变形链球菌DNA酶切片段在大肠杆菌中克隆的研究

Studies on cloning fragment from streptococcus mutans DNA in E. coli.

将变链菌染色体DNA和pBR322 DNA,分别用HindⅢ酶切,再用T_4DNA连接酶连接,转化到大肠杆菌R_5受体菌中。根据插入灭活的原理,筛选Ap^r、Tc^s菌株,并经抗药性、琼脂糖凝胶电泳,酶切、核酸杂交及再转化等试验证明,已将变链菌DNA酶切片段克隆到大肠杆菌中,获得2627个克隆株,建立了基因库。为筛选变链菌保护性抗原基因,进一步研制基因工程龋齿菌苗奠定了基础。

The chromosomal DNA from streptoccu the mutans ingbritt (serotype c) and vector plasmid DNA from E. coli pBR32 strain were digested separately with Hindl Ⅲ restriction endonuclease, mixed, ligated by T4DNA ligated. The resultant products were transformed into the host cell system of E. coli R5 strain. According to the principle of insertional inactivation, Ap' TC' Clone strains were selected. Antibiotic resistance, agarose gel electrophoresis, rstriction endonuclease analysis, molecular hybridization and re-transform ests showed that chromosomal DNA from S. mutans was cloned into E. coli. 2627 clone strainswere obtained. Present study will lay a foundation for screen of the protective antigen genes from S. mutans and study of genetic engineering vaccine of dental caries.