Spectra of spontaneous and X-ray-induced mutations at the hprt locus in related human lymphoblast cell lines that express wild-type or mutant p53.
Spectra of spontaneous and X-ray-induced mutations at the hprt locus in related human lymphoblast cell lines that express wild-type or mutant p53.
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DOI：
10.2307/3579211
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发表时间：
1995-09
影响因子：
3.4
通讯作者：
E. Phillips;F. Xia;K. Kelsey;H. Liber
中科院分区：
文献类型：
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作者：
E. Phillips;F. Xia;K. Kelsey;H. Liber
先前的研究表明，WTK1 人类淋巴母细胞具有放射抗性，但比密切相关的系 TK6 对 X 射线诱导的突变更敏感。此外，WTK1 细胞含有突变型 p53，而 TK6 细胞中 p53 是野生型。在这项工作中，我们检查了 WTK1 细胞中半合子 hprt 基因座的 68 个 X 射线诱导突变体和 56 个自发突变体的光谱。通过Southern印迹和多重聚合酶链式反应(PCR)对诱导光谱进行分类；有 19 个点突变 (28%) 具有未改变的 Southern 印迹或 PCR 模式，26 个 (38%) 部分缺失或重排以及 23 个 (34%) 完全基因缺失。自发谱包括 25 个（45%）点突变、22 个（39%）部分缺失和 9 个（16%）完全基因缺失。将这些突变谱与 TK6 细胞的突变谱进行比较。尽管先前报道了 tk 基因座突变谱的明显差异，但总的来说，这两种细胞系中 hprt 基因座 X 射线诱导或自发突变的谱没有显着差异。虽然 X 辐射后 tk 发生大规模变化的比例有所增加，但 hprt 基因座的突变谱显示，WTK1 细胞中所有类型的突变均按比例增加。然而，WTK1 细胞中 hprt 位点内部部分缺失突变的比例大约是 TK6 细胞的 2 倍。
Previous work showed that WTK1 human lymphoblastoid cells are radioresistant but more sensitive to X-ray-induced mutation than the closely related line TK6. In addition, WTK1 cells contain a mutant p53 while in TK6 cells p53 is wild-type. In this work, we examined the spectra of 68 X-ray-induced and 56 spontaneous mutants at the hemizygous hprt locus in WTK1 cells. The induced spectra were classified by Southern blot and multiplex polymerase chain reaction (PCR); there were 19 point mutations (28%) with an unaltered Southern blot or PCR pattern, 26 (38%) partial deletions or rearrangements and 23 (34%) complete gene deletions. The spontaneous spectrum included 25 (45%) point mutations, 22 (39%) partial deletions and 9 (16%) complete gene deletions. These spectra of mutations were compared to those of TK6 cells. Although distinct differences in the spectra of mutations at the tk locus were reported previously, overall there is no significant difference in the spectra of X-ray-induced or spontaneous mutations at the hprt locus in these two cell lines. While there was an increase in the proportion of large-scale changes that occurred at tk after X irradiation, the spectrum of mutations at the hprt locus shows all classes of mutations increasing proportionately in WTK1 cells. However, the proportion of internal partial deletion mutations at the hprt locus was about 2 times more frequent in WTK1 than in TK6 cells.