Detection of single-base substitution in an esterase gene and its linkage to malathion resistance in the parasitoidAnisopteromalus calandrae(Hymenoptera: Pteromalidae)

Abstract

Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae) is an important parasitoid of stored‐grain insect pests. Partial cDNA sequences of an esterase‐like enzyme have been obtained from a malathion‐resistant (R) strain and a susceptible (S) strain of this wasp. A single‐base substitution in the R strain has been confirmed by using PCR amplification of specific allele (PASA) to amplify genomic DNA extracted from individual resistant and susceptible parents, F1 hybrids from double reciprocal crosses, and progeny from backcrosses. The R allele appeared to be inherited in a strict Mendelian fashion in both diploid female and haploid male progeny. The esterase fragment co‐segregated with resistance in these crosses and backcrosses. Female wasps in a mixed population of A calandrae that survived a malathion screen carried the R allele for the esterase‐like enzyme, while those wasps that died did not have the R allele. The single base‐pair mutation, guanine in the R strain and thymine in the S strain, presumably results in a tryptophan‐to‐glycine amino acid substitution in the encoded protein. We do not know how these amino acid substitutions may relate to functional differences in the enzyme. However, this esterase gene or another linked esterase gene may encode the resistance‐associated malathion detoxifying activity in the R strain. © 1999 Society of Chemical Industry

Furanocoumarins and their detoxification in a tri-trophic interaction

“…Most research on parasitoid resistance to toxins has involved insecticides (e.g., Keeratikasikorn & Hooper 1981;Spollen et al 1995;Zhu et al 1999;Willrich & Boethel 2001;Xu et al 2001;Liu et al 2003); in only a small number of these studies has pesticide resistance been linked to rates of metabolic detoxification by parasitoids (e.g., Perez-Mendoza et al 2000;Wu et al 2004;Wu & Miyata 2005). Even fewer studies have examined the effects of hostplant toxins on parasitoids.…”

Two single mutations commonly cause qualitative change of nonspecific carboxylesterases in insects

“…The results from this study support the later hypothesis. The results are consistent with the observation that species other than dipterans also show that mutation at 271 equivalent position in a carboxylesterase from A. calandrea confers OP resistance (Zhu et al, 1999).…”

“…Another variant, W251L (denoted as W271L in this paper), was observed in malathion-resistant populations of L. cuprina and the mutation is known to decrease naphthyl acetate hydrolysis activity and increase activity towards OPs (Campbell et al, 1998). A change at position 251 was also found in a malathion-resistant strain of the parasitoid wasp Anisopteromalus calandrae, but with a different substitution, W251G (Zhu et al, 1999). Although these mutations have not been found in OP-resistant natural populations of the mosquito C. pipiens and the fruitfly D. melanogaster, mutagenesis in vitro proved that their mutant esterases, at least W251L, also showed a change in enzymatic properties similar to their counterparts in L. cuprina (Devonshire et al, 2003;Cui et al, 2007).…”

Gene identification and proteomic analysis of the esterases of the cotton bollworm, Helicoverpa armigera

“…The first involves the substitution of a single amino acid at one of two positions within the active site that enhances the enzyme's ability to hydrolyse OPs to less toxic products (Newcomb et al, 1997;Campbell et al, 1998). This mechanism has been shown in four higher dipterans and one hymenopteran, all proving to possess essentially equivalent substitutions in the active site of the enzymes Claudianos et al, 1999;Zhu et al, 1999;de Carvalho et al, 2006;Hartley et al, 2006). The second mechanism involves overexpression of esterases that bind but do not hydrolyse the OPs, effectively sequestering the insecticide away from its target site.…”