Chen D J, Park M S, Campbell E, Oshimura M, Liu P, Zhao Y, White B F, Siciliano M J
Life Sciences Division, Los Alamos National Laboratory, New Mexico 87545.
Genomics. 1992 Aug;13(4):1088-94. doi: 10.1016/0888-7543(92)90023-l.
The Chinese hamster ovary (CHO-K1) cell mutant XRS-6 is defective in rejoining of DNA double-strand breaks and is hypersensitive to X-rays, gamma-rays, and bleomycin. Radiation resistance or sensitivity of somatic cell hybrids constructed from the fusion of XRS-6 cells with primary human fibroblasts strongly correlated with the retention of human chromosome 2 isozyme and molecular markers. Discordancies between some chromosome 2 markers and the radiation resistance phenotype in some of the hybrid cells suggested the location of the X-ray repair cross complementing 5 (XRCC5) gene on the p arm of chromosome 2. Introduction of human chromosome 2 by microcell-mediated chromosome transfer into the radiation-sensitive XRS-6 cells resulted in hybrid cells in which the radiation sensitivity was complemented. The chromosome 2p origin of the complementing human DNA in the microcell hybrids was supported by fluorescent in situ hybridization analysis of human metaphases using human DNA amplified from the hybrids by inter-Alu-PCR as chromosome-painting probes. XRCC5 is therefore provisionally assigned to human chromosome 2p.
中国仓鼠卵巢（CHO-K1）细胞突变体XRS-6在DNA双链断裂修复方面存在缺陷，并且对X射线、γ射线和博来霉素高度敏感。由XRS-6细胞与原代人成纤维细胞融合构建的体细胞杂种的辐射抗性或敏感性与人类2号染色体同工酶和分子标记的保留密切相关。一些杂种细胞中2号染色体的某些标记与辐射抗性表型之间的不一致表明X射线修复交叉互补5（XRCC5）基因位于2号染色体的p臂上。通过微细胞介导的染色体转移将人类2号染色体导入辐射敏感的XRS-6细胞中，产生了辐射敏感性得到互补的杂种细胞。使用通过Alu间PCR从杂种中扩增的人类DNA作为染色体涂染探针，对人类中期染色体进行荧光原位杂交分析，支持了微细胞杂种中互补人类DNA的2号染色体p臂起源。因此，XRCC5暂时被定位到人类2号染色体p臂上。
