Jeggo P A
Mutat Res. 1985 May;145(3):171-6. doi: 10.1016/0167-8817(85)90024-0.
6 mutants of the CHO cell line hypersensitive to ionizing radiation have been previously described (Jeggo et al., 1982; Jeggo and Kemp, 1983). In this report, the degree of radiosensitivity of DNA synthesis in these mutant strains has been investigated. 5 of the 6 mutant strains showed a greater degree of inhibition of DNA synthesis following gamma-irradiation compared to the wild-type strains, one mutant showed a similar response to the parent strain. An analysis of the size of the DNA made after irradiation in mutant and wild-type strains indicated that initiation events were more inhibited than chain elongations. This enhanced radiosensitivity is in contrast to results observed using ataxia telangiectasia fibroblasts, in which DNA synthesis is radioresistant in comparison to normal skin fibroblasts. These results are interpreted on the basis of sensitivity resulting from a defect in DNA repair in these mutant strains.
先前已描述过6种对电离辐射敏感的CHO细胞系突变体（Jeggo等人，1982年；Jeggo和Kemp，1983年）。在本报告中，研究了这些突变株中DNA合成的放射敏感性程度。6个突变株中的5个在γ射线照射后显示出比野生型株对DNA合成的抑制程度更高，1个突变株显示出与亲本株相似的反应。对突变株和野生型株照射后产生的DNA大小的分析表明，起始事件比链延伸受到的抑制更大。这种增强的放射敏感性与使用共济失调毛细血管扩张症成纤维细胞观察到的结果相反，在共济失调毛细血管扩张症成纤维细胞中，与正常皮肤成纤维细胞相比，DNA合成具有放射抗性。基于这些突变株中DNA修复缺陷导致的敏感性对这些结果进行了解释。
