RT PCR克隆辐射敏感细胞及其亲本细胞的ku80基因cDNA ,发现辐射敏感细胞的ku80基因与双链断裂DNA末端相互作用的位置存在基因突变 ,用凝胶阻滞和DNA 蛋白质印迹进一步证实突变ku基因编码蛋白结合双链断裂末端DNA的能力下降 ,暗示其细胞辐射敏感性可能与Ku蛋白功能异常有关 RT-PCR cloned ku80 gene cDNA of radiosensitive cells and their parental cells, and found that there is gene mutation in the position of the ku80 gene of the radiation-sensitive cells interacting with the double-stranded DNA ends. The mutation ku gene was further confirmed by gel retardation and DNA western blot The decreased ability of the encoded protein to bind to the double-stranded terminal DNA suggests that its cellular radiosensitivity may be related to Ku protein dysfunction