肠杆菌4.5S RNA基因单链构象多态性的比较研究

COMPARATIVE STUDY OF SINGLE STRAND CONFORMATION POLYMORPHISM OF 4. 5S RNA GENE IN ENTEROBACTERIA

本文对大肠杆菌(Escherichia coli)不同菌株和肠杆菌科(Enterobacteriaceae)不同属其他三种菌株,即普通变形菌(Proteus vulgaris)、粘质沙雷氏菌(Serratia marcescens)和产气肠杆菌(Enterobacter aerogenes),分别进行4.5S RNA基因聚合酶链式反应(PCR),然后对扩增产物作依赖于序列的单链构象多态性(SSCP)分析.实验结果表明,上述细菌4.5S RNA基因的大小和正链构象均无可觉察的差异,仅产气肠杆菌的负链构象有明显不同.由此可见4.5S RNA基因在进化上相当保守,产气肠杆菌4.5S RNA基因的序列虽有改变,仍能维持其有义链的基本构象.

A recently developed technique,non-isotopic single strand conformation polymorphism analysis (PCR-SSCP), was applied to study the conserved feature of 4. 5S RNA gene in enterobacteria. The 4. 5S RNA gene was amplified by the polymerase chain reaction,using the template DNA extracted respectively from five strains of Escherichia coli and three strains of different genera in Enterobacteriaceae ,i. e. Proteus vulgaris,Ser-ratia marcescens and Enterobacter aerogenes. The PCR products were then carried out SSCP analysis. The experimental results showed that there seemed to be no detectable differences in the size and single strand conformation of 4. 5S RNA genes from above strains,except the negative strand conformation of Enterobacter aerogenes. Thus it can be seen that the secondary structures of 4. 5S RNA gene in enterobacteria are quite conservative .