Baxter G D, Barker S C
Department of Parasitology, University of Queensland, Brisbane, Australia.
Insect Biochem Mol Biol. 1999 May;29(5):461-7. doi: 10.1016/s0965-1748(99)00023-5.
Octopamine is a biogenic amine neurotransmitter of invertebrates that binds to a G-protein coupled receptor that has seven transmembrane domains. Formamidine pesticides like amitraz are highly specific agonists of the octopamine receptor. Amitraz is used extensively to control the cattle tick, Boophilus microplus, and many other ticks but now there are strains of ticks that are resistant to amitraz. We have isolated a cDNA from the cattle tick, B. microplus, that belongs to the biogenic amine family of receptors. The predicted amino acid sequence from this cDNA is most similar to octopamine receptors from insects. The nucleotide sequence of this gene from amitraz-resistant and amitraz-susceptible cattle ticks was identical. Thus, a point mutation/s did not confer resistance to amitraz in the strains we studied. Alternative explanations for resistance to amitraz in B. microplus are discussed.
章鱼胺是无脊椎动物的一种生物胺神经递质，它与一种具有七个跨膜结构域的G蛋白偶联受体相结合。甲脒类杀虫剂如双甲脒是章鱼胺受体的高度特异性激动剂。双甲脒被广泛用于控制牛蜱（微小牛蜱）和许多其他蜱虫，但现在存在对双甲脒具有抗性的蜱虫品系。我们从牛蜱微小牛蜱中分离出了一个属于生物胺受体家族的cDNA。该cDNA预测的氨基酸序列与昆虫的章鱼胺受体最为相似。来自抗双甲脒和对双甲脒敏感的牛蜱的该基因的核苷酸序列是相同的。因此，在我们研究的品系中，点突变并未赋予对双甲脒的抗性。文中讨论了微小牛蜱对双甲脒产生抗性的其他解释。
