Analysis Of Genetic Polymorphism And Relationship Of 23 Autosomal STR Loci In Guizhou Tujia And Gelao Population

Objective: To investigate the genetic polymorphism of 23 autosomal STR loci in Guizhou Gelao and Tujia populations,to evaluate the application value of Huaxia PlatinumTM kit in forensic medicine,and to provide data support for paternity identification and individual identification in Guizhou Gelao and Tujia populations.In order to provide genetic data support for the historical origin,migration and gene fusion of Guizhou Tujia and Gelao populations,the genetic relationships between Tujia and Gelao populations and other 22 different geographical,ethnic and language populations are analyzed.Methods:(1)Sample collection: 480 and 490 unrelated healthy individuals from Guizhou Tujia and Gelao ethnic group were collected.(2)STR typing: First PCR amplification was performed with Huaxia PlatinumTM kit,then capillary electrophoresis was performed on an automated analyzer,and finally allelic typing results were obtained.(3)Polymorphism data and forensic parameters: allele frequencies and forensic parameters of 23 STR loci were calculated,and Hardy-Weinberg equilibrium and linkage disequilibrium(LD)of this population were tested.(4)Population genetic relationship analysis: 21 reference populations were selected according to geographical,ethnic and linguistic factors.Based on the 23 common STR loci among all populations,Nei’s genetic distance of the 23 populations was calculated,and visual heat map and cluster analysis were performed.Then phylogenetic tree(N-J tree),principal component analysis(PCA)and multidimensional scaling analysis(MDS)were constructed.Results:(1)A total of 264 alleles were detected in 480 Guizhou Tujia unrelated individuals,with the number of alleles in each locus ranging from 6 to 20 and gene frequencies ranging from 0.0004 to 0.5104.The heterozygosity(Ho)was 0.6250(TPOX)~ 0.9271(Penta E),the polymorphism information content(PIC)was 0.5666(TPOX)~ 0.9071(Penta E),and the personal identification rate(DP)was 0.8043(TPOX)~ 0.9837(Penta)E),non-paternal exclusion probability(PE)is 0.3220(TPOX)~ 0.8510(Penta E),matching probability(MP)was 0.0163(Penta E)~ 0.1957(TPOX),and typical paternity index(TPI)was 1.3333(TPOX)~ 6.8571(Penta)E).(2)A total of 264 alleles were detected in 490 Guizhou Gelao unrelated individuals.The number of alleles ranged from 5 to 21 in each locus,and the gene frequencies ranged from 0.0010 to 0.5255.The heterozygosity(Ho)was 0.6020(TPOX)~ 0.9122(Penta E),polymorphism information content(PIC)was 0.5627(TPOX)~ 0.9129(Penta E),and personal identification rate(DP)was 0.7939(TPOX)~ 0.9862(Penta E),non-paternal exclusion probability(PE)was 0.2933(TPOX)~ 0.8205(Penta E),matching probability(MP)was 0.0138(Penta E)~ 0.2061(TPOX),and typical paternity index(TPI)was 564(TPOX)~ 5.6977(Penta)E).(3)The results of population genetic relationship analysis:(1)Nei’s genetic distance showed that the genetic distance between Guizhou Tujia population and US African American was the largest(Rst=0.1377),and that between Guizhou Tujia and Indian was the smallest(Rst=0.0861).The genetic distance between Guizhou Tujia and Xinjiang Kyrgyz was the largest(Rst=0.0491),and the genetic distance between Guizhou Tujia and Guizhou Han was the smallest(Rst=0.0042).The genetic distance between Guizhou Gelao of Guizhou and US African American is the largest(Rst=0.1609)and that between Guizhou Gela and Indian is the smallest(Rst=0.1048).The genetic distance from Xinjiang Kyrgyz was the largest(Rst=0.0727),and from Guizhou Han was the smallest(Rst=0.0278).The genetic distance between Han populations except Sichuan Han group was small(Rst<0.0196).(2)Heat map and cluster analysis showed that Guizhou Tujia and Gelao populations were close to that of Guizhou Han,Guizhou Miao,Shanxi Han,Shaanxi Han,Shandong Han,Liaoning Han and Hunan Han populations.The genetic distance between the Tibetan,Yi and Han populations in Sichuan,Kyrgy,Kazakh and Uyghur populations in Xinjiang is relatively long and there is a large genetic distance between them and foreign populations.(3)From the phylogenetic tree,it can be seen that Guizhou Tuji and Guizhou Gelao populations clustered first,then clustered with Hubei Tujia,then clustered with Han populations in different areas,Guizhou Miao and Sichuan populations,and finally clustered with Xinjiang populations and foreign populations.(4)The 23 groups are divided into three main groups in PCA.Guizhou Tujia and Guizhou Gelao,together with Guizhou Miao,Guizhou Han and various ethnic minorities and Han are clustered in the lower right of PCA figure.(5)The MDS results show that both Guizhou Tujia and Guizhou Gelao populations are distributed in the fourth quadrant,the Han populations from different regions are clustered between Guizhou Tujia and Guizhou Gelao populations,the Tibetan populations from Sichuan province are clustered closely,and the Indo-European language populations from abroad are dispersed in the second and third quadrant.Conclusion:(1)In this study,the Huaxia PlatinumTM kit was used for the first time to investigate the genetic polymorphism of Guizhou Tujia and Gelao populations.The results showed that 23 autosomal STR loci have high polymorphism and individual recognition ability in Guizhou Tujia and Gelao populations,which has important application value in forensic medicine.(2)The genetic relationship between Guizhou Tujia and Guizhou Han people and Hubei Tujia populations is closer than other populations.(3)The analysis of population genetic relationship shows that populations with common ethnic and language origins and close geographical locations show more intimate genetic relationship.It reflects the influence of geographical,ethnic and linguistic factors on genetic structure from the perspective of genetics,and enriches the knowledge system of genetic history of different populations in China.