Loss of heterozygosity in yeast can occur by ultraviolet irradiation during the S phase of the cell cycle
Loss of heterozygosity in yeast can occur by ultraviolet irradiation during the S phase of the cell cycle
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DOI：
10.1016/j.mrfmmm.2006.04.001
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发表时间：
2006-08-30
影响因子：
2.3
通讯作者：
Yamamoto, Kazuo
中科院分区：
文献类型：
--
作者：
Daigaku, Yasukazu;Mashiko, Satsuki;Yamamoto, Kazuo
确定杂合性缺失（洛）的CANI/canI Delta杂合等位基因用于研究暴露于紫外线（UV）光的酿酒酵母细胞在细胞周期的不同点的重组。利用该等位基因，在细胞暴露于UV辐射后，重组事件可以被检测为刀豆氨酸抗性突变，因为洛缺失事件的显著部分似乎是由同源染色体之间的重组引起的。相对于处于细胞周期其他点的细胞或非同步化细胞，辐射在处于细胞周期S期的细胞中引起更高水平的洛缺失。与此相反，核苷酸切除修复的失活取消了细胞周期特异性诱导的UV的洛。我们假设，DNA损伤，如果没有修复，被转换成双链断裂停滞复制过程中，这些断裂可以通过重组修复使用非姐妹染色单体，也可能是姐妹染色单体。我们认为，洛缺失可能是酵母细胞从病变处停滞的复制中恢复的结果。(c)2006 Elsevier B. V.保留所有权利。
A CANI/canI Delta heterozygous allele that determines loss of heterozygosity (LOH) was used to study recombination in Saccharomyces cerevisiae cells exposed to ultraviolet (UV) light at different points in the cell cycle. With this allele, recombination events can be detected as canavanine-resistant mutations after exposure of cells to UV radiation, since a significant fraction of LOH events appear to arise from recombination between homologous chromosomes. The radiation caused a higher level of LOH in cells that were in the S phase of the cell cycle relative to either cells at other points in the cell cycle or unsynchronized cells. In contrast, the inactivation of nucleotide excision repair abolished the cell cycle-specific induction by UV of LOH. We hypothesize that DNA lesions, if not repaired, were converted into double-strand breaks during stalled replication and these breaks could be repaired through recombination using a non-sister chromatid and probably also the sister chromatid. We argue that LOH may be an outcome used by yeast cells to recover from stalled replication at a lesion. (c) 2006 Elsevier B.V. All rights reserved.