Differential Gene Expression Profiles of Cypermethrin-resistant Plutella xylostella (Lepidoptera: Plutellidae)

다국어 초록 (Multilingual Abstract)

To determine differential gene expression profiles in a cypermethrin-resistant strain (CR) of diamondback moth, Plutella xylostella Linnaeus (1758), a subtractive cDNA library was constructed by suppression subtractive hybridization. A total of 1196 expressed sequence tags (EST) were clustered and assembled into 579 contigs (100 multiplets and 479 singletons). About 46% (267) of 579 contigs had the matched BLASTx hits (E ≤ 10-5). Among these, 143 contigs had similarity to proteins with assigned molecular function in the Functional Catalogue database, and most of them (86%) were homologous to the genes from insects, particularly to Lepidoptera (56%). The contigs encoding carboxylesterase and cytochrome P450 known to be involved in the insecticide resistance were found in the library. They were identified as pxest3, pxest4, and CYP9G2 gene by 5' and 3' RACE. Among these, pxest4 was determined to be 2-fold over-transcribed in the CR strain by qrtPCR. Several contigs encoding enzymes including cytochrome oxidase subunit I that are likely involved in the insecticide resistance were also identified from the library. Discovery of the genes specific to cypermethrin resistance should promote further studies on the molecular mechanisms of insecticide resistance in P. xylostella.