Investigation of the frequency of kdr mutation of voltage-gated sodium channel in Anopheles sinensis in Yunnan Province / 中国热带医学

ABSTRACT

@#Abstract Objective　To understand the kdr (knockdown resistance, kdr) gene mutation of the voltage-gated sodium channel (VGSC) of Anopheles sinensis in Yunnan Province. Methods　From 2018 to 2019, mosquitoes were collected in Luoping County, Suijiang County, Tengchong City, Yingjiang County, Yuanjiang County and Mengla County in Yunnan Province. The collected mosquitoes were morphologically identified as Anopheles sinensis and genomic DNA was extracted by kits. The DNA templates were sequenced after PCR amplification and the sequencing results were identify as Anopheles sinensis by homology alignment in NCBI. After the ⅡS5 and ⅡS6 fragments of the sodium channels in Anopheles sinensis were amplified and sequenced, the sequencing results were multiple aligned by DNAMAN software, and the mutations were analyzed one by one with BioEdit software to determine the kdr allele types and genotypes, and the frequencies were calculated. Results This survey amplified 287 sequences, and the sequence maps showed that 1014 loci had three alleles, including wild type TTG/L (89.20%), mutant type TTT/F (9.76%) and TCG/S (1.04%). Five genotypes homozygous wildtype L/L (85.02%), homozygous mutant F/F (6.27%) and S/S (0.35%), heterozygous mutant L/F (6.97%) and L/S (1.39%). The wild type allele TTG/L was the main allele in six sampling sites except Suijiang County. The frequency of wild type allele in Tengchong City was the highest (100.00%). That is, no mutation was detected, while the rest of counties occurred different degrees of mutation at 1014 loci. The frequency of mutant allele in Suijiang County was the highest, reaching 55.68%. Luoping County, Mengla County and Suijiang County had two mutant types. Yingjiang County and Yuanjiang County had one heterozygous mutant L/F. Conclusion　Wild type L1014 (TTG/L) is still dominant in most areas of Yunnan Province. The kdr mutation type is mainly L1014F, followed by L1014S, and the mutation frequency is lower than that in central provinces of China.