A comparative study of P450 gene expression in field and laboratory Musca domestica L. strains.
BACKGROUND
The housefly is a global pest that has developed resistance to most insecticides applied for its control. Resistance has been associated with cytochrome P450 monooxygenases (P450s). The authors compare the expression of six genes possibly associated with insecticide resistance in three unselected strains: a multiresistant strain (791a), a neonicotinoid-resistant strain (766b) and a new field strain (845b).


RESULTS
CYP4G2 was highly expressed throughout the range of strains and proved to be the one of the most interesting expression profiles of all P450s analysed. CYP6G4 was expressed up to 11-fold higher in 766b than in WHO-SRS. Significant differences between expression of P450 genes between F1 flies from 845b and established laboratory strains were shown. In general, P450 gene expression in 845b was 2-14-fold higher than in the reference strain (P < 0.0101) and 2-23-fold higher than in the multiresistant strain (P < 0.0110).


CONCLUSIONS
The newly collected field strain 845b had significantly higher constitutive gene expression than both WHO-SRS and 791a. High constitutive expression of CYP4G2 in houseflies indicates a possible role of this gene in metabolic resistance. There is a strong indication that CYP6G4 is a major insecticide resistance gene involved in neonicotinoid resistance.
Department of Agroecology, Aarhus University, Denmark.
Dorte H
DH
Højland
Karl-Martin
KM
Vagn Jensen
Michael
M
Kristensen
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D003718:Denmark; D015870:Gene Expression / Q000187:drug effects*; D006793:Houseflies / Q000187:drug effects* / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000378:metabolism / Q000633:toxicity
D019476:Insect Proteins; D007306:Insecticides; D003577:Cytochrome P-450 Enzyme System
Musca domestica; cytochrome P450 differential transcription; resistance mechanism; sex-linked expression; spinosad