Induction of a detoxification gene in Drosophila melanogaster requires an interaction between tissue specific enhancers and a novel cis-regulatory element

Chung, Henry; Boey, Adrian; Lumb, Chris; Willoughby, Lee; Batterham, Philip; Daborn, Phillip J.

doi:10.1016/j.ibmb.2011.07.002

Cited by 15 publications

(19 citation statements)

References 45 publications

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“…The RNAseq data further imply that regulatory, rather than structural variation at these detoxification loci is responsible for a large fraction of the variation in the resistance phenotype. This interpretation is supported by experiments showing that P450 expression can be induced in the presence of xenobiotics in flies (Willoughby et al 2006;Chung et al 2011) and other organisms (Snyder and Glendinning 1996), and by studies demonstrating that lines resistant to insecticides can show higher levels of expression of one or more P450 genes than susceptible lines (for example, Daborn et al 2002). Studies demonstrating that cis-regulatory variation at P450 loci associates with both increased expression levels and heightened insecticide resistance are also consistent with our observations (Dombrowski et al 1998;Daborn et al 2002;Chung et al 2007;Schmidt et al 2010).…”

Section: Discussionsupporting

confidence: 89%

Fine-Mapping Nicotine Resistance Loci inDrosophilaUsing a Multiparent Advanced Generation Inter-Cross Population

et al. 2014

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Animals in nature are frequently challenged by toxic compounds, from those that occur naturally in plants as a defense against herbivory, to pesticides used to protect crops. On exposure to such xenobiotic substances, animals mount a transcriptional response, generating detoxification enzymes and transporters that metabolize and remove the toxin. Genetic variation in this response can lead to variation in the susceptibility of different genotypes to the toxic effects of a given xenobiotic. Here we use Drosophila melanogaster to dissect the genetic basis of larval resistance to nicotine, a common plant defense chemical and widely used addictive drug in humans. We identified quantitative trait loci (QTL) for the trait using the DSPR (Drosophila Synthetic Population Resource), a panel of multiparental advanced intercross lines. Mapped QTL collectively explain 68.4% of the broad-sense heritability for nicotine resistance. The two largest-effect loci-contributing 50.3 and 8.5% to the genetic variation-map to short regions encompassing members of classic detoxification gene families. The largest QTL resides over a cluster of ten UDP-glucuronosyltransferase (UGT) genes, while the next largest QTL harbors a pair of cytochrome P450 genes. Using RNAseq we measured gene expression in a pair of DSPR founders predicted to harbor different alleles at both QTL and showed that Ugt86Dd, Cyp28d1, and Cyp28d2 had significantly higher expression in the founder carrying the allele conferring greater resistance. These genes are very strong candidates to harbor causative, regulatory polymorphisms that explain a large fraction of the genetic variation in larval nicotine resistance in the DSPR.A routine part of life for all organisms is avoiding, and if necessary metabolizing, toxic substances encountered in the environment. A common challenge for animals are those toxins produced by potential prey and plant hosts as chemical defenses against predation and herbivory (Glendinning 2002(Glendinning , 2007. Understanding how organisms overcome these defenses can give us insight into the evolution of host specialization, which can often involve an organism overcoming the defenses of a particular host, avoiding competition by making use of a resource toxic to other species (for example, Hungate et al. 2013). Many animals, especially insects, are also commonly exposed to chemical pesticides used to protect crop plants. As a consequence of this strong evolutionary pressure, there are a number of examples of insecticide resistance arising in natural populations (Crow 1957). Understanding the biology and molecular genetics underlying resistance to insecticides (Perry et al. 2011;Ffrench-Constant 2013) is valuable in the design of pest management strategies. In addition, humans are frequently exposed to an array of potentially harmful compounds, notably pharmaceuticals. Given the desire to achieve maximal drug efficacy while minimizing dosage and avoiding adverse drug responses, elaborating the mechanisms of drug metabolism, and the genet...

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Section: Discussionsupporting

confidence: 89%

Fine-Mapping Nicotine Resistance Loci inDrosophilaUsing a Multiparent Advanced Generation Inter-Cross Population

et al. 2014

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“…Expression in the midgut, Malpighian tubules and fat body is controlled by two distinct tissue-specific enhancers, one that drives expression in the Malpighian tubules and another that drives expression in the midgut and fat body [11], [25]. mRNA for the Cyp6g1 orthologs from all four species was detected in the midgut.…”

Section: Resultsmentioning

confidence: 99%

Evolutionary Changes in Gene Expression, Coding Sequence and Copy-Number at the Cyp6g1 Locus Contribute to Resistance to Multiple Insecticides in Drosophila

et al. 2014

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Widespread use of insecticides has led to insecticide resistance in many populations of insects. In some populations, resistance has evolved to multiple pesticides. In Drosophila melanogaster, resistance to multiple classes of insecticide is due to the overexpression of a single cytochrome P450 gene, Cyp6g1. Overexpression of Cyp6g1 appears to have evolved in parallel in Drosophila simulans, a sibling species of D. melanogaster, where it is also associated with insecticide resistance. However, it is not known whether the ability of the CYP6G1 enzyme to provide resistance to multiple insecticides evolved recently in D. melanogaster or if this function is present in all Drosophila species. Here we show that duplication of the Cyp6g1 gene occurred at least four times during the evolution of different Drosophila species, and the ability of CYP6G1 to confer resistance to multiple insecticides exists in D. melanogaster and D. simulans but not in Drosophila willistoni or Drosophila virilis. In D. virilis, which has multiple copies of Cyp6g1, one copy confers resistance to DDT and another to nitenpyram, suggesting that the divergence of protein sequence between copies subsequent to the duplication affected the activity of the enzyme. All orthologs tested conferred resistance to one or more insecticides, suggesting that CYP6G1 had the capacity to provide resistance to anthropogenic chemicals before they existed. Finally, we show that expression of Cyp6g1 in the Malpighian tubules, which contributes to DDT resistance in D. melanogaster, is specific to the D. melanogaster–D. simulans lineage. Our results suggest that a combination of gene duplication, regulatory changes and protein coding changes has taken place at the Cyp6g1 locus during evolution and this locus may play a role in providing resistance to different environmental toxins in different Drosophila species.

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“…Over-expression correlated with the presence of a single insertion of an Accord transposable element into the 5′ end of the Cyp6g1 gene has also been reported [12]. A recent study of Cyp6g1 induction in transgenic Drosophila showed tissue-specific expression of this gene controlled by two distinct specific enhancers, suggesting that a single mutation event can modulate Cyp6g1 expression [13].…”

Section: Introductionmentioning

confidence: 85%

Use of Mutagenesis, Genetic Mapping and Next Generation Transcriptomics to Investigate Insecticide Resistance Mechanisms

et al. 2012

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Insecticide resistance is a worldwide problem with major impact on agriculture and human health. Understanding the underlying molecular mechanisms is crucial for the management of the phenomenon; however, this information often comes late with respect to the implementation of efficient counter-measures, particularly in the case of metabolism-based resistance mechanisms. We employed a genome-wide insertional mutagenesis screen to Drosophila melanogaster, using a Minos-based construct, and retrieved a line (MiT[w−]3R2) resistant to the neonicotinoid insecticide Imidacloprid. Biochemical and bioassay data indicated that resistance was due to increased P450 detoxification. Deep sequencing transcriptomic analysis revealed substantial over- and under-representation of 357 transcripts in the resistant line, including statistically significant changes in mixed function oxidases, peptidases and cuticular proteins. Three P450 genes (Cyp4p2, Cyp6a2 and Cyp6g1) located on the 2R chromosome, are highly up-regulated in mutant flies compared to susceptible Drosophila. One of them (Cyp6g1) has been already described as a major factor for Imidacloprid resistance, which validated the approach. Elevated expression of the Cyp4p2 was not previously documented in Drosophila lines resistant to neonicotinoids. In silico analysis using the Drosophila reference genome failed to detect transcription binding factors or microRNAs associated with the over-expressed Cyp genes. The resistant line did not contain a Minos insertion in its chromosomes, suggesting a hit-and-run event, i.e. an insertion of the transposable element, followed by an excision which caused the mutation. Genetic mapping placed the resistance locus to the right arm of the second chromosome, within a ∼1 Mb region, where the highly up-regulated Cyp6g1 gene is located. The nature of the unknown mutation that causes resistance is discussed on the basis of these results.

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Induction of a detoxification gene in Drosophila melanogaster requires an interaction between tissue specific enhancers and a novel cis-regulatory element

Cited by 15 publications

References 45 publications

Fine-Mapping Nicotine Resistance Loci inDrosophilaUsing a Multiparent Advanced Generation Inter-Cross Population

Fine-Mapping Nicotine Resistance Loci inDrosophilaUsing a Multiparent Advanced Generation Inter-Cross Population

Evolutionary Changes in Gene Expression, Coding Sequence and Copy-Number at the Cyp6g1 Locus Contribute to Resistance to Multiple Insecticides in Drosophila

Use of Mutagenesis, Genetic Mapping and Next Generation Transcriptomics to Investigate Insecticide Resistance Mechanisms

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