TY - JOUR
T1 - Accord insertion in the 5' flanking region of CYP6G1 confers nicotine resistance in Drosophila melanogaster
AU - Li, Xianchun
AU - Bai, Sufen
AU - Cass, Bodil N.
N1 - Funding Information:
We are grateful to Dr. Todd Schlenke (Emory University, GA) for providing us with the eight Drosophila strains used in this study. This work was supported partially by China Natural Science Foundation grant 30325028 to XL. BNC was partially supported by the Center for Insect Science and a P.E.O. International Peace Scholarship.
PY - 2012/7/1
Y1 - 2012/7/1
N2 - What has driven the sweep of the Accord retrotransposon insertion allele of CYP6G1 in the natural populations of Drosophila melanogaster is unknown. Previous studies on the DDT selection hypothesis produced conflicting data. To reexamine the DDT selection hypothesis and search for alternative explanations, we conducted a series of correlation and genetic linkage experiments with eight D. melanogaster natural populations collected from California (CM1, CM2, CM3, and CM7) and Africa (AM2, AM3, AM4, AM7). Diagnostic PCR showed that CM1, CM2, CM7, and AM3 have the Accord insertion in the CYP6G1 locus, whereas the other four strains do not. RT-PCR analysis exhibits a 100% correlation between Accord insertion and CYP6G1 overexpression. However, among the four strains with Accord-mediated CYP6G1 overexpression only CM1 and CM7 are resistant to DDT, and the other two strains (CM2 and AM3), like the four Accord-free strains, are susceptible to DDT. By contrast, all the four strains with Accord-mediated CYP6G1 overexpression are resistant to nicotine, a plant allelochemical. Genetic crosses between DDT resistant and susceptible Accord-insertion strains, as well as crosses between Accord-insertion and Accord-free strains demonstrated that Accord insertion and CYP6G1 overexpression are genetically linked to nicotine resistance rather than DDT resistance. These results suggest that naturally-occurring allelochemicals such as nicotine are the initial driving force for the worldwide prevalence of the Accord insertion allele of CYP6G1 in D. melanogaster natural populations.
AB - What has driven the sweep of the Accord retrotransposon insertion allele of CYP6G1 in the natural populations of Drosophila melanogaster is unknown. Previous studies on the DDT selection hypothesis produced conflicting data. To reexamine the DDT selection hypothesis and search for alternative explanations, we conducted a series of correlation and genetic linkage experiments with eight D. melanogaster natural populations collected from California (CM1, CM2, CM3, and CM7) and Africa (AM2, AM3, AM4, AM7). Diagnostic PCR showed that CM1, CM2, CM7, and AM3 have the Accord insertion in the CYP6G1 locus, whereas the other four strains do not. RT-PCR analysis exhibits a 100% correlation between Accord insertion and CYP6G1 overexpression. However, among the four strains with Accord-mediated CYP6G1 overexpression only CM1 and CM7 are resistant to DDT, and the other two strains (CM2 and AM3), like the four Accord-free strains, are susceptible to DDT. By contrast, all the four strains with Accord-mediated CYP6G1 overexpression are resistant to nicotine, a plant allelochemical. Genetic crosses between DDT resistant and susceptible Accord-insertion strains, as well as crosses between Accord-insertion and Accord-free strains demonstrated that Accord insertion and CYP6G1 overexpression are genetically linked to nicotine resistance rather than DDT resistance. These results suggest that naturally-occurring allelochemicals such as nicotine are the initial driving force for the worldwide prevalence of the Accord insertion allele of CYP6G1 in D. melanogaster natural populations.
KW - Allelochemical tolerance
KW - DDT resistance
KW - Linkage analysis
KW - P450
KW - Selective sweep
KW - Transposable element
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U2 - 10.1016/j.gene.2012.04.031
DO - 10.1016/j.gene.2012.04.031
M3 - Article
C2 - 22543020
AN - SCOPUS:84860916064
SN - 0378-1119
VL - 502
SP - 1
EP - 8
JO - Gene
JF - Gene
IS - 1
ER -