Castella C, Castells-Brooke N, Bergé J B, Pauron D
Institut National de la Recherche Agronomique, Laboratoire de Biologie des Invertébrés, Antibes, France.
Invert Neurosci. 1997 Jun;3(1):41-7. doi: 10.1007/BF02481713.
Knockdown resistance (kdr) to pyrethroid insecticides has been found in numerous insect species. kdr causes nerve insensitivity by altering the primary target of these insecticides, the voltage-sensitive sodium channel. In Musca domestica, cloning and sequencing of susceptible, kdr, and super-kdr alleles of the sodium channel gene (Msc) homologous to the Drosophila melanogaster para channel gene has revealed point mutations. The conservation of the nature and of the position of these mutations strongly suggests a role in the kdr mechanism. To determine if these mutations are associated with modifications of channel expression in adult flies, we investigated the localization of the Msc transcripts, and the size and the tissue distribution of the channel protein in pyrethroid-susceptible and super-kdr strains. Msc channels were mainly found in the cortical regions of the central nervous system with additional labeling in some neuronal processes and in the eyes. No qualitative or quantitative difference was observed between the strains. In immunoblotting experiments, anti-Msc antibodies bound to only one polypeptide of 260 kDa in adult brain. No differences were found in antibody staining between susceptible and pyrethroid-resistant strains. These results were correlated with those on Drosophila melanogaster, for which two sodium channel genes have been identified.
在众多昆虫物种中都发现了对拟除虫菊酯类杀虫剂的击倒抗性（kdr）。kdr通过改变这些杀虫剂的主要靶标——电压敏感钠通道，导致神经不敏感。在家蝇中，与黑腹果蝇para通道基因同源的钠通道基因（Msc）的敏感、kdr和超级kdr等位基因的克隆和测序揭示了点突变。这些突变的性质和位置的保守性强烈表明其在kdr机制中发挥作用。为了确定这些突变是否与成年果蝇中通道表达的改变有关，我们研究了Msc转录本的定位，以及拟除虫菊酯敏感和超级kdr品系中通道蛋白的大小和组织分布。Msc通道主要存在于中枢神经系统的皮质区域，在一些神经突和眼睛中也有额外的标记。在这些品系之间未观察到定性或定量差异。在免疫印迹实验中，抗Msc抗体仅与成年大脑中一条260 kDa的多肽结合。在敏感品系和拟除虫菊酯抗性品系之间，抗体染色未发现差异。这些结果与黑腹果蝇的结果相关，在黑腹果蝇中已鉴定出两个钠通道基因。
