Contribution of Ldace1 gene to acetylcholinesterase activity in Colorado potato beetle.

Insect Biochem Mol Biol

Dpto. de Biología Medioambiental, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.

Published: October 2011

AI Article Synopsis

  • The Colorado potato beetle (CPB) is a major pest affecting potato crops globally, with resistance to specific insecticides linked to mutations in the acetylcholinesterase (AChE) gene Ldace2.
  • Cloning and sequencing revealed Ldace1, another AChE gene in CPB, which is expressed more abundantly than Ldace2 and plays a crucial role in enzyme activity.
  • Interfering with Ldace1 significantly increased CPB mortality and affected their susceptibility to the insecticide chlorpyrifos, suggesting that future studies should reconsider the links between CPB resistance and mutations in Ldace2.

Article 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.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ibmb.2011.06.001DOI Listing

Publication Analysis

Top Keywords

interference ldace1
12
ache activity
12
ldace1 gene
8
colorado potato
8
potato beetle
8
ldace1
8
activity approximate
8
compared control
8
interference ldace2
8
caused increase
8

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!