Applied Entomology and Zoology (2008) 43, 127-133

Satoshi Toda, Shinkichi Komazaki, Hiroki Izawa, Ken Nakada, Shuji Kanazaki, Eiichirou Souda and Tomoko Shigehara (2008)
Development of molecular diagnostics of the two point mutations in acetylcholinesterase gene associated with insecticide resistance in the cotton aphid, Aphis gossypii Glover, (Homoptera: Aphididae) and a survey of genotypic frequency in field populations
Applied Entomology and Zoology 43 (1), 127-133
Abstract: In a previous study, we found two amino acid substitutions, Ser431Phe and Ala302Ser, in the Drosophila Ace paralogous acetylcholinesterase (AP-AChE) genes from pirimicarb-resistant Aphis gossypii. Ser431Phe is responsible for the development of pirimicarb resistance and Ala302Ser may play a role in insensitivity to organophosphorus insecticides. In this study, we developed the two types of molecular diagnostics for detecting these mutations. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based method was developed to detect the Ser431Phe and Ala302Ser mutations. A PCR amplification of specific alleles (PASA) method, designated to detect Ser431Phe mutations allowed the three genotypes to be discriminated more rapidly and simply than by PCR-RFLP. Genotyping of samples collected from Japanese pear and Satsuma mandarin orchards in Japan was carried out using PCR-RFLP. We revealed that the genetic composition of the A. gossypii orchard population changes with time without exposure to insecticide and that molecular diagnostics are useful for monitoring the development of insecticide resistance. Although both mutations were frequently detected in field populations, pirimicarb-resistant aphids did not seem to always constitute a large proportion in field populations in Japan. We found several individuals which had Ser302 without Phe431. This finding denies the concept that this genotype is inviable from the viewpoint of enzymatic kinetics.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Shinkichi Komazaki, T. Shigehara

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis gossypii	Citrus (genus)	Japan
	Aphis gossypii	Pear (Pyrus)	Japan