Incidence of insecticide resistance alleles in sexually-reproducing populations of the peach–potato aphid Myzus persicae (Hemiptera: Aphididae) from southern France

AbstractIntensive chemical treatments have led to the development of a number of insecticide resistance mechanisms in the peach–potato aphid Myzus persicae (Sulzer). Some of these mechanisms are known to be associated with negative pleiotropic effects (resistance costs). Molecular and biochemical methods were used to determine the genotypes or phenotypes associated with four insecticide resistance mechanisms in single aphids from sexually-reproducing populations in southern France. The mechanisms considered were E4 and FE4 carboxylesterase overproduction, modified acetycholinesterase, and kdr and rdl resistance-associated mutations. A new method for determining individual kdr genotypes is presented. Almost all resistant individuals overproduced FE4 carboxylesterase, whereas modified acetylcholinesterase was rare. Both the kdr and rdl resistance mutations were present at high frequencies in French sexually-reproducing populations. The frequencies of insecticide resistance genes were compared before and after sexual reproduction in one peach orchard at Avignon to evaluate the potential impact of selection on the persistence of resistance alleles in the over-wintering phase. The frequencies of the kdr and rdl mutations varied significantly between autumn and spring sampling periods. The frequency of the kdr mutation increased, probably due to pyrethroid treatments at the end of the winter. Conversely, the frequency of the rdl mutation decreased significantly during winter, probably because of a fitness cost associated with this mutation.

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The properties of a carboxylesterase from the peach-potato aphid, Myzus persicae (Sulz.), and its role in conferring insecticide resistance

Biochemical Journal ◽

10.1042/bj1670675 ◽

1977 ◽

Vol 167 (3) ◽

pp. 675-683 ◽

Cited By ~ 135

Author(s):

Alan L. Devonshire

Keyword(s):

Insecticide Resistance ◽

Myzus Persicae ◽

Order Rate Constant ◽

Preliminary Evidence ◽

Exchange Chromatography ◽

Potato Aphid ◽

First Order ◽

Different Strains ◽

Hydrolysis Of ◽

Peach Potato Aphid

Carboxylesterases from different strains of Myzus persicae were examined to try to understand their contribution to insecticide resistance. Preliminary evidence that they are involved comes from the good correlation between the degree of resistance and the carboxylesterase and paraoxon-degrading activity in aphid homogenates. Furthermore the carboxylesterase associated with resistance could not be separated from the insecticide-degrading enzyme by electrophoresis or ion-exchange chromatography. Homogenates of resistant aphids hydrolysed paraoxon 60 times faster than did those of susceptible aphids, yet the purified enzymes from both sources had identical catalytic-centre activities towards this substrate and also towards naphth-1-yl acetate, the latter being hydrolysed by both 2×106 times faster than paraoxon. These observations provide evidence that the enzyme from both sources is identical, and that one enzyme hydrolyses both substrates. This was confirmed by relating the rate of paraoxon hydrolysis to the rate at which paraoxon-inhibited carboxylesterase re-activated. Both had the same first-order rate constant (0.01min−1), showing clearly that the hydrolysis of both substrates is brought about by the same enzyme. Its Km for naphth-1-yl acetate was 0.131mm, and for paraoxon 75pm. The latter very small value could not be measured directly, but was calculated from substrate-competition studies coupled with measurements of re-activation of the diethyl phosphorylated enzyme. Since the purified enzymes from resistant and susceptible aphids had the same catalytic-centre activity, the 60-fold difference between strains must be caused by different amounts of the same enzyme resulting from mutations of the regulator gene(s) rather than of the structural gene.

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A1-3 chromosomal translocations in Italian populations of the peach potato aphid Myzus persicae (Sulzer) not linked to esterase-based insecticide resistance

Bulletin of Entomological Research ◽

10.1017/s0007485312000685 ◽

2013 ◽

Vol 103 (3) ◽

pp. 278-285 ◽

Cited By ~ 7

Author(s):

Marco Rivi ◽

Valentina Monti ◽

Emanuele Mazzoni ◽

Stefano Cassanelli ◽

Michela Panini ◽

...

Keyword(s):

Insecticide Resistance ◽

Myzus Persicae ◽

Chromosomal Rearrangements ◽

Molecular Data ◽

Chromosomal Translocations ◽

Potato Aphid ◽

Mediterranean Regions ◽

The Mediterranean ◽

First Time ◽

Peach Potato Aphid

AbstractEsterase-based resistance in the peach-potato aphid, Myzus persicae (Sulzer), is generally due to one of two alternative amplified carboxylesterase genes, E4 or FE4 (fast E4). The E4 amplified form is distributed worldwide and it is correlated with a particular translocation between autosomes 1 and 3, whereas the FE4 form, which has hitherto not been found to be associated with chromosomal rearrangements, is typical of the Mediterranean regions. In this study, we present for the first time cytogenetic and molecular data on some M. persicae parthenogenetic lineages, which clearly show a chromosomal A1-3 translocation associated with esterase FE4 genes and unrelated to high levels of esterase-based resistance.

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Cloning and analysis of the esterase genes conferring insecticide resistance in the peach-potato aphid, Myzus persicae (Sulzer)

Biochemical Journal ◽

10.1042/bj2940569 ◽

1993 ◽

Vol 294 (2) ◽

pp. 569-574 ◽

Cited By ~ 73

Author(s):

L M Field ◽

M S Williamson ◽

G D Moores ◽

A L Devonshire

Keyword(s):

Insecticide Resistance ◽

Dna Sequences ◽

Myzus Persicae ◽

Amino Acid Sequences ◽

In Vitro Translation ◽

Cdna Clones ◽

Nucleotide Substitutions ◽

Single Nucleotide ◽

Potato Aphid ◽

Peach Potato Aphid

Full-length cDNA clones encoding the esterases (E4 and FE4) that confer insecticide resistance in the peach-potato aphid [Myzus persicae (Sulzer)] were isolated and characterized. The E4 cDNA contained an open reading frame of 1656 nucleotides, coding for a protein of 552 amino acids. The FE4 cDNA shared 99% identity with E4 over this region, the most important difference being a single nucleotide substitution resulting in the FE4 mRNA having an extra 36 nucleotides at the 3′ end. The derived amino acid sequences for the N-terminus of E4 and FE4 were identical, with the first 23 residues being characteristic of a signal peptide and the next 40 residues being an exact match to the N-terminal sequence determined by Edman degradation of both purified proteins. The predicted molecular masses of 58.8 and 60.2 kDa for the E4 and FE4 polypeptides were consistent with those previously observed by in vitro translation of mRNA. Five potential N-linked glycosylation sites were present in both polypeptides, in accordance with earlier evidence that the native esterases are glycoproteins. Comparison of the aphid esterase protein sequences with other serine hydrolases provided evidence that their activity involves a charge-relay system with a catalytic triad the same as that found in acetylcholinesterase. Restriction mapping and sequencing of cloned genomic DNA showed that the E4 gene is spread over 4.3 kb with six introns and that the previously reported differences between the 3′ ends of the E4 and FE4 genes result from single nucleotide substitutions and not gross differences in the DNA sequences.

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