title: Characterisation of Dermanyssus gallinae glutathione S-transferases and their potential as acaricide detoxification proteins.
abstract: BACKGROUND
  Glutathione S-transferases (GSTs) facilitate detoxification of drugs by catalysing the conjugation of the reduced glutathione (GSH) to electrophilic xenobiotic substrates and therefore have a function in multi-drug resistance. As a result, knowledge of GSTs can inform both drug resistance in, and novel interventions for, the control of endo- and ectoparasite species. Acaricide resistance and the need for novel control methods are both pressing needs for Dermanyssus gallinae, a highly economically important haematophagous ectoparasite of poultry.
  
  
  METHODS
  A transcriptomic database representing D. gallinae was examined and 11 contig sequences were identified with GST BlastX identities. The transcripts represented by 3 contigs, designated Deg-GST-1, -2 and -3, were fully sequenced and further characterized by phylogenetic analysis. Recombinant versions of Deg-GST-1, -2 and -3 (rDeg-GST) were enzymically active and acaricide-binding properties of the rDeg-GSTs were established by evaluating the ability of selected acaricides to inhibit the enzymatic activity of rDeg-GSTs.
  
  
  RESULTS
  6 of the identified GSTs belonged to the mu class, followed by 3 kappa, 1 omega and 1 delta class molecules. Deg-GST-1 and -3 clearly partitioned with orthologous mu class GSTs and Deg-GST-2 partitioned with delta class GSTs. Phoxim, permethrin and abamectin significantly inhibited rDeg-GST-1 activity by 56, 35 and 17% respectively. Phoxim also inhibited rDeg-2-GST (14.8%) and rDeg-GST-3 (20.6%) activities.
  
  
  CONCLUSIONS
  Deg-GSTs may have important roles in the detoxification of pesticides and, with the increased occurrence of acaricide resistance in this species worldwide, Deg-GSTs are attractive targets for novel interventions.
authors.affiliation: Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK. Kathryn.Bartley@moredun.ac.uk.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Bartley
authors.affiliation: Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK. Harry.Wright@moredun.ac.uk.
authors.forename: Harry W
authors.initials: HW
authors.lastname: Wright
authors.affiliation: Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK. Robert.Bull@cbre.com.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Bull
authors.affiliation: Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK. John.Huntley@moredun.ac.uk.
authors.forename: John F
authors.initials: JF
authors.lastname: Huntley
authors.affiliation: Moredun Research Institute, International Research Centre, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, EH26 0PZ, UK. Alasdair.Nisbet@moredun.ac.uk.
authors.forename: Alasdair J
authors.initials: AJ
authors.lastname: Nisbet
mesh_terms: D056810:Acaricides / Q000378:metabolism / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D016208:Databases, Factual; D004351:Drug Resistance; D015971:Gene Expression Regulation, Enzymologic; D005982:Glutathione Transferase / Q000145:classification / Q000378:metabolism*; D008925:Mites / Q000187:drug effects* / Q000201:enzymology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D059467:Transcriptome
chemical_list: D056810:Acaricides; D005982:Glutathione Transferase