【摘要】 质粒pHE5为pBR322的EcoRI—HindⅢ片段由噬菌体T4基因37的EcoRI-HindⅢ片段取代、构建而成,抗Tc基因的启动基因被破坏。在抗Tc结构基因前插入新的启动基因,可以使抗Tc功能恢复,以此可以筛选各种启动基因。我们用pHE5构建了含大肠杆菌启动基因的重组质粒800株,对它们抗四环素程度的分布作了测定,制作了重组质粒pTP210、pTP213的限制性酶切图谱,并且就应用这二个质粒作为真核基因表达运载体的可能性进行了初步讨论。更多还原

【Abstract】 pHE5 is a hybrid plasmid constructed through the substitution of the EcoRI-HindIII fragment of pBR322 by a specific DNA fragment of phage T4.Thus,the promoter region of Tcr of pBR322 became impaired.The Tc resistance can be resumed upon insertion of a foreign promoter upstream of the Tcr structural gene.This provides us with a system for screening the promoters.Using plasmid pHE5,we have constructed hybrid plasmids containing promoters of Escherichia coli and about 800 Tcr clones have been obtained.The distribution of the levels of Tc resistance have been determined.Among the plasmids showing higher levels of Tc resistance,pTP210 and pTP213 have been further analyzed and their restriction sites mapped.The possibility of using these plasmids as vectors in the expression of eukaryotic genes has been discussed.更多还原