scholarly journals Molecular evidence that insecticide resistance in peach-potato aphids (Myzus persicae Sulz.) results from amplification of an esterase gene

1988 ◽  
Vol 251 (1) ◽  
pp. 309-312 ◽  
Author(s):  
L M Field ◽  
A L Devonshire ◽  
B G Forde
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Molecular Basis ◽  
Chromosome Translocation ◽  
Molecular Evidence ◽  
Cdna Clones ◽  
Specific Chromosome ◽  
Related Variant ◽  
Esterase Gene ◽  
Potato Aphids

cDNA clones for the esterase (E4) responsible for broad insecticide resistance in peach-potato aphids (Myzus persicae Sulz.) were isolated and used to study the molecular basis of resistance. Increased esterase synthesis by resistant aphids was found to be associated with amplification of the structural gene for the esterase (E4 or its closely related variant, FE4), the degree of amplification being correlated with the activity of the esterase and the level of resistance. Hybridization of the cDNA clones to genomic Southern blots showed that only some of the esterase-related restriction fragments are amplified. Qualitative differences between restriction patterns in different clones of resistant aphids correlated with the presence or absence of a specific chromosome translocation and with production of E4 or FE4.

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

1993 ◽  
Vol 294 (2) ◽  
pp. 569-574 ◽  
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.

The ups and downs of insecticide resistance in peach-potato aphids (Myzus persicae) in the UK

2000 ◽  
Vol 19 (8-10) ◽  
pp. 873-879 ◽  
Author(s):  
S.P Foster ◽  
I Denholm ◽  
A.L Devonshire
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Potato Aphids ◽  
The Uk

Clonal turnover of MACE-carrying peach-potato aphids (Myzus persicae (Sulzer), Homoptera: Aphididae) colonizing Scotland

2007 ◽  
Vol 98 (2) ◽  
pp. 115-124 ◽  
Author(s):  
L. Kasprowicz ◽  
G. Malloch ◽  
S. Foster ◽  
J. Pickup ◽  
J. Zhan ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Myzus Persicae ◽  
Negative Selection ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
The Other ◽  
Fitness Costs ◽  
Field Samples ◽  
Sexual Recombination ◽  
Potato Aphids

AbstractPeach-potato aphids, Myzus persicae (Sulzer), collected in Scotland in the years 1995 and 2002–2004 were characterized using four microsatellite loci and three insecticide resistance mechanisms. From 868 samples, 14 multilocus genotypes were defined (designated clones A–N). Five of these (denoted A, B, H, M and N) carried modified acetylcholinesterase (MACE) resistance, the most recent resistance mechanism to have evolved in M. persicae. The current paper shows that the continued presence of MACE aphids is due to turnover, as clones A and B were replaced in field samples by clones H, M and N in later seasons. Thus, insecticide-resistant populations in Scotland can be attributed to multiple waves of rapid clone colonisations and not to the continued presence of stable resistant clones or mutation or sexual recombination in local populations. The MACE clones carried varying levels of the other insecticide resistance mechanisms, kdr and esterase. The presence of these mechanisms could alter the clones success in the field depending on insecticide spraying (positive selection) and resistance fitness costs (negative selection).

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

1977 ◽  
Vol 167 (3) ◽  
pp. 675-683 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document