Contribution of Ldace1 gene to acetylcholinesterase activity in Colorado potato beetle

Abstract

The Colorado potato beetle (CPB), Leptinotarsa decemlineata is an important economic pest of potato worldwide. Resistance to organophosphates and carbamates in CPB has been associated in some cases to point mutations in the acetylcholinesterase (AChE) gene Ldace2, an orthologue of Drosophila melanogaster Dmace2. In this paper we report cloning and sequencing of Ldace1, an orthologue of Anopheles gambiae Agace1 that was previously unknown in CPB. The Ldace1 coding enzyme contains all residues conserved in a functionally active AChE. Ldace1 is expressed at higher levels (between 2- and 11-fold) than Ldace2 in embryos, in the four larval instars and in adults. Specific interference of Ldace1 by means of dsRNA injection resulted in a reduction of AChE activity to an approximate 50% compared to control, whilst interference of Ldace2 reduced AChE activity to an approximate 85%. Analysis of zymograms of AChE activity after interference indicates that LdAChE1 is the enzyme predominantly responsible for the activity visualised. Interference of Ldace1 in CPB adults caused a significant increase in mortality (43%) as early as three days post-injection (p.i.), suggesting the essential role of Ldace1. Interference of Ldace2 also caused a significant increase in mortality (29%) compared to control, although at seven days p.i. The effect of the interference of Ldace1 on susceptibility to the organophosphate chlorpyrifos points out that LdAChE1 could be a main target for this insecticide. In the light of our results, studies associating resistance in CPB to mutations in Ldace2 should be reviewed, taking into consideration analysis of the Ldace1 gene.

Molecular Characterization and Expression Analysis of Two Acetylcholinesterase Genes From the Small White Butterfly Pieris rapae (Lepidoptera: Pieridae)

“…This is consistent with previous reports of ace genes in the majority of insect species (Kim et al 2006, Lee et al 2006, Revuelta et al 2011, Wang et al 2016a). However, in B. mori , ace2 has a different transcription profile and is expressed more abundantly than ace1 (Chen et al 2009, Ye et al 2017).…”

“…Therefore, these genes have attracted much attention in insecticide toxicological studies (Alizadeh et al 2014, Miao et al 2016, Zhou et al 2016). Recently, it was shown that knockdown of ace1 genes led to increased sensitivity of insects to AChE insecticides (Revuelta et al 2009, 2011, Lu et al 2012b), and that silencing ace1 and/or ace2 impacted insect development (He et al 2012, Lu et al 2012b, Salim et al 2017). This suggests that these genes could be utilized for developing RNAi-based pest control strategies (Kim et al 2015).…”

“…AChE is encoded by the ace gene (Kim and Lee 2018). In the class Insecta, two types of ace genes ( ace1 and ace2 ) have been identified in numerous insect species from various orders, including mosquitoes (Weill et al 2002, 2004), moths (Shang et al 2007, Hui et al 2011), butterflies (Li et al 2015), aphids (Li and Han 2002, Nabeshima et al 2003), planthoppers (Kwon et al 2012, Li et al 2012), honeybees (Kim et al 2012b), beetles (Revuelta et al 2011, Wang et al 2017a), cockroaches (Kim et al 2006, 2010), and bugs (Hwang et al 2014, Liu et al 2017a). However, in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae), the house fly Musca domestica L. (Diptera: Muscidae) , and other fly species in the Cyclorrhapha suborder of Diptera, only a single ace2 gene has been identified (Weill et al 2002, Huchard et al 2006).…”

Population dependent effects of photoperiod on diapause related physiological traits in an invasive beetle (Leptinotarsa decemlineata)

“…Primers used for qPCR were obtained from previously published studies (Yocum et al 2011, Revuelta et al 2011 for L. decemlineata. I also designed primers based on sequences of an annotated transcriptome of the L. decemlineata (Kumar et al in review) and gene sequences available in GenBank for L. decemlineata and Chrysomela tremula using Primer3 (http://frodo.wi.mit.edu/primer3/, v. 0.4.0).…”

Untitled

“…Revista Bio Ciencias 4(6), Article ID 04.06.01 December 2017 presentes en A. gambiae (Weill et al, 2002;Fournier, 2005), sin embargo, en D. melanogaster la AChE es codificada úni-camente por ace2 (Fournier et al, 1993;Weill et al, 2002;Huchard et al, 2006); estudios en otros insectos que poseen ambos genes, sugieren que ace1 es el gen responsable de una mayor actividad de la AChE (Revuelta et al, 2009;Revuelta et al, 2011).…”