Abstract: Objective To detect the kdr gene mutations in the field populations of Aedes albopictus from China and preliminarily clarify its adaptive evolution. Methods The mosquito larvae and pupae were dip-samples from breeding sites from Yangpu district in Shanghai, Nanjing city in Jiangsu province, Hangzhou city in Zhejiang province, and Jinghong city in Yunnan province, in China, and brought back to insectary to rise till adults. The mosquito adults were also collected directly in the fields using BG-trap or sucking tube. The single individual genomic DNA of Ae. albopictus was extracted after species identification. The VGSC gene fragments were amplified by PCR, which were sequenced and analyzed for detection of the kdr mutations. The genotypic linkage disequilibrium and Hardy-Weinberg equilibrium(HWE) was tested by GENPOP software. Results A total of 299 individuals collected from four field populations of Ae. albopictus were analyzed. There were two positions showed mutations including codon 1532 and 1534 of kdr gene. Two alleles at codon 1532 were wildtype ATC/I and mutant ACC/T, with frequencies 91.30% and 8.70%, respectively. Five alleles at codon 1534 were wildtype TTC/F, mutant allele TCC/S, TCG/S, TTG/L, and TGC/C, with frequencies of 45.99%, 52.01%, 0.33%, 1.00%, and 0.67%, respectively. There were 27 individuals(9.03%) with both mutations in 1532 and 1534 at the same time. The test results showed that the population conformed to HWE(P > 0.001), and the two loci were genetic linkage (P < 0.01). Conclusion This study first reported the novel mutant allele I1532T, and found a mutant allele TCG/S at the codon 1534 of Ae. albopictus in China. More important is a new challenge that an individual harbors two codons of simultaneous mutations. The results suggested that they should be resistant to pyrethroid insecticides. The multiple site mutations may be resulted from the selection pressure of insecticides.

Key words: Aedes albopictus, Knockdown resistance gene, Gene mutation, Resistance

摘要： 目的 检测我国白纹伊蚊现场群体的击倒抗性（kdr）基因突变，初步探讨现场群体kdr基因的适应性进化。方法 2016年10月及2017年6-10月，在上海市杨浦区、江苏省南京市、浙江省杭州市和云南省景洪市外环境或公园白纹伊蚊孳生地舀取蚊幼虫和蛹，带回实验室饲养至成蚊；或直接采集成蚊。鉴定种类后，单只蚊抽提基因组DNA，PCR扩增神经细胞膜上电压门控钠离子通道（VGSC）基因部分片段，测序并进行序列分析，检测kdr基因突变情况，应用GENPOP软件进行连锁不平衡和哈代-温伯格平衡检验。结果 共检测4个现场群体299只白纹伊蚊，发现kdr基因I1532和F1534位点突变。1532位点有2种等位基因，分别为野生型ATC/I（91.30%）和突变型ACC/T（8.70%）；1534位点共有5种等位基因，分别为野生型TTC/F，突变型TCC/S、TCG/S、TTG/L和TGC/C，等位基因频率为45.99%、52.01%、0.33%、1.00%和0.67%。2个位点同时突变的个体共有27个（9.03%）。群体符合哈代-温伯格平衡（P > 0.001），2个位点在遗传中为连锁关联关系（P < 0.01）。结论 首次记录了我国白纹伊蚊群体在1532位点存在突变I1532T和1534位点新的突变等位基因TCG/S，以及1个个体存在2个位点同时突变的新问题。结果提示，4个白纹伊蚊现场群体对菊酯类杀虫剂已产生抗性，多个位点突变可能与杀虫剂的选择压力有关。

关键词: 白纹伊蚊, 击倒抗性基因, 基因突变, 抗药性