Giaccia A J, Richardson E, Denko N, Stamato T D
Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania 19104.
Somat Cell Mol Genet. 1989 Jan;15(1):71-7. doi: 10.1007/BF01534671.
We investigated the dominant/recessive nature of the XR-1 mutant locus in intraspecies Chinese hamster ovary (CHO) hybrids and interspecies hybrids with human cell lines that possess different radioresistances. The XR-1 cell is abnormally sensitive to killing by gamma rays in the G1 phase of the cell cycle, while late-S-phase cells have wild-type resistance. [3H]Thymidine selection was used to eliminate the resistant S-phase population. In both intraspecies and interspecies hybrids, the XR-1 mutation is recessive to the wild-type cell and is not influenced by differences in chromosome ploidy. Analysis of hybrids between human ataxia telangiectasia fibroblasts AT5BI and XR-1 cells revealed that they possess different genetic defects as they complemented each other in three of four hybrids tested. These data suggest that the XR-1 locus is evolutionarily conserved between hamster and human cells.
我们研究了中国仓鼠卵巢（CHO）种内杂交体以及与具有不同辐射抗性的人类细胞系的种间杂交体中XR - 1突变位点的显性/隐性性质。XR - 1细胞在细胞周期的G1期对γ射线杀伤异常敏感，而S期后期的细胞具有野生型抗性。利用[³H]胸腺嘧啶核苷选择来消除抗性S期群体。在种内和种间杂交体中，XR - 1突变相对于野生型细胞是隐性的，并且不受染色体倍性差异的影响。对人类共济失调毛细血管扩张症成纤维细胞AT5BI和XR - 1细胞之间杂交体的分析表明，它们具有不同的遗传缺陷，因为在四个测试的杂交体中有三个中它们相互互补。这些数据表明，XR - 1位点在仓鼠和人类细胞之间在进化上是保守的。
