Study of Genetic effects of A-bomb radiation using microarray CGH

研究原子弹辐射对人体的遗传效应，即原子弹辐射对人体生殖细胞的影响，对制定辐射防护标准和其他目的具有重要意义。因此，我们向实验室介绍了微阵列CGH方法，这是研究上述问题最有效的技术之一。在该项目中，我们已经完成了阵列CGH有效使用的基本要求：(1)建立准确检测大缺失的实验条件；(2)通过计算机图像分析快速识别基因组拷贝数的增加或减少；(3)开发和改进计算机软件，用于管理大量数据。因此，很明显，利用微阵列技术，我们的实验室已经对其进行了改进，辐射引起的缺失型变异可以快速、更可靠地识别到100万个碱基对（1 Mb）或更多。我们以120万碱基对（1.2 Mb）的间隔选择了2400个位于常染色体上的Bac克隆，并将其打印在3个玻片上。利用微阵列，我们对从30名原子弹幸存者儿童和30名对照组儿童中获得的基因组DNA进行了群体研究，并在两个个体中发现了两种不同类型的变异。一项对这些个体父母的研究表明，这些变异至少遗传自父母中的一方。除了群体研究外，我们还使用该阵列分析了辐射暴露细胞的基因组，并在几个位点发现了缺失型变异。以此为模型，我们建立了利用定量PCR和定量Southern分析确定变异位点大小的实验条件。因此，有可能在人口研究过程中迅速确定变异的特征。通过使用现有技术对扩大的研究人群进行分析，现在有可能首次阐明辐射对人类的跨代效应（遗传效应），这在以前只可能在动物模型中实现。少

Studying the genetic effects of A-bomb radiation in humans, i.e., he effects of A-bomb radiation on human germ cells, is very important for the establishment of radiation protection standards and for other purposes. We therefore introduced to our laboratory a microarray CGH method, one of the most effective techniques for studying the above. In the research supported by the Grant-in-Aid, we have completed work for satisfying basic requirements in the effective use of array CGH : (1)establishment of experiment conditions for accurately detecting large deletions, (2)expedited identification of increased or decreased genome copy numbers by means of computer image analyses, and (3)development ant improvement of computer software for management of voluminous data. Thus, it has become clear that, with the microarray technique, for which improvements have been made at our laboratory, radiation-induced deletion-type variations as large as noe million base pairs (1 Mb) or more can be quickly an … More d reliably identified. We selected about 2,400 Bac clones located on autosomes at an interval of 1.2 million base pairs (1.2 Mb), and printed them on three glass slides. Using the microarray, we conducted a population study for genome DNA obtained from 30 children of A-bomb survivors and 30 children of the control group, and identified two different types of variants in two individuals. A study of these individuals' parents showed that these variants were inherited from at least one of the parents. Apart from the population study, we analyzed the genomes from radiation-exposed cells using the array, and identified deletion-type variants in several sites. Using the above as a model, we established experiment conditions for determining the size of variant sites using quantitative PCR and quantitative Southern analysis. Thus, it was possible to speedily characterize the variants identified in the process of the population study. By conducting analysis using the current technique on an expanded study population, it is now possible to, for the first time, clarify transgenerational effects (genetic effects) of radiation in humans, whih had previously been possible only in animal models. Less