摘要
本研究对大肠杆菌进行紫外照射诱变后,获得了通过其内部的SOS修复系统产生的突变菌株,采用异丙醇沉淀法对各组菌种进行质粒DNA提取.通过测定各组OD值,经过比较与分析得出了经紫外处理10min后的大肠杆菌质粒DNA浓度最高,为215ug/ml,其次为正常组的190ug/ml.经紫外照射30min后的大肠杆菌质粒DNA浓度最低,仅为65ug/ml.紫外处理时间与质粒DNA浓度整体呈现下降趋势.初步推测是由于大肠杆菌SOS修复系统的RecA蛋白促进了不完全同源的DNA序列之间的重组,产生大量的错配碱基,从而引起突变,进而影响到其质粒DNA的浓度.
In this research,A mutant E.coli strain was obtained in the experiment of inducing by ultraviolet（UV） radiation combined with SOS repair system of the E.coli.isopropyl alcohol extraction method was used to extract the plasmid DNA in each group which is inducing by the ultraviolet different times.From the results of Agarose gel electrophoresis and measuring the OD values for each group,it was shown that the E.coli after UV inducing 10min had the highest concentration of plasmid DNA for 215 ug / ml.Plasmid DNA of E.coli which was inducing 30min by UV irradiation was only 65ug/ml.It is Predicted that RecA protein of E.coli in SOS repair system Stimulated homology sequence of plasmid DNA had a reorganization which led to mismatched bases,mutations,and made the concentration of plasmid DNA of E.coli had a significant change.
关键词
质粒DNA
SOS修复系统
紫外诱变
异丙醇沉淀法
plasmid
SOS repair system
ultraviolet irradiation mutation
isopropyl alcohol extraction method
