The result showed that the homology rate of pila gene among the 5 avian pathogenic e . coli strains tested and one human e . coli were from 89 . 8 % to 91 . 1 % , and the homology rate of amino acid were from 88 . 5 % to 91 . 8 % . the homology rate of pila gene sequence among 5 avian pathogenic e . coli strains tested and avian pathogenic e . coli reported ( serotype o1 , o2 , o78 ) were from 87 . 8 % to 90 . 2 % , and the homology rate of amino acid were from 84 . 6 % to 91 . 2 % . there had homology in avian pathogenic e . coli . there had some common antigen side in type 1 pili of avian pathogenic e . coli 结果表明：运用msha法检测1型菌毛的检出率为80 ( 36 45 ) ， pcr法的检出率为95 . 5 ( 43 45 ) ， pcr方法用于1型菌毛的检测比msha更加敏感、快速、特异性强；选择5株优势血清型鸡源致病性大肠杆菌代表株( o _ ( 89 ) ， o _ ( 119 ) ， o _ ( 141 ) ， o _ ( 127 ) )的1型菌毛pila基因的pcr扩增片段经纯化后，分别定向克隆到puc18质粒的多克隆位点，构建了含有目的基因片段的克隆质粒，并转化到dh5株大肠杆菌载体菌中，筛选获得阳性克隆菌株。
Phaa , phab and phac were inserted to pbv - 220 with double digest of restriction enduonuclease . the expression vectors of pbv - a , pbv - b and pbv - c were constructed by orientaional cloning . indefication of expression vector with restriction enduonuclease digest showed that phaa phab and phac were in right orfs 将phaa 、 phab和phac片段双酶切后，定向克隆至原核表达载体pbv220 ，构建了三个原核表达载体pbv - a 、 pbv - b和pbv - c ；经酶切分析表明，所克隆的三个基因phaa 、 phab和phac置于表达载体的正确阅读框架下。
The total rna was purified from the germ in the liquid by the guanidine isothiocyantehod method , then the total rna digested by dnase that had not rnase was used for rt - pcr . i change the magnesium ion dencity in the pcr system in order to optimize the pcr condition . at the end i selected the magnesium ion density as 1 . 25 mm . the production of rt - pcr was inserted directionally into pgem ? z ( ampr ) . the pgem ? z ( ampr ) was used to transform e coli jm109 . i got a positive clone through culling and identificatin . the dna sequence inserted into pgem ? z ( ampr ) was sequenced and blasted with the cdna sequence of the # - mannanase mature peptide that got from genbank 分取诱导培养液中的菌体，用异硫氰酸胍法提取总rna ，总rna再经无rna酶的dna酶处理后用于rt ? pcr 。在pcr扩增目的基因时，通过优选扩增体系，使镁离子浓度为1 . 25mm时rt ? pcr可顺利地获得目的基因，并能定向克隆到载体pgem ? 3z ( amp ~ r )中。用克隆载体转化宿主大肠杆菌jm109 ，通过筛选获取阳性克隆子，对阳性克隆子进行酶切与pcr鉴定，并对载体中插入的目的基因进行测序。
To explore the feasibility of ib edible vaccine , we have transformed si gene of ibv into potato and researched the immunogenicity of it ' s expression product . the findings are as follows : 1 . a pair of primers for ibv si gene were designed and synthesized according to the published nucleotide sequence of ibv si gene and multiclone sites of expression vector pbi121 为了探索ibv可食性疫苗的可行性，我们进行了转基因马铃薯表达ibv免疫原基因及其表达产物免疫原性的研究，取得以下结果： 1根据周继勇等报道的ibv - zj971毒株s1基因核苷酸序列和pbi121植物表达载体的多克隆位点，设计并合成引物，以含s1pbs质粒为模板扩增s1基因，将扩增片段定向克隆到pbi121质粒的35s启动子下游。
