The Study Of Pertinence Between CD14Gene Polymorphism And Susceptibility Of Bovine Tuberculosis

Tuberculosis is a typical chronic infectious diseases caused by Mycobacteriumtuberculosis, which can infected people, livestock, poultry. In recent years, thetuberculosis incidence is rising in our country and others due to the emergence ofdrug-resistant strains of Mycobacterium tuberculosis and widely disseminated, whichbring a huge threat to yellow cattle industry and human health. the CD14genepolymorphism and susceptibility to tuberculosis were studyed through the analysis ofthe yellow cattle CD14gene sequence for the first time in order to find a yellow cattletuberculosis higher risk SNP loci of the CD14gene and susceptible genotypes withhigh risk, which provided new ideas for the control of yellow cattle tuberculosis andyellow cattle genetics and breeding. the contents and results of this study are asfollows:1. Effect evaluation of different diagnostic methods of yellow cattle tuberculosisDetection of yellow cattle sample amounted to459. A total of382yellow cattlesfrom Luoyang, Yiyang, Lankao, as well as all four counties of Nanyang were throughPPD test. Detection blood sampling of IFN-γ-ELISA was233,156among them comesfrom the PPD testing cattle, and the rest77from the abattoir around Luoyang. Resultsshowed:9samples were positive by PPD detection,2were suspicious, the detection ofpositive rate was2.36%,3samples were positive by IFN-γ-ELISA detection, thepositive rate was1.29%, the sensitivity and accuracy of IFN-γ-ELISA were higherthan PPD; Dual detection test, in favour of yellow cattle tuberculosis diagnosis, wasmore accurate than a single method.2. Bioinformatic analysis of yellow cattle CD14geneThe primer of yellow cattle CD14gene were designed according to the CD14gene sequence of Holstein cattles published in GenBank, through segmentedamplification and sequencing by the method of PCR,2969bp sequence containing complete coding region of CD14and the5’and3’ non-coding region was got aftersplicing. The result showed that: the ORF of yellow cattle CD14gene contained966bp encoding321amino acids, The homology of CD14gene of yellow cattle andHolstein cattle, buffalo, sheep, goats, pigs, monkeys, gorillas, human, mousedecreased in turn, and were99.8%、98.2%、96.8%、92.8%、83.5%、79.8%、79.7%、79.5%、71.9%, respectively. The results of categorize from phylogenetic treewere similar with the traditional classification results. There is no transmembranedomains by means of protein structure prediction of CD14gene sequence in Yellowcattle.3.Screening of SNPs CD14and correlation analysis of susceptibility totuberculosisBlood sample were divided into tuberculosis cattle groups (26) and normalcontrol group (60). According to sequence the peak figure, the test results were readed,SNPs heterozygosity were quested, C-251T, A-181G, A270G, A336G, A367G, T729G,A777G, A1060G, and T1080G, a total of9SNPs(MAF＞0.01), were discovered.Whether the allele frequencies in the control group coincided the Hardy-Weinberggenetic equilibrium were detected using Chi-square test detection,9SNPs wereanalyzed by statistical analysis software. Allelic analysis results showed: The Genefrequency of C-251T alleles C, A-181G alleles A, A270G alleles A, G729T alleles Gand G1080T alleles G between the healthy group and the yellow cattle tuberculosisgroup were significantly different in distribution exist(P＜0.05), the remaining4SNPsalleles in yellow cattle tuberculosis and health group of distribution does not existsignificant differences(P＞0.05). Further genetic analysis showed that: the distributionof different genotypes of5SNPs(C-251T, A336G, A367G, and A777G and A1060G)between health and tuberculosis groups are not notable(P＞0.05), A-181G, A270G,G729T and G1080T SNPs were significantly associated with susceptibility to yellowcattle tuberculosis(P＜0.05), the genotypes: The frequency distribution of-181GG,270GG,729GG,1080GG in yellow cattle tuberculosis group was significantly higherthan the healthy control group; the5SNPs: C-251T, A336G, A367G, A777G andA1060G of cattle CD14gene and the susceptibility of yellow cattle tuberculosis wasnot significant correlation under5modes of genetic analysis (P＞0.05); We find A-181G, A270G, G729T and G1080T SNP associated with tuberculosis significantly forthe first time(P<0.05), the genotype of-181GG,270GG,729GG,1080GG were highrisk susceptible factors for yellow cattle tuberculosis.