Genetic polymorphisms and genetic relationship of 24 autosomal STR loci in Gelao and Miao population of Guizhou / 解放军医学杂志

Objective: To investigate the genetic polymorphisms of 24 autosomal short tandem repeats (STR) loci in Gelao and Miao populations dwelled in Guizhou province, and explore the population genetic relationships and evaluate their application value on forensic medicine. Methods: The DNA samples of 732 unrelated individuals (399 Guizhou Gelao population and 333 Guizhou Miao population) were amplified using SureID® PanGlobal kit, and the PCR products were analyzed by electrophoresis through 3500XL genetic analyzer. The fragment sizes of alleles were subsequently analyzed by GeneMapper ID-X v1.5. Allele frequencies and forensic genetic parameters of 24 STR loci were statistically analyzed and compared with the available data of other populations from different races and regions. Results: For Guizhou Gelao and Miao populations, the individual discrimination power (DP) ranged from 0.7833 to 0.9909 and 0.8010 to 0.9909, respectively; the polymorphic information content (PIC) ranged from 0.5608 to 0.9385 and 0.5677 to 0.9414, respectively; the total discrimination power (TDP) were 1-7.6036 × 10-30 and 1-6.8630 × 10-30, respectively, and the cumulative probability of exclusion (CPE) were 1-1.9608 × 10-11 and 1-1.9738 × 10-14, respectively. Analysis with the matrix of Nei's DA genetic distance indicated that the genetic distance was the smallest (0.0205) between Guizhou Gelao and Hubei Han populations, while was the largest (0.0449) between Guizhou Gelao and Yunnan Miao populations; the genetic distance was minimum (0.0033) between Guizhou Miao and Hunan Han populations, while was maximal (0.0363) between Guizhou Miao and Yunnan Miao. Conclusions: The 24 STR loci are abundant in genetic polymorphism in Guizhou Gelao and Miao populations. It is of great significance to study the genetic diversity of different ethnic groups in order to understand their origin, migration and interrelationship.

Genetic Polymorphisms of 27 Y-STR Loci in Dongxiang Population of Gansu Province / 法医学杂志

OBJECTIVES@#To investigate the genetic polymorphisms of 27 Y-STR in Dongxiang population of Gansu province, and to explore the population genetic relationship and the value of forensic application.@*METHODS@#The genotyping of 27 Y-STR loci in 526 unrelated male individuals in Dongxiang population of Gansu province were detected by STRtyper-27Y kit. The allele frequencies and haplotype diversity were also calculated. Combining with other genetics data of 14 loci in same populations, which have been published at home and abroad, the genetic distance and clustering relationship in Dongxiang population of Gansu province were calculated.@*RESULTS@#Totally 55 haplotypes were found in the DYS385a/b biallelic loci, 39 haplotypes in DYF387S1 loci, and 4-16 alleles in the rest 23 single copy STR loci. The GD value was from 0.453 9 （DYS391） to 0.957 5 （DYS385a/b）. Totally 471 haplotypes were observed in 27 Y-STR loci in 526 individuals, and the value of haplotypes diversity was 0.999 5. The genetic distance between Dongxiang and Tibetan populations of Gansu province was the closest （0.068 2）, while it was the longest between Dongxiang population in Gansu province and Han population in Henan province （0.084 7）. The result of dimensional analysis established upon the genetic distance was basically matched with that of the cluster analysis.@*CONCLUSIONS@#The 27 Y-STR loci show a high genetic polymorphism in Dongxiang population of Gansu province, which has significance for the Y-STR database establishment, population genetics study and forensic practice.

Genetic polymorphisms of 19 X-STR loci for forensic application in China’s three ethnicities / 基础医学与临床

Objective To investigate the genetic data of the 19 X-STR loci in three ethnicities of China ( Han, Gelao,Miao) and to evaluate the application in forensic science.Methods The DNA samples of unrelated individ-ual in Han (n=308), Gelao (n=398), Miao (n=323) ethnicities were amplified using MicroreaderTM19X ID System kit, and the PCR products were analyzed by electrophoresis through 3500XL genetic analyzer. The fragment sizes of alleles were taken subsequently by GeneMapper? ID-X. Allele frequencies and national genetics parameters of the 19 X-STR were analyzed by statistics. The allele frequencies were compared among the three nationalities and were compared with available data of other Han ethnicities from different regions. Results After the Bonferroni correction at a 95% significance level, no significant departures from the Hardy-Weinberg equilibrium was observed. Linkage disequilibrium test showed no significant allelic association between all 19 X-STR loci after Bonferroni’s correction. The cumulative discrimination power in females and in males were greater than 0.999 999 999 99 and 0.999 999 999 94,respectively. The combined power of exclusion in trios and in duos were greater than 0.999 999 999 36 and 0.999 999 52,respectively. The p values,calculated throuth Arle-quin v3.5 software,there were significantly different as detected at loci of X-STR among the different nationalities. Conclusions This panel of X-STR is highly polymorphic in China’s three ethnicities and can be served as a supple-mentary to the current STR system for individual identification.

Establishment and Verification of 6-color Fluorescent-labeled Rapid PCR Amplification System / 法医学杂志

OBJECTIVE@#To establish the rapid PCR amplification program and system and to verify the technical indexes.@*METHODS@#PCR multiplex and capillary electrophoresis detection of 24 autosomal STR loci and one Y-STR loci using the 6-color fluorescence marking technology, as well as A melogenin and Y-InDel. Meanwhile, sensitivity, specificity, identity, stability, mixing and a batch of sample tests were investigated, and the genotype of various routine samples and degraded, exfoliated cell samples were observed.@*RESULTS@#The sensitivity of the system was 0.062 5 ng. In addition, the genotype could be detected accurately only around 65 min via rapid amplification. The species-specificity was high and the genotyping of all kinds of dry blood specimens of filter paper and mixed, degraded, exfoliated cell samples were accurate.@*CONCLUSION@#The rapid amplification system can significantly improve the detection rate, and obtain accurate and stable genotyping results, which may be important implications for the establishment of STR database and study on population genetics and forensic identification.

Forensic Application of 16 X-STR Loci in Henan Han Population / 法医学杂志

OBJECTIVES@#To investigate the genetic data of 16 X-STR loci in Henan Han population and to assess the application value in forensic science.@*METHODS@#The DNA of 326 unrelated individuals in Henan Han population were amplified using Goldeneye™ DNA identification system 17X kit, and the PCR products were analyzed by electrophoresis through 3130xl genetic analyzer. The fragment sizes of alleles were analyzed subsequently by GeneMapper® ID-X. Allele frequencies and population genetics parameters of 16 X-STR loci were analyzed statistically and compared with the available data of other Han populations from different regions.@*RESULTS@#Among the 16 X-STR loci, DXS6800 were found to be moderately polymorphic and the other 15 X-STR loci were highly polymorphic. The cumulative discrimination power in females and males were 0.999 999 999 999 992 and 0.999 999 996 577 712, respectively. The combined power of exclusion in trios and in duos were 0.999 999 971 and 0.999 992 574, respectively.@*CONCLUSIONS@#The 16 X-STR loci meet the application requires of forensic genetics, especially for testing the special paternity cases.