不同浓度8—MOP诱导的四膜虫rDNA链间交联的产生

本实验采用酶方法在核苷酸水平上检测了8—MOP(8—methoxypsoian)诱导的四膜虫rDNA键间交联的产生。将四膜虫用不同浓度的8—MOP与365nm紫外线照射联合处理,提取其rDNA,再用限制性核酸内切酶ClaI和BamHI消化,经凝胶电泳,Southern转印,分子杂交,自显影等过程,获得最终结果。放射自显影图片显示,当8—MOP浓度≥1μg时,四膜虫rDNA分子产生交联,且随着8—MOP浓度的增加,链间交联的的分子数目也增加,呈现明显的剂量依赖关系。

FORMATION OF DNA INTERSTRAND CROSS-LINKS INDUCED BY DIFFERENT CONCENTRATION OF 8-MOP IN TETRAHYMENA THERMOPHILA

In this work , the formation of 8-MOP (8-methoxy-psoralen) induced DNA interstrand crosslinks in Tetrahymena thermophila was studied at the nucleotide level, using enzymatic method. The rDNA was extracted from log-phase Tetrahymena thermophila cells, which were treated with various concentrations of 8-MOP in combination with long wave length ultraviolet irradiation, and was restricted with BamHI and C1aI. These restricted rDNA from different samples were heated to 100℃ for denaturation prior to being analyzed by agarose gel electrophoresis and Southern hybridizaton. The resulting autoradiograph showed that the amount of the double-stranded rDNA fragments increased when the amount of 8-MOP used was increased. It can be seen that DAN in vivo becomes more cross-linked as the concentration of 8-MOP increased, showing a clear dose dependent relationship.