Polymorphism Analysis Of Formyl Peptide Receptor 1 Gene Of Rattus Tanezumi In Yunnan Province

Objective:To obtain and analyze the FPR1 gene sequence of Rattus tanezumi,the main host of rattus tanezumi plague foci in Yunnan Province.To investigate the distribution of single nucleotide polymorphisms(SNPS)of FPR1 gene in rattus tanezumi,and to screen out the possible plague resistance alleles of FPR1 gene in rattus tanezumi.Combined with the epidemiological characteristics of rattus tanezumi plague in Yunnan province,the differences of FPR1 gene in rattus tanezumi among different regions were analyzed.Methods:In this study,the plague foci of house rat in Yunnan Province were: The COI gene sequence of rattus tanezumi seven different geographical populations in Dali,Baoshan,Dehong,Lincang,Yuxi,Wenshan and Xishuangbanna prefectures was used to identify the species and genotype,and to collect basic data for further study on the genetic characteristics of rattus tanezumi populations in different regions and the epidemiological characteristics of rattus plague from the host perspective.Firstly,according to the obtained FPR1 c DNA gene sequence,the middle sequence primers of FPR1 gene of Rattus tanezumi were designed.The full-length sequence of FPRA was obtained by RACE experiment.According to the amplification of the full-length sequence,the primers for amplifying the full-length sequence of FPR1 gene were designed.A total of 620 Rattus tanezumi copies collected from Dali,Baoshan,Dehong,Lincang,Yuxi,Wenshan and Xishuangbanna prefectures from 2016 to 2022 were amplified to obtain the full-length fragment of FRP1 gene.After bidirectional sequencing,DNASTAR was used to assemble the sequencing results and detect single nucleotide polymorphism sites.Based on the spatial location characteristics of the human FPRI R19 OW plague resistance locus,the possible plague resistance alleles of Rattus tanezumi were screened.The amino acid sequence of Rattus tanezumi was analyzed by a series of software and website programs,and the FPR1 genotype,frequency and allele frequency were compared between the old epidemic area and the new epidemic area of Yunnan house rat plague.SPSS 25 was used to process the data,and chi-square analysis was used to analyze the difference in the rate of this study,and the test level was α =0.05.Results:1.High haplotype diversity and low nucleotide diversity patterns were observed in the populations of Rattus tanezumi in the 7 cities of Yunnan province.The COI gene sequences of Rattus tanezumi were divided into two major clusters.2.Through a series of experiments,the full length sequence of FPR1 gene of the Rattus tanezumi was obtained,with a size of 1063 bp.3.There were 7 SNP sites in FPR1 of Rattus tanezumi in the above areas of Yunnan province,including 2 synonymous mutation sites and 5 missense mutation sites.The mutation rate of site K195D(584 locus)of FPR1 gene was 77.8% and 25.4% in the epidemic foci of 1950 s and 1980 s,respectively.When α=0.05,there was a significant difference in the mutation rate between Endemic foci in 1950 s and new foci in 1980 s by chi-square test,and this site and human FPR1R190 W mutation were both located in the second outer ring,which suggested that this site might be the resistance allele of Yersinia pestis.Conclusion:1.Based on the COI gene sequence of Rattus tanezumi,the Rattus tanezumi in the above regions of Yunnan Province did not show a large distance genetic differentiation,but showed genetic diversity.2.Rattus tanezumi FPR1 based on the presence of multiple SNP loci of selective significance.3.The K195D(584 locus)of FPR1 in Rattus tanezumi may be the resistance allele of Yersinia pestis.The mutation of FPR1 in host animals may be the cause of the high incidence of house rat plague in Dehong,Baoshan of Yunnan Province.