Johnson K L, Tucker J D, Nath J
Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA.
Mutagenesis. 1998 May;13(3):217-27. doi: 10.1093/mutage/13.3.217.
Whole chromosome painting was used to determine whether the use of different sets of paints would influence results obtained from the analysis of human peripheral blood lymphocytes from 27 healthy unexposed subjects. Painting was also used to determine if aberration frequencies are proportional to the size of selected chromosomes in human lymphocytes irradiated in vitro. The in vitro results showed that the frequencies of radiation-induced stable aberrations (i.e. translocations and insertions) in chromosomes 3, 5 and 6 painted in unique colors are proportional to chromosome size. Aberration frequencies in the normal subjects were measured using two different sets of paints, one set for chromosomes 3, 5 and 6 where each chromosome was labeled in a unique color and one set where chromosomes 1, 2 and 4 were painted in a single color. The frequency of aberrations among chromosomes 1-6 in the population as a whole was also found to be proportional to chromosome size. However, some individual subjects had a distribution of damage that was not proportional to chromosome size due to the presence of clones of abnormal cells. Aberration frequencies measured in chromosomes 3, 5 and 6 as a set were highly correlated with those observed in chromosomes 1, 2 and 4 as a set, after adjusting for the different amounts of the genome that were painted. We also determined whether differences exist in the aberration frequencies measured by two scoring systems: the classical method, where reciprocal exchanges are scored as single events, and PAINT, where each break junction is scored as a single event. The two scoring systems gave highly correlated results for translocations and differed by a constant value (PAINT x 0.58 = classical method). Approximately 27% of translocations were observed to be non-reciprocal due to a failure to detect exchanges involving small amounts of material or to a non-reciprocal exchange mechanism. Our results support the hypothesis that cytogenetic evaluations for biodosimetry can be performed with any one or more of the chromosomes studied here and indicate that the aberration frequency measurements are independent of the scoring system selected for the evaluation. We also present a simple statistical method for identifying subjects that may possess clonal aberrations.
全染色体涂染用于确定使用不同的涂染剂组是否会影响从27名未接触辐射的健康受试者的外周血淋巴细胞分析中获得的结果。涂染还用于确定体外照射的人类淋巴细胞中畸变频率是否与所选染色体的大小成比例。体外实验结果表明，用独特颜色涂染的3号、5号和6号染色体中辐射诱导的稳定畸变（即易位和插入）频率与染色体大小成比例。使用两组不同的涂染剂测量正常受试者的畸变频率，一组用于3号、5号和6号染色体，每条染色体用独特颜色标记，另一组用于1号、2号和4号染色体，用单一颜色涂染。还发现，总体人群中1 - 6号染色体的畸变频率也与染色体大小成比例。然而，由于存在异常细胞克隆，一些个体受试者的损伤分布与染色体大小不成比例。在调整涂染的基因组不同量之后，将3号、5号和6号染色体作为一组测量的畸变频率与1号、2号和4号染色体作为一组观察到的畸变频率高度相关。我们还确定了两种评分系统测量的畸变频率是否存在差异：经典方法，将相互易位计为单个事件；PAINT方法，将每个断裂点计为单个事件。两种评分系统对易位的结果高度相关，且相差一个常数（PAINT×0.58 = 经典方法）。由于未能检测到涉及少量物质的交换或由于非相互交换机制，约27%的易位被观察到是非相互的。我们的结果支持这样的假设，即生物剂量测定的细胞遗传学评估可以用这里研究的任何一条或多条染色体进行，并且表明畸变频率测量与为评估选择的评分系统无关。我们还提出了一种简单的统计方法来识别可能具有克隆畸变的受试者。
