中山市白纹伊蚊现场种群击倒抗性基因检测分析

Detection and analysis of the knockdown resistance gene in the field populations of Aedes albopictus in Zhongshan

目的检测广东省中山市不同生境白纹伊蚊现场种群的击倒抗性(kdr)基因突变,了解其抗药性水平,探讨kdr基因突变与性别间抗药性差异的关系,为蚊虫的抗性机制研究以及科学防制提供依据。方法2019年8-11月在中山市选择5个生境采集白纹伊蚊幼虫和蛹569只,实验室饲养至成虫,提取单只成蚊基因组DNA,扩增并测序分析kdr基因突变情况,并应用χ^(2)检验比较不同性别成蚊kdr基因突变的差异。结果共检测中山市5个生境的白纹伊蚊569只。kdr基因1532位点未发生突变,等位基因为野生型ATC/I,基因型为F/F。1534位点存在突变,有5种等位基因,分别为野生型TTC/F,突变型TTG/L、TCC/S、TCG/S、TGC/C;8种基因型分别为野生型纯合子F/F,野生突变型杂合子F/L、F/S和F/C,突变型纯合子L/L和S/S,突变型杂合子L/S和L/C。雌雄蚊个体间kdr基因1534位点的突变差异无统计学意义(χ^(2)=0.798,P>0.05)。结论中山市白纹伊蚊kdr基因突变频率较高,提示对拟除虫菊酯类杀虫剂已产生抗性,雌雄蚊在kdr基因突变上没有明显的差异。

This study aimed to investigate the mutations in the knockdown resistance gene(kdr)in field populations of Aedes albopictus in Zhongshan,Guangdong Province,and to explore the relationship between kdr gene mutations and differences in resistance between sexes,with the goal of understanding resistance levels and providing a reference for scientific control of Ae.albopictus.Larvae and pupae of Ae.albopictus were collected from five different habitats from August to November in Zhongshan and reared to adults in the laboratory.Genomic DNA was extracted from each mosquito.The kdr gene was amplified and sequenced to analyze its mutations.Chi-square tests were used to compare the differences in kdr gene mutations between sexes in adult mosquitoes.A total of 569 Ae.albopictus were analyzed in five habitats in Zhongshan.At codon 1532,the allele was wild-type ATC/I,and the genotype was F/F;no mutations were observed.Five alleles were observed at codon 1534:one wild-type TTC/F allele,and four mutant TTG/L,TCC/S,TCG/S and TGC/C alleles.Eight genotypes were homozygous wild-type F/F;wild/mutant heterozygous F/L,F/S and F/C;homozygous mutant L/L and S/S;and mutant heterozygous L/S and L/C.The results showed that the differences in kdr gene mutations at codon 1534 in adult mosquitoes between sexes were not statistically significant(χ^(2)=0.798,P>0.05).We concluded that the frequency of kdr mutations in Ae.albopictus is high in Zhongshan,thus suggesting that Ae.albopictus may be resistant to pyrethroid insecticides.No significant difference in kdr gene mutations between male and female Ae.albopictus was observed.