【摘要】 用细小病毒H-1为探针,可在人细胞中检测由紫外线照射诱导的三种不同致突变途径.直接突变产生于细胞的结构性复制(或修复)功能对受损DNA模板的复制;间接无靶突变和间接有靶突变分别产生于紫外线诱导的易错修复功能对完整模板和模板上的靶损伤的作用.在低剂量范围内,间接无靶突变在某些DNA毒剂诱导的细胞突变中起主要作用.某些DNA损伤,如烷化剂诱导的次级损伤(无碱基位损伤)可作为诱导性易错修复功能的靶损伤.更多还原

【Abstract】 Three different mutagenic pathways induced by ultraviolet irradiation can be distinguished in human cells by use of parvoviral probe. Direct mutagenesis occurs as a response of the cellular constitutive replication machinary (or repair function) to lesions in viral DNA. Indirect untargeted mutagenesis is conditioned on providing cells an inducible error-prone repair function which replicates viral DNA less accurately. Indirect targeted mutagenesis is also conditioned on a cell-inducing treatment, but is directed at special lesions in viral DNA. Within the low dose range, the indirect untargeted mutagenesis plays a main role in the entire mutagenic charge loaded on cells by certain environmental genotoxic agents. Certain DNA lesions, apurinic sites, the secondary DNA lesions induced by alkylating agents, for example, are the proper substrates of the inducible error-prone repair activity.更多还原