Development of Race-Specific DNA Markers and Their Application to Forensic Medicine

这项研究的目的是：在DNA水平上识别和开发特定人类种族的标记；使用这些标记对人群进行遗传分析；并评估这些标记在法医学中的有用性。在这项研究中，我们专注于短串联重复序列(STR)的使用，这种重复序列具有高度多态，可以通过聚合酶链式反应(PCR)检测到，这是一种在法医学中检测极少量样本时特别有用的技术。首先，通过DNA克隆和搜索DNA数据库(Gen Bank)来鉴定多态STR。DNA克隆得到3个含有TG二核苷酸重复序列的STR克隆。然而，在重复次数上没有发现个体间的差异。通过搜索DNA数据库(Gen Bank)，我们可以进一步识别8个STR。对于基因组中关于日本人STR多态发生率的数据，我们比较了不同种族之间多态等位基因的发生率。不同小种间的STR多态等位基因频率有明显的差异。等位基因在各小种中的分布规律可分为四种类型。目前，还不能直接用STR多态作为种族标记。通过增加研究的基因组区域、小种和种群的数量，积累更多关于STR多态的基本数据似乎是可取的。在此基础上，我们可以建立一种将该标记应用于法医学的方法。

The purposes of this study were ; to identify and develop markers specific to particular human races at the level of DNA : to carry out genetic analysis of populations using these markers : and to assess the usefulness of these markers in forensic medicine. In this study, we concentrated on the use of the short tandem repeats (STR) which are highly polymorphic and which can be detected using the polymerase chain reaction (PCR) , a technique particularly useful in examining the very small amounts of sample that are available in forensic medicine. First, polymorphic STR were identified by DNA cloning and a search of a DNA database (Gen Bank). DNA cloning yielded 3 STR containing clones (TG dinucleotide repeats). However, no inter-individual variation was seen in the number of repeats. A search of a DNA database(Gen Bank)allowed us to identify a further 8 STR.For those areas of the genome for which data concerning the incidence of STR polymorphism among the Japanese people was available, we compared the incidence of polymorphic alleles among different races. The STR polymorphic allele incidence tended to show characteristic differences among different races. The pattern of the distribution of allele incidence in individual races could be divided into four types. At present, it is not possible to directly use STR polymorphisms as marker of race. It seems desirable to accumulate more basic data about STR polymorphisms, by increasing the number of genomic regions, races and populations studied. On the basis of such data, we may establish a method for applying this marker to forensic medicine.