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

Abstract

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.

Comparative analyses of simple sequence repeats (SSRs) in 23 mosquito species genomes: Identification, characterization and distribution (Diptera: Culicidae)

“…With the increasing of mosquito omics data, the diversity, characterization and functional analyses of a given group of genes are progressively increasing (He et al ., ; Liu et al ., ; Mei et al ., ; Wang et al ., ; Wu et al ., ; Yan et al ., ). However, the in silico SSR identification and analysis are relatively insufficient, and therefore the SSR features and the association with different species of mosquito genomes are still not well understood.…”

“…albopictus (Chen et al, 2015) have been sequenced and annotated, and more recently 16 Anopheles genomes have been reported (Neafsey et al, 2015). A number of transcriptomes and mitochondrial genomes have also been sequenced and comparatively analyzed (e.g., Chen et al, 2014;Hua et al, 2016;Hao et al, 2017;Fang et al, 2018) With the increasing of mosquito omics data, the diversity, characterization and functional analyses of a given group of genes are progressively increasing (He et al, 2016;Liu et al, 2018;Mei et al, 2018;Wang et al, 2018;Wu et al, 2018;Yan et al, 2018). However, the in silico SSR identification and analysis are relatively insufficient, and therefore the SSR features and the association with different species of mosquito genomes are still not well understood.…”

Complete mitogenome of Anopheles sinensis and mitochondrial insertion segments in the nuclear genomes of 19 mosquito species

“…An . sinensis is being used as a model species to study the molecular mechanism of insecticide resistance [ 10 – 11 ]. To elucidate the function of the mt genome in insecticide resistance, the mt genome need to be completely sequenced and annotated with a laboratory strain originally collected from Jiangsu, China.…”

Mitochondrial genes associated with pyrethroid resistance revealed by mitochondrial genome and transcriptome analyses in the malaria vector Anopheles sinensis (Diptera: Culicidae)

“…In China, pyrethroids are widely used for medical and agricultural pest control, and high levels of resistance to pyrethroids have been reported in An. sinensis populations in China . The evolution of pyrethroid resistance occurs through complicated mechanisms typically involving interactions between multiple categories of gene .…”