Cis-regulatory elements in the Accord retrotransposon result in tissue-specific expression of the Drosophila melanogaster insecticide resistance gene Cyp6g1.
Transposable elements are a major mutation source and powerful agents of adaptive change. Some transposable element insertions in genomes increase to a high frequency because of the selective advantage the mutant phenotype provides. Cyp6g1-mediated insecticide resistance in Drosophila melanogaster is due to the upregulation of the cytochrome P450 gene Cyp6g1, leading to the resistance to a variety of insecticide classes. The upregulation of Cyp6g1 is correlated with the presence of the long terminal repeat (LTR) of an Accord retrotransposon inserted 291bp upstream of the Cyp6g1 transcription start site. This resistant allele (DDT-R) is currently at a high frequency in D. melanogaster populations around the world. Here, we characterize the spatial expression of Cyp6g1 in insecticide-resistant and -susceptible strains. We show that the Accord LTR insertion is indeed the resistance-associated mutation and demonstrate that the Accord LTR carries regulatory sequences that increase the expression of Cyp6g1 in tissues important for detoxification, the midgut, Malpighian tubules, and the fat body. This study provides a significant example of how changes in tissue-specific gene expression caused by transposable-element insertions can contribute to adaptation.
Chung
Henry
H
Centre for Environmental and Stress Adaptation Research, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia.
Bogwitz
Michael R
MR
McCart
Caroline
C
Andrianopoulos
Alex
A
Ffrench-Constant
Richard H
RH
Batterham
Philip
P
Daborn
Phillip J
PJ
D000220:Adaptation, Biological / Q000235:genetics*; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers; D004064:Digestive System / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005216:Fat Body / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics*; D017403:In Situ Hybridization; D007305:Insecticide Resistance / Q000235:genetics*; D007814:Larva / Q000378:metabolism; D008317:Malpighian Tubules / Q000378:metabolism; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D018626:Retroelements / Q000235:genetics*; D020079:Terminal Repeat Sequences / Q000235:genetics
D017931:DNA Primers; D029721:Drosophila Proteins; D018626:Retroelements; D003577:Cytochrome P-450 Enzyme System; C446928:Cyp6g1 protein, Drosophila