鸡大肠杆菌iss基因的克隆测序及原核表达

本实验对鸡大肠杆菌O2血清型菌株进行iss基因克隆测序，并在此基础上设计出两对套式引物，分别对含信号肽Miss基因序列和不含信号肽Miss基因序列进行扩增，并与原核表达载体pGEX-6p-1连接进行原核表达。iss基因克隆测序的结果与两组国外发表Miss基因序列进行比对，其同源性达100％。SDS—PAGE鉴定显示融合蛋白获得了较理想的表达，融合蛋白分子量分别约为36kD和33kD。

Cloning,sequencing and expression of iss in avian Escherichia coli isolates

In order to determine the antigenicity of Iss and its potential for eliciting immunity in chickens,the increased serum survival gene(iss) was amplified. The specific amplicon was cloned into T vector, and determined. The iss gene removed form T vector was cloned into the plasmid vector pGEX-6p-1 to be a recombinant expression plasmid which was transformed into a protease-deficient E.coli and expressed as fusion protein linked with the GST.