased in Mar/2016, during the "peak water" period and resumed from May/2016 to Nov/2016. Regarding the frequency, expressed alleles increased in Várzea Grande, during the flood period with the highest precipitation. There was an increasing tendency of the expressed alleles with precipitation and the frequency values between Oct/2015 (30%±88) and Feb/2016 (89±55%); meanwhile, for the superexpressed alleles, this occurred during the ebb period (42±91%). Várzea Grande specimens reached a higher frequency of expressed alleles (75±41.36%), but there was a reduction of overexpressed alleles in both municipalities (F2,13=12.39; p<0.01). The results obtained in this study indicate that the esterase isoenzyme method was sensitive enough to detect variations in allele frequency in natural Ae. aegypti populations, which implies an increased metabolic activity over the period examined.

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Selection of Insensitive Acetylcholinesterase as a Resistance Mechanism in <I>Aedes aegypti</I> (Diptera: Culicidae) from Santiago de Cuba

Cited by 18 publications

References 17 publications

A mutation in the voltage‐gated sodium channel gene associated with pyrethroid resistance in Latin American Aedes aegypti

A mutation in the voltage‐gated sodium channel gene associated with pyrethroid resistance in Latin American Aedes aegypti

Quantitative Trait Loci Mapping of Genome Regions Controlling Permethrin Resistance in the Mosquito Aedes aegypti

Investigation of isoenzyme a-esterase in Aedes aegypti from two municipalities of Mato Grosso

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