质粒pBR322的γ辐射损伤效应  

THE EFFECT OF γ-RAY IRRADIATION ON PLASMID pBR 322 DNA

作　　者：周丽君[1] 方允中[1] 章扬培[1] 魏康[1] 

机构地区：[1]军事医学科学院放射医学研究所

出　　处：《辐射研究与辐射工艺学报》1993年第1期28-30,57,共4页Journal of Radiation Research and Radiation Processing

摘　　要：采用琼脂糖凝胶电泳及激光密度扫描仪和积分分析,观察了质粒pBR 322 DNA的γ辐射效应。发现随照射剂量的增加,超螺旋质粒所占比例逐渐下降,而开环质粒所占比例相应升高;运用OH自由基清除剂甲酸钠进一步观察到清除OH自由基后,质粒pBR 322的辐射效应大为减轻。结果提示其损伤主要是通过水的辐解产物OH自由基的间接作用而引起的。Using the agarose gel electrophoresis in combination with laser den-sitometer and recording integrator, the effect of γ-ray irradiation on plasmid pBR 322was studied. It was found that the amount of supercoiled (SC) DNA decreased withthe increase of irradiation dose, whereas the nicked circular (OC) DNA increased.Formate, a well known hydroxyl free radical scavenger, could decreased the radiosen-sitivity of the pBR 322 DNA, indicating that the effect of the ^(60)Co irradiation onplasmid was mainly attributable to the indirect action of radiation. Which is resu-lted frorn OH radical produced by the radiolysis of water, giving rise to single stra-nd break of DNA.

关 键 词：Γ辐射 DNA 质粒 放射损伤 

分 类 号：Q345.2[生物学—遗传学]