INCORPORATED BROMODEOXYURIDINE ENHANCES THE SISTER-CHROMATID EXCHANGE AND CHROMOSOMAL ABERRATION FREQUENCIES IN AN EMS-SENSITIVE CHINESE-HAMSTER CELL-LINE
INCORPORATED BROMODEOXYURIDINE ENHANCES THE SISTER-CHROMATID EXCHANGE AND CHROMOSOMAL ABERRATION FREQUENCIES IN AN EMS-SENSITIVE CHINESE-HAMSTER CELL-LINE
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DOI：
10.1016/0027-5107(86)90090-4
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发表时间：
1986-09-01
期刊：
影响因子：
--
通讯作者：
THOMPSON, LH
中科院分区：
文献类型：
--
作者：
CARRANO, AV;MINKLER, JL;THOMPSON, LH
突变中国仓鼠细胞系EM9的特征在于高基线姐妹染色单体交换（SCE）频率、对细胞杀伤的敏感性增加以及DNA链断裂修复缺陷。这种多养型表型的分子基础尚不清楚。我们研究了，在染色体水平上，这种突变体的敏感性增加，纳入BrdUrd。通过改变模板DNA中BrdUrd的量并测量SCE和染色体畸变的频率，我们证明了EM 9对模板DNA链中存在的BrdUrd的敏感性增强。我们的研究结果表明，6倍增加SCE发生由于DNA复制超过BrdUrd取代的模板相对于dThd取代的模板。关于EM9中的畸变产生，模板链中具有BrdUrd的染色单体的畸变显著增强并且对损伤具有特异性偏好。虽然这些细胞与布卢姆氏综合征患者的细胞具有某些表型特征，但基因型相似性尚未确定。
The mutant Chinese hamster cell line, EM9, is characterized by a high baseline sister-chromatid exchange (SCE) frequency, increased sensitivity to cell killing, and a defect in DNA strand-break repair. The molecular basis for this pleotrophic phenotype is not known. We examined, at the chromosomal level, the increased sensitivity of this mutant to incorporated BrdUrd. By varying the amount of BrdUrd in template DNA and measuring the frequency of SCEs and chromosomal aberrations, we demonstrated the enhanced sensitivity of EM9 to BrdUrd present in the template strand of DNA. Our results show that a 6-fold increase in SCEs occurs due to DNA replication over a BrdUrd-substituted template relative to a dThd-substituted template. With regard to aberration production in EM9, there is a significant enhancement of aberrations and a specific bias toward damage for the chromatid with BrdUrd in the template strand. While these cells share some phenotypic properties with cells from patients with Bloom''s syndrome, the genotypic similarities have not yet been established.