Cis-regulatory elements in the Accord retrotransposon result in tissue-specific expression of the Drosophila melanogaster insecticide resistance gene Cyp6g1
Cis-regulatory elements in the Accord retrotransposon result in tissue-specific expression of the Drosophila melanogaster insecticide resistance gene Cyp6g1
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DOI：
10.1534/genetics.106.066597
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发表时间：
2007-03-01
期刊：
影响因子：
3.3
通讯作者：
Daborn, Phillip J.
中科院分区：
文献类型：
--
作者：
Chung, Henry;Bogwitz, Michael R.;Daborn, Phillip J.
转座因子是主要的突变源和适应性变化的强大媒介。由于突变表型提供的选择性优势，基因组中的一些转座元件插入频率增加。果蝇中 Cyp6g1 介导的杀虫剂抗性是由于细胞色素 P450 基因 Cyp6g1 的上调，导致对多种杀虫剂产生抗性。 Cyp6g1 的上调与插入 Cyp6g1 转录起始位点上游 291bp 的 Accord 逆转录转座子的长末端重复序列 (LTR) 的存在相关。这种抗性等位基因 (DDT-R) 目前在世界各地的变腹果蝇种群中出现频率很高。在这里，我们描述了 Cyp6g1 在杀虫剂抗性和敏感菌株中的空间表达。我们证明 Accord LTR 插入确实是与耐药性相关的突变，并证明 Accord LTR 携带调节序列，可增加对解毒重要的组织、中肠、马氏小管和脂肪体中 Cyp6g1 的表达。这项研究提供了一个重要的例子，说明转座元件插入引起的组织特异性基因表达的变化如何有助于适应。
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. metanogaster 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.