Identification and classification of detoxification enzymes from Culex quinquefasciatus (Diptera: Culicidae)

Reddy, BP Niranjan; Rao, B. Prasad; Prasad, Gbks; Raghavendra, Kamaraju

doi:10.6026/97320630008430

Cited by 16 publications

(9 citation statements)

References 17 publications

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“…This microarray study also identified that four other detoxification genes (three glutathione S-transferases (GSTs) and one esterase) were also over-transcribed compared to TPRI, although they were not differently expressed between Tororo resistant and sympatric unexposed controls. High expression of these genes alone or in combination with other detoxification enzymes could also be a possible mechanism associated with the bendiocarb phenotype as reported previously 76,77 , although in our data no significant synergist effect by DEM, a GST inhibitor, was observed. Further characterization of these genes is warranted.…”

Section: Discussionsupporting

confidence: 77%

Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vectorCulex quinquefasciatus

Martins

Wilding

Isaacs

et al. 2019

Preprint

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Culex quinquefasciatus plays an important role in transmission of vector-borne diseases of public health importance, including lymphatic filariasis (LF), as well as many arboviral diseases.Currently, efforts to tackle C. quinquefasciatus vectored diseases are based on either mass drug administration (MDA) for LF, or insecticide-based interventions. Widespread and intensive insecticide usage has resulted in increased resistance in mosquito vectors, including C. quinquefasciatus. Herein, the transcriptome profile of Ugandan bendiocarb-resistant C. quinquefasciatus was explored to identify candidate genes associated with insecticide resistance.Resistance to bendiocarb in exposed mosquitoes was marked, with 2.04% mortality following 1h exposure and 58.02% after 4h. Genotyping of the G119S Ace-1 target site mutation detected a highly significant association (p<0.0001; OR=25) between resistance and Ace1-119S. However, synergist assays using the P450 inhibitor PBO or the esterase inhibitor TPP resulted in markedly increased mortality (to ≈ 80%), suggesting a role of metabolic resistance in the resistance phenotype. Using a novel, custom 60K whole-transcriptome microarray 16 genes significantly overexpressed in resistant mosquitoes were detected, with the P450 Cyp6z18 showing the highest differential gene expression (>8-fold increase vs unexposed controls). These results provide evidence that bendiocarb-resistance in Ugandan C. quinquefasciatus is mediated by both targetsite mechanisms and over-expression of detoxification enzymes. 10,11 . Consequently, identification and monitoring of resistance patterns, and understanding the underlying mechanisms is crucial for extending the lifespan of currently available insecticides, as well as for planning more effective vector control programmes.Insensitivity to insecticides in arthropods is thought to result mainly through mutations in target-site genes and/or overproduction of detoxifying enzymes 12,13 . Susceptibility studies in C. quinquefasciatus from diverse geographical regions have associated two main target-site mutations to resistant phenotypes. The L1014F mutation in the voltage-gated sodium channel gene, conferring kdr (knockdown resistance), has been associated with pyrethroid and DDT resistance, whilst the G119S mutation in the acetylcholinesterase (Ace-1) gene is linked to resistance to carbamates and organophosphates [13][14][15][16] . Metabolic resistance, which involves the over-expression, or increased catalytic capability of metabolic enzymes, is a less tractable mechanism since members of diverse gene families including carboxy/cholinesterases, glutathione S-transferases (GSTs) and cytochrome P450 monooxygenases (P450s) have previously been associated with resistance to different classes of insecticide in a range of vector species [17][18][19] . Over-expression of detoxification genes can be triggered by a range of mechanisms including gene duplication 20 , as observed for the resistance to organophosphates in C. quinquefasciatus mediated by esterases 21 , ...

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Section: Discussionsupporting

confidence: 77%

Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vectorCulex quinquefasciatus

Martins

Wilding

Isaacs

et al. 2019

Preprint

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“…Detoxification of synthetic or natural xenobiotics such as an insecticide or plant 86 toxins involves three phases consisting several metabolizing enzymes (Liska, 1998;87 Nakata et al, 2006;Reddy et al, 2012). Phase I mainly consists of the enzymes from 88 cytochrome P450 supergene family, where the P450 enzymes oxidize the parent molecule 89…”

Section: Introduction 49mentioning

confidence: 99%

Transcription factor cap n collar C regulates multiple cytochrome P450 genes conferring adaptation to potato plant allelochemicals and resistance to imidacloprid in Leptinotarsa decemlineata (Say)

Kalsi

Palli

2017

Insect Biochemistry and Molecular Biology

115

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Colorado potato beetle (CPB), Leptinotarsa decemlineata is a notorious pest of potato. Co-evolution with Solanaceae plants containing high levels of toxins (glycoalkaloids) helped this insect to develop an efficient detoxification system and resist almost every chemical insecticide introduced for its control. Even though the cross-resistance between plant allelochemicals and insecticides is well acknowledged, the underlying molecular mechanisms are not understood. Here, we investigated the molecular mechanisms involved in detoxification of potato plant allelochemicals and imidacloprid resistance in the field-collected CPB. Our results showed that the imidacloprid-resistant beetles employ metabolic detoxification of both potato plant allelochemicals and imidacloprid by upregulation of common cytochrome P450 genes. RNAi aided knockdown identified four cytochromes P450 genes (CYP6BJ, CYP6BJ1v1, CYP9Z25, and CYP9Z29) that are required for defense against both natural and synthetic chemicals. These P450 genes are regulated by the xenobiotic transcription factors Cap n Collar C, CncC and muscle aponeurosis fibromatosis, Maf. Studies on the CYP9Z25 promoter using the luciferase reporter assay identified two binding sites (i.e. GCAGAAT and GTACTGA) for CncC and Maf. Overall, these data showed that CPB employs the metabolic resistance mediated through xenobiotic transcription factors CncC and Maf to regulate multiple P450 genes and detoxify both imidacloprid and potato plant allelochemicals.

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“…sinensis , but there was no comparable gene in An. gambiae , Aedes aegypti or Culex quinquefasciatus . There are three genes in D. melanogaster , which represents a contraction of this subfamily in mosquito species.…”

Section: Resultsmentioning

confidence: 99%

Identification of carboxylesterase genes associated with pyrethroid resistance in the malaria vector Anopheles sinensis (Diptera: Culicidae)

et al. 2017

Pest Management Science

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BACKGROUND: Carboxylesterases (CCEs) are one of three large detoxification enzyme families. Some CCEs are active on synthetic insecticides with ester structures. Anopheles sinensis is an important malaria vector in eastern Asia. This study identified and characterized the CCE genes in the A. sinensis genome and determined CCE genes associated with pyrethroid resistance using RNA sequencing (RNA-seq) and quantitative reverse transcription − polymerase chain reaction (qRT-PCR), in A. sinensis from Anhui, Chongqing, and Yunnan in China.RESULTS: Fifty-seven putative CCEs were identified and placed into three classes, 12 subfamilies and 14 clades through phylogenetic and homology analyses. Exon sizes ranged from 31 to 4317 bp, with 49 CCEs having two to five exons and eight having six to 11 exons. A total of 183 introns were recognized with sizes ranging from 31 to 4317 bp. The 57 CCEs were located on 14 scaffolds, with 70% located on four scaffolds. The alpha-esterase subfamily was significantly expanded compared with that of Anopheles gambiae. In a pyrethroid-resistant strain, RNA-seq detected five upregulated CCE genes and qRT-PCR detected 12 upregulated CCE genes. The -esterase 10 (AsAe10) and acetylcholinesterase 1 (AsAce1) genes were the main CCE genes associated with pyrethroid resistance. CONCLUSION: This information will be useful for further study of the CCE gene family and pyrethroid resistance mechanisms mediated by CCEs.

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Identification and classification of detoxification enzymes from Culex quinquefasciatus (Diptera: Culicidae)

Cited by 16 publications

References 17 publications

Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vectorCulex quinquefasciatus

Transcriptomic analysis of insecticide resistance in the lymphatic filariasis vectorCulex quinquefasciatus

Transcription factor cap n collar C regulates multiple cytochrome P450 genes conferring adaptation to potato plant allelochemicals and resistance to imidacloprid in Leptinotarsa decemlineata (Say)

Identification of carboxylesterase genes associated with pyrethroid resistance in the malaria vector Anopheles sinensis (Diptera: Culicidae)

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