Spatial distribution of mutations in voltage-gated sodium channel genes of Culex pipiens pallens/Culex pipiens quinquefasciatus in China

Abstract

Abstract Background Culex pipiens pallens and Culex pipiens quinquefasciatus are the main species of bloodsucking mosquitoes in China. The aim of this study is to understand the current situation of VGSC genes of Cx. pipiens pallens and Cx. pipiens quinquefasciarus in China and the impact of pyrethroid insecticides on the long-term evolution of mosquito populations, providing a basis for scientific prevention and control. Methods Study 28 geographic populations in 22 provinces. Partial fragments of the voltage-gated sodium channel (VGSC) gene on the nerve cell membrane were amplified by PCR. The mutation, mutation frequency and phylogenetic were analyzed after sequencing. Results There were 6 alleles and 6 genotypes at the L1014 locus, which were wild-type TTA / L and CTA / L, mutant TTT / F, TTC / F, TCT / S and TCA / S. The proportion of homozygous L/L and mutant homozygous F/F in genotype is similar, which are more than 30.00% The geographic populations with frequency less than 20.00% are mainly concentrated in the north of 38 ° N, and the geographic populations with frequency more than 80.00% in the south of 30 ° N. frequency increases with the decrease of latitude, and frequency has urban tendency. mutation is correlated with introns. The mutant allele TCA / S has only one intron, TTT / F has three introns, and the wild allele TTA / L has 17 introns. Conclusions The allelic genotype of Culex pipiens pallens/Culex pipiens quinquefasciatus in China is diversified, and the resistance of Culex pipiens pallens/Culex pipiens quinquefasciatus in most areas has been developed, and the degree of resistance is regional. gene has a polymorphism in its adjacent downstream intron and is related to mutation.