The Detection Of17Y-STRs And Their Applications To The Evolution Of Human Origin

PurposeY-STR is a series of short tandem repeat sequences on the Y chromosome. As having the characteristics of non-recombination, monomer and paternal inheritance, Y chromosome has become an important marker for genetic diversity research, which is widely used in the individual recognition, paternity identification, gene mapping, population genetics and ethnology research. The study of human origin, evolution and migration based on Y-STR data is very popular in both domestic and foreign researches. As a nation with a long history, Mongolians have lived in the grasslands of northern China since ancient times. However, the research of using Y-STR to speculate Mongolian origin and evolution is rare. Our study is based on male Mongolian Y-STR to study the Mongolian population polymorphisms and it is particularly important to study its relationship with other populations. We collected Y-STR loci frequency data from different provinces and different nationalities, and calculated the genetic distance of all different groups, and then built a phylogenetic tree among different nationalities and different regions. Our aim is to explore the genetic relationships among these Chinese nationalities.MethodsDNA was extracted using the phenol-chloroform method from125male Mongolian. PCR for Y-STR loci was performed in fluorescence-based multiplex reaction by using the AmpFISTR Y-FilerTM kit and a made-in-China GoldeneyeTM20Y kit respectively. Capillary electrophoresis was performed in an ABI Prism3130XL Genetic Analyzer. Electrophoresis data was analyzed by ABI GeneMapper ID software V3.2. Then we obtained the17Y-STR gene typing data in125unrelated healthy males from Inner Mongolia Autonomous Region.Other frequency data of the17Y-STR loci of different provinces and different nationalities was collected through public database or peer-reviewed journals such as CNKI, Pubmed, and so on. The gene frequencies of17Y-STR loci commonly used in forensic medicine(DYS19, DYS385a/b, DYS389I, DYS38II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, Y-GATA-H4) was collected from33groups in China after several screening. The genetic distance among all groups was calculated by phylip3.69statistical package, and a phylogenetic tree was built by using the Neighbor-joining method. Then we analyzed the genetic polymorphisms of all samples.The resultsThe17Y-STR loci in125healthy unrelated male Mongolian were detected. There were114haplotypes in125cases of samples, of which106haplotypes were observed for only one time,3haplotypes were observed for three times and2haplotype were observed for5times. DYS19, DYS389I, DYS38II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635and Y-GATA-H4were detected to have5,3,7,8,4,7,5,4,5,5,6,6,7,8,5alleles, DYS385a/b to have42haplotypes, respectively. The GD value was0.7321,0.5907,0.7286,0.7083,0.6053,0.7350,0.6822,0.4781,0.5059,0.7474,0.7627,0.6115,0.7863,0.7708,0.6396and0.7708. DYS437GD value was the lowest to be0.4781, while DYS385a/b GD value was the maximum to be0.964. Except DYS437, other GD values were greater than0.5. The results showed that the17Y-STR loci had good polymorphisms in Mongolian population from Inner Mongolia Autonomous Region and was suitable for forensic applications.We compared the entire17Y-STR loci gene frequency data among33ethnic groups and then calculated their genetic distance. Neighbor-joining method was used to build phylogenetic tree according to the genetic distance. We got interesting results based on our calculation. On the lower part of the phylogenetic tree, the genetic distance of Taiwanese Atayal and Paiwan tribe are near, and then they got together with Taiwan Han nationality. She in Fujian, Han in Fujian, Han in Chengdu and Han in Zhejiang got together with each other. Nine minority ethnic groups of Guangxi come together with respectively in turn. After the aggregation of Zhejiang Han and Guangxi minorities, the southern groups join in. Han in Taiyuan and Han in Beijing are close, joined with the Lanzhou Hans and Henan Hans. Mongolia Han and Shandong Han got together in turn. Mongolians, which was detected in our first part of this paper, is relatively close with Xinjiang Kazak in genetic distance. And Hunan Hans, Yunnan Bais, Yunnan Was are in a transition zone between the southern and northern Chinese.Conclusion1.17Y-STR loci were detected in125unrelated men from Inner Mongolia Autonomous Region, and the result showed that17Y-STR loci has a good polymorphic distribution in the Mongolian population, which is suitable for forensic applications. Our results will not only provide data support for Y-STR DNA database, paternity identification and forensic individual identification in forensic science, but also provide an important theoretical basis for the study of the ethnic genetic polymorphism, analysis of human origin, evolution, population genetic relationship.2. There were significant differences in the genetic polymorphism between the Hans and the minority ethnic groups in China. The Han nationality between the southern and the northern China also has certain genetic distance. Mongolian of Inner Mongolia Autonomous Region is relatively close with Xinjiang Kazak in genetic distance. Tibetans showed to be an independant class.