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

本研究的目的是：确定和开发特定人类种族的DNA水平的标志物;使用这些标志物进行人群遗传分析;并评估这些标志物在法医学中的有用性。在这项研究中，我们集中在使用短串联重复序列（STR），这是高度多态性，可以使用聚合酶链反应（PCR），一种技术，特别是在检查非常少量的样品，可在法医学检测。首先，通过DNA克隆和DNA数据库（Gen Bank）的搜索来鉴定多态性STR。DNA克隆产生3个含有STR的克隆（TG二核苷酸重复）。然而，在重复次数中未观察到个体间变异。通过对基因数据库（Gen Bank）的检索，进一步确定了8个STR。对于日本人群中STR多态性发生率数据可用的基因组区域，我们比较了不同种族间多态性等位基因的发生率。STR多态性等位基因的发生率在不同种族间呈现特征性差异。等位基因发生率在各种族中的分布模式可分为四种类型。目前还不能直接利用STR多态性作为人种的标记。通过增加研究的基因组区域、种族和人群的数量，积累更多关于STR多态性的基础数据似乎是可取的。根据这些数据，我们可以建立一种方法，将该标记物应用于法医学。

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.