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【目的】SC1通道(sodium channel 1)是昆虫体内一种重要的离子通道,被认为是一种开发新型杀虫剂的神经靶标。本研究拟克隆禾谷缢管蚜Rhopalosiphum padi的SC1通道基因,并初步分析其生理功能及其与SC1类通道、电压门控钠离子通道、电压门控钙离子通道的进化关系。【方法】采用RT-PCR技术,克隆了禾谷缢管蚜SC1基因完整的开放阅读框;利用实时荧光定量PCR技术,分析禾谷缢管蚜成蚜在不同浓度的高效氯氟氰菊酯诱导下SC1基因表达变化。【结果】获得了禾谷缢管蚜SC1基因(命名为RSC1)完整的开放阅读框(Gen Bank登录号为KU640190),其长度6 687bp,编码2 228个氨基酸。RSC1具有SC1通道的结构特征,有一个不同于电压门控钠离子通道和电压门控钙离子通道的特殊DEEA模体(motif)。系统进化分析结果显示,RSC1与电压门控钠离子通道组成一个进化枝,电压门控钙离子通道组成另外一个进化枝,SC1与电压门控钠离子通道在进化上有更近的起源关系。实时荧光定量PCR分析结果表明,LC15,LC35和LC503种剂量的高效氯氟氰菊酯处理6 h后,禾谷缢管蚜RSC1基因表达量相对于清水对照显著下调,表达量分别为对照的0.57,0.82和0.78倍;3种剂量的高效氯氟氰菊酯处理24 h后,禾谷缢管蚜RSC1基因表达量分别为对照的2.19,1.33和1.19倍,其中LC15(0.1484 mg/L)胁迫下RSC1基因的表达量显著上调。【结论】SC1类通道与电压门控钠离子通道在进化起源上有更近的关系。RSC1通道可能是高效氯氟氰菊酯的次级靶标。由于RSC1和其同源基因只存在于节肢动物中,脊椎动物尚未发现该类基因,因此这类通道可能作为开发新型杀虫剂的神经靶标。
【Objective】 Sodium channel 1 (SC1) is an important ion channel in insects and is considered as a neural target for developing new insecticides. In this study, SC1 gene of Rhopalosiphum padi was cloned and its physiological function and its evolutionary relationship with SC1 channel, voltage-gated sodium channel and voltage-gated calcium channel were preliminary analyzed. 【Method】 The full-length open reading frame of SC1 gene of Aphis gossypii was cloned by RT-PCR. Real-time quantitative PCR was used to analyze the effects of different concentrations of lambda-cyhalothrin Under SC1 gene expression changes. 【Result】 The complete open reading frame (GenBank accession number KU640190) of the SC1 gene (named as RSC1) was obtained and its length is 6 687 bp, encoding 228 amino acids. RSC1 has the structural features of the SC1 channel, with a special DEEA motif that is different from voltage-gated sodium channels and voltage-gated calcium channels. Phylogenetic analysis showed that RSC1 and voltage-gated sodium channels form a clade, the voltage-gated Ca2 + channels form another clade, and SC1 has a closer evolutionary relationship with voltage-gated sodium channels. The results of real-time PCR showed that RSC1 mRNA expression was significantly down-regulated compared with fresh water control after 6 h treatment of LC15, LC35 and LC50 doses of lambda-cyhalothrin, the expression levels were 0.57 , 0.82 and 0.78 times, respectively. RSC1 gene expression in H. cerealis was 2.19,1.33 and 1.19 times higher than that in the control at 24 and 24 h after three doses of lambda-cyhalothrin, respectively. LC15 (0.1484 mg / L) The expression of RSC1 gene was significantly upregulated. 【Conclusion】 SC1-like channels are more closely related to the origin of voltage-gated sodium channels. The RSC1 channel may be a secondary target of lambda-cyhalothrin. Since RSC1 and its homologous genes are present only in arthropods, no such gene has been found in vertebrates, and therefore such channels may serve as neural targets for the development of novel insecticides.