Acetylcholine receptor subunit genes from Ancylostoma caninum: Altered transcription patterns associated with pyrantel resistance
Acetylcholine receptor subunit genes from Ancylostoma caninum: Altered transcription patterns associated with pyrantel resistance
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DOI：
10.1016/j.ijpara.2008.08.005
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发表时间：
2009-03-01
影响因子：
4
通讯作者：
Kotze, Andrew C.
中科院分区：
文献类型：
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作者：
Kopp, Steven R.;Coleman, Glen T.;Kotze, Andrew C.
具有医学和兽医意义的线虫对烟碱激动剂驱虫药（例如噻嘧啶和左旋咪唑）的耐药性分子机制尚不清楚。犬钩虫（Ancylostoma caninum）的噻嘧啶抗性分离株的鉴定，为在分子水平上探索作为人类钩虫模型的物种的胆碱能抗性机制提供了机会。在这里，我们描述了与秀丽隐杆线虫（UNC-29，UNC-29， -38，-63）。还通过定量 PCR 对这些基因以及另外三个烟碱乙酰胆碱受体亚基基因进行了 mRNA 水平分析，这些基因被认为不是噻嘧啶敏感受体的组成部分，并获得了其部分序列。对两种犬曲霉分离株的基因序列和 mRNA 水平进行了比较，显示出对噻嘧啶的高水平或低水平抗性（如之前的体内功效和体外比较研究所示）。虽然在两个犬放线菌分离株之间没有观察到可能有意义的多态性，但转录定量分析显示，与低水平耐药分离株相比，高度噻嘧啶耐药分离株中三个推定的噻嘧啶受体亚基（AAR-29、-38 和 -63）的水平显着降低。相比之下，被认为不构成噻嘧啶受体的三个亚基（AAR-8、-15和-19）的转录在两个分离株之间没有显着差异，或者在高抗性分离株中略高。该数据表明，编码形成噻嘧啶敏感受体的烟碱乙酰胆碱受体亚基的mRNA转录减少可能是犬放线菌中噻嘧啶抗性机制的一个组成部分。 (C) 2008 年澳大利亚寄生虫学协会。由 Elsevier Ltd 出版。保留所有权利。
The molecular mechanism of resistance to nicotinic agonist anthelmintics such as pyrantel and levamisole in nematodes of medical and veterinary significance is poorly understood. The identification of pyrantel-resistant isolates of the canine hookworm, Ancylostoma caninum, provides an opportunity to explore, at a molecular level, the mechanism of cholinergic resistance in a species that is a model for the human hookworms, Here we describe the cloning of three A. caninum genes orthologous to components of the pyrantel-sensitive nicotinic acetylcholine receptor in Caenorhabditis elegans (UNC-29, -38, -63). Analysis of mRNA levels by quantitative PCR was also performed on these genes, plus an additional three nicotinic acetylcholine receptor subunit genes thought not to be constituents of the pyrantel-sensitive receptor, for which a partial sequence was obtained. Gene sequences and mRNA levels were compared between two isolates of A. caninum showing either high- or low-level resistance to pyrantel (as shown previously by in vivo efficacy and in vitro comparative studies). While no polymorphisms of likely significance between the two A. caninum isolates were observed, quantitative analysis of transcription revealed significantly lower levels for the three putative pyrantel receptor subunits (AAR-29, -38 and -63) in the highly pyrantel-resistant isolate compared with the isolate with low-level resistance. In contrast, transcription of the three subunits thought not to constitute the pyrantel receptor (AAR-8, -15 and -19) was either not significantly different between the two isolates, or slightly higher in the highly-resistant isolate. This data suggests that reduced transcription of the mRNA coding for nicotinic acetylcholine receptor Subunits that form the pyrantel-sensitive receptors may be a component of the pyrantel resistance mechanism in A. caninum. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.