【作者】 张引红；

【导师】 周忠孝；

【作者基本信息】 山西农业大学 ， 动物遗传育种与繁殖， 2004， 硕士

【摘要】 肠毒素大肠杆菌F18(ECF18)是引起仔猪断奶后水肿和腹泻病的主要病原菌,α-(1,2)岩藻糖转移酶基因(FUT1)是ECF18侵染猪小肠的受体蛋白候选基因。本文采用PCR-RFLP技术对大白猪、长白猪、杜洛克猪、山西黑猪、太原花猪、马身猪6个中外品种共245头猪的E coli F18受体(ECF18R)基因座的FUT1基因进行了研究,检测了各品种猪该基因的遗传变异,并对该基因对产仔性状的影响做了统计分析。 结果表明,Hin6I位点上,大白猪、长白猪、杜洛克猪3个外来猪种均存在多态,且以敏感型(GG型和AG型)居多,平均占91.4%,3个外来猪种的G等位基因频率平均为0.75,AA抗性型个体占少数,平均占8.6%,说明猪群中M307处G→A的突变频率并不高。山西黑猪、太原花猪、马身猪3个本地猪种的所有检测样品都表现为GG型,在该位点上均不存在G→A的突变。各猪种FUT1基因的PCR-RFLP基因型分布x~2检验结果表明,外来猪种与3个本地猪种相比FUT1基因的PCR-RFLP基因型分布差异极显著,3个本地猪种间的FUT1基因的PCR-RFLP基因型分布完全一致。外来猪种间各基因型的分布差异不显著。3个外来猪种的Hardy-Weinberg平衡检验表明,长白猪和杜洛克猪的FUT1基因型分布均处于平衡状态,而大白猪的FUT1基因型分布严重偏离遗传平衡状态(P<0.01)。 群体遗传学分析表明,3个外来猪种遗传变异程度大小依次为长白猪>大白猪>杜洛克猪,且杜洛克猪与长白猪和大白猪遗传变异相差程度较大,长白猪和大白猪相差较小。 用方差分析方法分析FUT1基因型、品种和胎次与产仔性状之间的关系,基因型和品种对猪的总产仔数的影响显著,胎次对总产仔数影响不显著。而基因型、品种和胎次对产活仔数影响均不显著。更多还原

【Abstract】 Abstract Ehterotoxigenic Escherichia coli F18 (ECF18) is a main pathogen that causes edema disease and post-weaning diarrhoea in piglets, and a(l,2)fucosyltransferase(FUT1) gene has been identified as a candidate gene for controlling the expression of the receptor for ECF18 bacteria. The genetic variations at position 307 nucleotide in open reading frame of FUT1 gene in 6 pig breeds (total 245 individuals) from 3 Exotic pig breeds and 3 Chinese native pig breeds were investigated by PCR-RFLP. The association between different genotypes of the FUT1 gene and its resultant litter sizes were evaluated by statistic analysis to test weather the FUT1 gene can be a genetic marker affecting litter sizes or tightly linked with it.The results showed that the genetic polymorphisms of the FUT1 locus were only detected in 3 Exotic pig breeds, 3 Exotic pig breeds possessed 3 different genotypes ; The frequency of A,G allele was 0.25 and 0.75 respectively.It infered that the mutation frequency is lower.All Chinese native pig breeds only presented the susceptible genotype GG. The results indicated that M307 G → A point mutation in the coding region of FUT1 gene might be the key factor determining the expression of the ECF18 receptor , Chinese native pig breeds were absent of the genetic background on the resistance to ECF18 bacteria.The genotype distribution of FUT1 gene between exotic pig breeds and Chinese native pig breeds is signaficantly different by Chi-square test. The test of Hardy-Weinberg equilibrium of exotic pig breeds showed that Large White much diverged from the genetic equilibrium (P<0.01).The results suggested that further study should be done to identify and characterize putative QTL (quantitative trait locus) and the functional gene responsible for the resistance to ECF18 in Chinese native pig breeds.Population genetics analysis consequence showed that the locus of 3 Exotic pig breeds existed medium polymorphism.Univariate analysis of variance components indicated that FUT1 gene and breeds influence significantly total number born, parities influence total number born unsignificantly. FUT1 gene,breeds and parities influence unsignificantly the litter size alive. It is necess parities influence unsignificantly ary to identify the research result by improve sample number.更多还原