van Rensburg E J, Louw W K, van der Merwe K J
Institute for Life Sciences, University of Pretoria, South Africa.
Int J Radiat Biol Relat Stud Phys Chem Med. 1987 Nov;52(5):693-703. doi: 10.1080/09553008714552211.
Enriched human B-lymphocyte and T-lymphocyte subpopulations were isolated by means of two Percoll density gradient centrifugation steps. Strand-break repair kinetics of 60Co gamma-irradiation-damaged DNA were obtained by applying a modified nucleoid sedimentation technique. Although no variations in the strand-break repair patterns of B-cells and T-cells within an individual could be detected, variations between individuals were evident. Changes in DNA supercoiling during the repair process were studied by means of ethidium bromide intercalation. The supercoiled conformation of DNA in peripheral lymphocyte subpopulations displayed similar undulating patterns within an individual, variations occurring between individuals. The results of this study indicate that alterations to the higher-order structure (supercoiling) of DNA are integral to the repair process.
通过两个Percoll密度梯度离心步骤分离出富集的人B淋巴细胞和T淋巴细胞亚群。应用改良的核仁沉降技术获得了60Coγ射线照射损伤DNA的链断裂修复动力学。尽管在个体内未检测到B细胞和T细胞的链断裂修复模式存在差异，但个体之间的差异是明显的。通过溴化乙锭插入法研究了修复过程中DNA超螺旋的变化。外周淋巴细胞亚群中DNA的超螺旋构象在个体内呈现出相似的波动模式，个体之间存在差异。本研究结果表明，DNA高阶结构（超螺旋）的改变是修复过程不可或缺的一部分。
