title: Multiple glutathione S-transferase genes: identification and expression in oriental fruit fly, Bactrocera dorsalis.
abstract: BACKGROUND
  The oriental fruit fly, Bactrocera dorsalis (Hendel), is widely distributed in Asia-Pacific regions, where it is a serious pest of a wide range of tropical and subtropical fruit and vegetable crops. In this study, 17 cDNA encoding glutathione S-transferases (GSTs) in B. dorsalis were sequenced and characterised.
  
  
  RESULTS
  Phylogenetic analysis revealed that 16 GSTs belonged to five different cytosolic classes, including four in delta, eight in epsilon, two in omega, one in theta, and one in zeta. The remaining GST (BdGSTu1) was unclassified. RT-qPCR assay showed that the relative expression levels of five GST genes were significantly higher in larval stages than in adulthood. Tissue-specific expression analysis found that BdGSTe3, BdGSTe9 and BdGSTd5 were expressed highly in the midgut, BdGSTe4, BdGSTe6, BdGSTd6 and BdGSTz2 were higher in the fat body, and six GSTs were higher in Malpighian tubules. RT-qPCR confirmed that the expressions of nine GST genes were increased by malathion exposure at various times and doses, while BdGSTe4, BdGSTe9 and BdGSTt1 were increased by β-cypermethrin exposure.
  
  
  CONCLUSIONS
  The increases in GST gene expression levels after malathion and β-cypermethrin exposure in B. dorsalis might increase the ability of this species to detoxify other insecticides and xenobiotics.
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing, 400715, P. R. China; School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, 230009, P. R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Dou
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Wang
authors.forename: Fu-Xian
authors.initials: FX
authors.lastname: Jia
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000818:Animals; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics*; D008294:Malathion / Q000633:toxicity; D009928:Organ Specificity; D033621:Tephritidae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
chemical_list: D005982:Glutathione Transferase; D008294:Malathion
keywords: GSTs; expression; insecticides; oriental fruit fly; resistance; sequences