RHD Gene Analysis of A Blood Donor with Del Phenotype / 中国实验血液学杂志

OBJECTIVE@#To analyze the RHD genotype of a blood donor with Del phenotype in Yunnan.@*METHODS@#Rh serological phenotype was identified. RHD gene was detected by PCR-SSP typing, and its 10 exons were sequenced. Exon 9 was amplified for sequencing and analysis. RHD zygosity was detected.@*RESULTS@#The Rh phenotype of this specimen was CcDelee. Genomic DNA exhibited a 1 003 bp deletion spanning from intron 8, across exon 9 into intron 9. The deletion breakpoints occurred between two 7-bp short tandem repeat sequences. There was no variation in the sequences of the remaining exons. The Rh hybridization box test showed that there was one RHD negative allele.@*CONCLUSION@#This specimen is Del type caused by deletion of RHD exon 9.

Comparative of Forensic DNA Identification Using Cell Lysis Method and Magnetic Beads Method / 法医学杂志

OBJECTIVES@#To compare the effects of cell lysis method and magnetic beads method in forensic DNA identification and to explore these two methods in forensic DNA identification.@*METHODS@#The genome DNA of THP-1 cells in different quantities was extracted by the cell lysis method and magnetic beads method, and the DNA content was quantified by real-time quantitative PCR. The cell lysis method and magnetic beads method were used to type the STR of human blood with different dilution ratios.@*RESULTS@#When the numbers of THP-1 cell were 100, 400 and 800, the DNA content extracted by cell lysis method were (1.219±0.334), (5.081±0.335), (9.332±0.318) ng, respectively; and the DNA content extracted by magnetic beads method were (1.020±0.281), (3.634±0.482), (7.896±0.759) ng, respectively. When the numbers of THP-1 cells were 400 and 800, the DNA content extracted by the cell lysis method was higher than that by the magnetic beads method. The sensitivity of cell lysis method and magnetic beads method was similar in STR typing of human blood at different dilution ratios. Complete STR typing could be obtained at 100, 300 and 500-fold dilutions of blood samples, but could not be detected at 700-fold dilution. STR typing of undiluted human blood could not be detected by cell lysis method.@*CONCLUSIONS@#The cell lysis method is easy to operate and can retain template DNA to the maximum extend. It is expected to be suitable for trace blood evidence tests.

Genetic Polymorphism of 16 X-STR Loci in Xinjiang Uygur Population / 法医学杂志

OBJECTIVES@#To study the genetic polymorphism and population genetic parameters of 16 X-STR loci in Xinjiang Uygur population.@*METHODS@#The Goldeneye® DNA identification system 17X was used to amplify 16 X-STR loci in 502 unrelated individuals (251 females and 251 males). The amplified products were detected by 3130xl genetic analyzer. Allele frequencies and population genetic parameters were analyzed statistically. The genetic distances between Uygur and other 8 populations were calculated. Multidimensional scaling and phylogenetic tree were constructed based on genetic distance.@*RESULTS@#In the 16 X-STR loci, a total of 67 alleles were detected in 502 Xinjiang Uygur unrelated individuals. The allele frequencies ranged from 0.001 3 to 0.572 4. PIC ranged from 0.568 8 to 0.855 3. The cumulative discrimination power in females and males were 0.999 999 999 999 999 and 0.999 999 999 743 071, respectively. The cumulative mean paternity exclusion chance in trios and in duos were 0.999 999 997 791 859 and 0.999 998 989 000 730, respectively. The genetic distance between Uygur population and Kazakh population was closer, and the genetic distance between Uygur and Han population was farther.@*CONCLUSIONS@#The 16 X-STR loci are highly polymorphic and suitable for identification in Uygur population, which can provide a powerful supplement for the study of individual identification, paternity identification and population genetics.

Application Progress of Massively Parallel Sequencing Technology in STR Genetic Marker Detection / 法医学杂志

In recent years, more and more forensic genetics laboratories have begun to apply massively parallel sequencing (MPS) technology, that is, next-generation sequencing (NGS) technology, to detect common forensic genetic markers, including short tandem repeat (STR), single nucleotide polymorphism (SNP), the control region or whole genome of mitochondrial DNA (mtDNA), as well as messenger RNA (mRNA), etc., for forensic practice, such as individual identification, kinship analysis, ancestry inference and body fluid identification. As the most widely used genetic marker in forensic genetics, STR is currently mainly detected by capillary electrophoresis (CE) platform. Compared with CE platform, MPS technology has the advantages of simultaneous detection of a large number of genetic markers, massively parallel detection of samples, the polymorphism of sequence detected by NGS makes STR have the advantages of higher resolution and system efficiency. However, MPS technology is expensive, there is no uniform standard so far, and there are problems such as how to integrate MPS-STR data with the existing CE-STR database. This review summarizes the current status of the application of MPS technology in the detection of STR genetic markers in forensic genetics, puts forward the main problems that need to be solved urgently, and prospects the application prospect of this technology in forensic genetics.

Establishment of Multiplex Amplification System of STR Loci in Felis Catus and Its Forensic Application / 法医学杂志

OBJECTIVES@#To construct a Felis catus STR loci multiplex amplification system and to evaluate its application value by testing the technical performance.@*METHODS@#The published Felis catus STR loci data were reviewed and analyzed to select the STR loci and sex identification loci that could be used for Felis catus individual identification and genetic identification. The fluorescent labeling primers were designed to construct the multiplex amplification system. The system was validated for sensitivity, accuracy, balance, stability, species specificity, tissue identity and mixture analysis, and investigated the genetic polymorphisms in 145 unrelated Felis catus samples.@*RESULTS@#Sixteen Felis catus autosomal STR loci and one sex determining region of Y (SRY) were successfully selected, and constructed a multiplex amplification system containing the above loci. The complete profile of all alleles could still be obtained when the amount of DNA template was as low as 0.25 ng. There was no specific amplification peak in other common animal samples. Population genetic surveys showed that total discrimination power (TDP) of the 16 STR loci was 1-3.57×10-20, the cumulative probability of exclusion (CPE) was 1-6.35×10-5 and the cumulative probability of matching was 3.61×10-20.@*CONCLUSIONS@#The Felis catus STR multiplex amplification system constructed in this study is highly sensitive, species-specific, and accurate in typing results, which can provide an effective solution for Felis catus species identification, individual identification and kinship identification in the field of forensic science.

Bibliometric Analysis of Forensic Genetics Literatures in SCIE from 1989 to 2019 / 法医学杂志

Objective To conduct bibliometric analysis of forensic genetics literatures published by Chinese mainland scholars in SCIE journals from 1989 to 2019, to show the research achievements of the past three decades and predict future research fields and directions. Methods Microsoft Office Excel 2019 was utilized to analyze the general situation, research institutions, authors, funds, author keywords, etc. of the literatures. The status of research in forensic genetics in Chinese mainland was visualized by PlotDB, Gephi 0.9.2 software and literature interpretation. Results During the last three decades, 1 126 forensic genetics literatures were published by scholars from Chinese mainland on SCIE journals, mostly articles. The quantity and quality of the literatures were both on the increase. The number of literatures published in Forensic Science International-Genetics was the highest, and 60.83% of the literatures were funded, mainly by the National Natural Science Foundation of China （498 literatures）. The current research hotspots were STR, SNP, InDel polymorphisms, linkage genetic markers, mtDNA genetic markers, epigenetic markers, RNA genetic markers, chip technology and omics research method. Conclusion The forensic genetics in China has developed rapidly along with the promotion of forensic science in universities. The SCIE literatures on forensic genetics published by Chinese mainland scholars increased rapidly with the funding from the National Natural Science Foundation of China and Ministry of Science and Technology of the People's Republic of China, which positively contributes to the development of basic research and the improvement of overall level in forensic genetics in China.

Application of ITO Method in Determination of Special Half-Sibling Relationship / 法医学杂志

OBJECTIVES@#To identify whether the relationship between Zhang A, Zhang B, Zhang C and Zhang X is the half-sibling relationship whose mother is sister (hereinafter referred to as the special half-sibling relationship) or the common first cousin relationship and discuss the application of ITO method in discriminating the special kinship.@*METHODS@#DNA was extracted from blood stain of four identified individuals, PowerPlex® 21 System and AGCU 21+1 STR kit were used to detect autosomal STR genetic markers. Investigator® Argus X-12 QS kit was used to detect the X chromosome STR genetic markers, the special half-sibling index (SHSI) and first cousin index (FCI) and their likelihood ratio (LR) were calculated by ITO method.@*RESULTS@#The LR results of SHSI to FCI, which were calculated based on autosomal STR genotyping and the analysis of X-STR genotyping results suggested that the relationship between Zhang A, Zhang B, Zhang C and Zhang X was inclined to be a special half-sibling relationship.@*CONCLUSIONS@#For the identification of special kinship, it is necessary to comprehensively apply various genetic markers according to the case. After the conclusion that shared alleles cannot be excluded from the analysis, ITO method can be further used to establish discriminant assumptions according to the specific case to obtain objective and reliable identification opinions.

Forensic Application of ForenSeqTM DNA Signature Prep Kit in Zhengjiang She Ethnic Group / 法医学杂志

OBJECTIVES@#To evaluate the ability of the ForenSeqTM DNA Signature Prep kit (ForenSeq kit) in analyzing the sequence information of STRs in Zhejiang She ethnic group and its forensic application efficacy.@*METHODS@#A total of 50 Zhejiang She ethnic group samples were sequenced with the ForenSeq kit on the MiSeq FGx platform. The data was analyzed using ForenSeqTM universal analysis software to obtain the motif structure and flank regions of the 58 STRs, then compared with PCR-CE typing results to test the consistency. At last, the allele frequency and population genetic parameters were calculated.@*RESULTS@#A total of 448 sequence polymorphic alleles were detected in 50 samples of Zhejiang She ethnic group. Compared with fragment length polymorphism detected by PCR-CE, 82 alleles were increased by MPS detection based on ForenSeq kit, and 7 SNPs variation were detected in the flanking regions of 6 loci. The 22 male individuals were genotyped, and total 19 haplotypes were detected in 24 Y chromosome STRs of these 22 males. The cumulative discrimination power of the 27 autosomal STRs was 1-8.87×10-30, the cumulative probability of exclusion of duo-testing was 0.999 999 962 640 657, the cumulative probability of exclusion of trios-testing was 0.999 999 999 999 633.@*CONCLUSIONS@#Based on MPS typing technology, using the ForenSeq kit greatly improves the detection efficiency. In addition, the 58 STRs have good genetic polymorphisms in Zhejiang She ethnic group, which are suitable for individual identification and paternity identification in forensic application.

Development and Forensic Application of EX20+30Y Kit / 法医学杂志

OBJECTIVES@#To develop a multiplex PCR amplification system (EX20+30Y for short) of 19 autosomes, 30 Y-STR loci plus the gender indicator, and evaluate its forensic application value.@*METHODS@#With the six-color fluorescence labeling technology, a multiplex amplification system of 19 autosomal STR loci and 30 Y-STR loci plus the gender indicator was constructed. Blood samples from 210 unrelated individuals, 69 daily case samples and standard samples 9948 and 9947A were collected for loci detection and analysis. The EX20+30Y multiplex amplification system was evaluated by its sensitivity, mixed sample detection ability, species specificity, balance, direct amplification ability, sample applicability and anti-inhibition ability.@*RESULTS@#Multiplex amplification of blood samples from 210 unrelated individuals by the detection system obtained accurate genotyping results. The detection sensitivity of standard samples was 0.125 ng and the species specificity was high. The 69 samples from daily cases were genotyped correctly. Moreover, standard sample 9948 could be accurately genotyped even if the samples contained a certain concentration of inhibitors.@*CONCLUSIONS@#The multiplex amplification system established in this study can conduct combined examination of 19 autosomes, 30 Y-STR loci plus the gender indicator with accurate genotyping and high sensitivity. It has a good forensic application prospect.

Genetic polymorphism of 23 autosomal STR loci in Han population from Yuncheng, Shanxi Province / 中南大学学报(医学版)

OBJECTIVES@#Due to the genetic feature of high diversity than other DNA markers, short tandem repeat (STR) plays key roles in forensic, anthropology, and population genetics. Newly introduced multiple STR kit is more valuable because of the greatly improved discriminatory power with the increase in the number of STR loci. The genetic polymorphic data are essential for the application and research in specific population. This study aims to investigate the genetic polymorphism of Han population residing in Yuncheng district, Shanxi Province, to evaluate the application of 23 STR loci in forensic personal identification and paternity test, and to explore the genetic relationship of Han population between Yuncheng and other populations.@*METHODS@#A total of 23 STR loci were amplified from 525 healthy unrelated individuals from the Han nationality in Yuncheng, Shanxi Province using the AGCU EX25 amplification kit. The products were detected and separated by ABI 3500 Genetic Analyzer. Alleles were genotyped by GeneMapper ID (Version 3.2) software, and corresponding frequencies and forensic parameters were calculated. We calculated the genetic distance and plotted the neighboring-joining tree with other 13 population.@*RESULTS@#The allele frequency of the 23 STRs ranged from 0.0010 to 0.5090. No deviation from Hardy-Weinberg equilibrium (@*CONCLUSIONS@#These 23 STRs are highly genetic polymorphic and informative in the Han population of Yuncheng, Shanxi Province, which can provide basic data for forensic personal identification, paternity testing, and population genetic research.

Genetic Structure Analysis of Y Chromosome STR and SNP in Population of Changshu / 法医学杂志

Objective To provide a theoretical basis for building a Y chromosome database in specific regions by analyzing the pedigree specific core haplogroup and region specific genetic structure in Changshu. Methods One thousand seven hundred and two samples from unrelated Han male individuals in Changshu were collected. Then 27 Y-STR were genotyped through YfilerTM Plus PCR Amplification Kit, Y-SNP haplogroup of each sample was speculated using Y-Predictor software and some samples were verified by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR）. Results A total of 1 556 haplotypes were found on the 27 Y-STR genetic markers of the 1 702 samples. The haplotype diversity （HD） value was 0.999 827. DYS385 （0.933） had the highest gene diversity （GD） value while DYS438 （0.409） had the lowest. By the Y-Predictor software, all samples were confirmed to be from 162 sub-haplogroups of C, D, N, O, Q and R. Samples were randomly selected to verify the prediction results by the software and the prediction accuracy of Y-Predictor software was as high as 95.74%. Conclusion This study found that 27 Y-STR genetic markers have relatively high polymorphisms in the Changshu population, and have good forensic individual identification and paternity testing ability.

Polymorphisms of 19 Autosomal STR Loci in Sichuan Han Population and Their Forensic Application / 法医学杂志

Objective To investigate the allele distribution, population genetics parameters and genetic analysis of neighboring populations of 19 autosomal STR loci in Sichuan Han population, and to evaluate their forensic application value. Methods The Goldeneye?? DNA ID system 20A was used to perform multiplex PCR amplification and allelic gene typing of 19 STR loci in 1 201 unrelated Han individuals from Sichuan Province. Allele frequencies and population genetics parameters were calculated. The Nei's genetic distances between Sichuan Han population and 12 previously reported populations were analyzed. Multidimensional scaling and principal component analysis were carried out and phylogenetic trees were also constructed. Results The heterozygosity of 19 STR loci ranged from 0.617 0 to 0.915 1, their discrimination power ranged from 0.777 4 to 0.986 5, matching probability ranged from 0.013 5 to 0.222 6, polymorphism information content ranged from 0.546 4 to 0.910 5, probability of exclusion ranged from 0.311 8 to 0.826 3 （triplet） and from 0.197 9 to 0.712 1 （biplet）, and no significant deviations from Hardy-Weinberg equilibrium were observed. Based on the results of multidimensional scaling, principal component analysis and phylogenetic trees of the genetic distances between Sichuan Han population and the other 12 populations, Sichuan Han population was closest to Hubei Han population and was farthest to Xinjiang Uygur population. Conclusion The 19 autosomal STR loci showed a high polymorphism and discriminating ability in Sichuan Han population, which can provide a data foundation for personal identification, paternity test and population genetics study.

Construction of SNP-STR Multiplex Amplification System with Genetic Markers and Its Forensic Application / 法医学杂志

Objective To select and develop a SNP-STR multiplex amplification system with genetic markers compatible with current STR databases. To understand its genetic polymorphisms in Sichuan Han population and its application value in DNA mixture analysis. Methods Based on the STR genetic markers in commercial kits, SNPs adjacent to these STR markers were selected to be SNP-STR genetic markers. A SNP-STR multiplex amplification system with genetic markers based on allele-specific amplification was constructed using allele-specific amplification primers. The genetic polymorphism of the system in the Sichuan Han population was investigated and the efficiency of systems with different numbers of loci to detect the two individual DNA mixture samples was evaluated. Results An allele-specific multiplex amplification system constituted of 13 SNP-STR genetic markers was selected and constructed. In Sichuan Han population, the heterozygosity of each locus ranged from 0.76 to 0.88, and the combined discrimination power reached 0.999 999 999 999 999 968. In the analysis of the two individual DNA mixture samples： for single-locus amplification, the genotype of the minor components can still be detected when the mixture ratio reaches 1 000∶1; for multiple loci multiplex amplification, the maximum mixture ratio can reach 500∶1. As the number of loci in the system increased, the detection efficiency of the minor components in the DNA mixture decreased. Conclusion SNP-STR genetic markers have a higher polymorphism than STR. The multiplex amplification system made of SNP-STR genetic markers has a better analysis efficiency for mixed samples than traditional STR multiplex amplification system.

Ｒeview on the association of CAG short tandem repeats of androgen receptor gene with tumorigenesis and prognosis / 中华疾病控制杂志

@#Abnormal expression of androgen receptor ( AＲ) and AＲ-mediated signaling pathways are closely related to the occurrence，outcome，and prognosis of various human disease，and to some ex- tent，AＲ lead to gender differences in these diseases． However，the specific mechanism is still unclear． CAG short tandem repeat ( STＲ) sequence in exon 1 of AＲ gene negatively correlates with the transcriptional regulation activity，affects the synthesis and biological function of the target proteins，and plays an important role in the development and prognosis of various tumors，such as prostate cancer，breast cancer，bladder cancer，liver cancer，and endometrial cancer． In this review，we summarized the current studies on the association between AＲ gene CAG STＲ and the common tumors，in order to provide clues for further exploring the mechanism of AＲ-related tumors with high incidence and gender differences，and screening populations with high risk for the corresponding tumors．

Calculation of Likelihood Ratio for Identifying Half Sibling Relationship When Both Biological Mothers Participate / 法医学杂志

Objective To derive the formulae for likelihood ratio （LR） calculation of half sibling relationships when both mothers participate. Methods Based on the fact that both biological mothers participate in the identification of half sibling relationship between the two individuals, test hypothesis for the identification of half sibling relationship was established. Conditional probability ratios of genetic evidence under null hypothesis and alternative hypothesis conditions were simplified, and then applied to a real case of half sibling relationship identification. At the same time, the LR of half sibling relationships under the assumption that only a single biological mother or none of the biological mothers participate were respectively calculated. Results In the cases of identification of half sibling relationship from same fathers, with no biological father involved, after the same genetic indicator test analysis, when both biological mothers participate in the identification, the accumulated LR value was higher than that of accumulated LR with only a single biological mother or no parents participating. Conclusion When the autosome STR test is used for the identification and analysis of half sibling relationship between two individuals, the calculation of LR is more simple, intuitive and operable with both mothers participating. The biological mothers should participate in the test as much as possible, otherwise the number of STR loci would need to be increased for a more specific conclusion.

Genetic Structure Analysis of Y-Chromosome STR and SNP in Population of Wujiang Area, Suzhou City / 法医学杂志

Objective To analyze the genetic phenotypes of Y-chromosome STR and SNP in Han male population of Wujiang area, Suzhou City and explore the genetic structure of population of Wujiang area for further examination of regional-specific Y-SNP genetic markers ancestor haplogroups. Methods Blood samples of 472 Wujiang area Han males were randomly collected and genotyped by YfilerTM Plus PCR Amplification Kit. The allele frequencies and haplotype frequencies of each locus were obtained using the direct calculation method. Y-SNP haplogroups of each sample were estimated using Y-Predictor software and verified through experiments by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR）. Results A total of 453 haplotypes were found in the 27 Y-STR genetic markers in 472 Han males of Wujiang area. The haplotype diversity （HD） was 0.997 696 93, among which, the highest gene diversity （GD） value was DYF387S1a/b （GD=0.953 1） and the lowest was DYS438 （GD=0.321 8）. Based on genotyping data of 27 Y-STRs and 472 samples, 132 haplogroups from C, D, N, O and Q, etc downstream Y-SNP haplogroups were estimated and then verified through experiments. Conclusion This study is based on Y-chromosome STR haplotypes, and predicts Y-SNP haplogroups by Y-Predictor software, then uses ARMS-PCR to verify. Y-SNP genetic markers were introduced to achieve precise analysis of the genetic structure of male families in population of three towns in Wujiang area.

Analysis of Detection of Mixed Semen Stains with Different Immunological Test Methods and Case Applications / 法医学杂志

Objective To perform the separation and confirmation of mixed semen stains with immunological test method, and find a more effective method for the detection of mixed semen stains. Methods The semens of three volunteers were mixed. The mixed semen stains were processed and tested with prostate-specific antigen （PSA） colloidal gold immunoassay strip method, immunomagnetic beads method and laser capture microdissection, respectively. Statistics of the results of STR were gathered and compared with those of a single semen stain. Results After PSA colloidal gold immunoassay strip method testing, the samples showed a purplish red line in the test area and the control area. The results obtained with the immunomagnetic beads method showed a more complete and effective short tandem repeat （STR） sequence. The mixed semen stains were processed with laser capture microdissection and low volume amplified. The results were summarized and superimposed to obtain a complete single typing, which matched the single semen stain typing, with a typing success rate of 84.00%. Single suspect Y-STR typing was obtained with the application of the method above in actual cases, which provided evidence basis for rapid solving of the case. Conclusion The combination of PSA colloidal gold immunoassay strip method, immunomagnetic beads method and laser capture microdissection can be used to separate and confirm the mixed semen stains.

Application of Multiple Genetic Markers in Determination of Full and Half Sibling Relationship： A Case Report / 法医学杂志

Objective To investigate the application of the comprehensive use of multiple genetic markers in full and half sibling relationship testing through the identification of a case of suspected sibling relationship. Methods Genomic DNA were extracted from bloodstain samples from 4 subjects （ZHANG-1, ZHANG-2, male; ZHANG-3, ZHANG-4, female）. Autosomal STR loci, X-STR, Y-STR loci and polymorphisms of mtDNA HV-Ⅰ and Ⅱwere genotyped by EX20 STR kit, X19 kit, Data Y24 STR kit, and Sanger sequencing, respectively. Results According to autosomal STR based IBS scoring results, full sibling relationships were indicated among ZHANG-2, ZHANG-3 and ZHANG-4, but those were not indicated between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4. According to autosomal STR based FSI and HSI, with ITO method and discriminant function method, full sibling relationships among ZHANG-2, ZHANG-3 and ZHANG-4 were indicated, and half sibling relationships between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4 were also indicated. X-STR and mtDNA sequencing results showed that all the 4 samples came from a same maternal line, and Y-STR results showed that ZHANG-1 and ZHANG-2 did not come from a same paternal line, which supported the half sibling relationship between ZHANG-1 and ZHANG-2 or ZHANG-3 or ZHANG-4, verified by parental genotype reconstruction based on autosomal STR genotyping. Conclusion For the identification of sibling relationships, it is effective to have reliable results with the mutual verification and support of multiple genetic markers （autosomal STR, sex chromosomal STR and mtDNA sequence） and calculations （IBS, ITO, discriminant function method and family reconstruction）.

Network Analysis of Y-STR in Six Ethnic Populations in Guangxi and Its Forensic Significances / 法医学杂志

Objective To explore the distribution of genetic structure of Y-SNP and Y-STR genetic markers in different ethnic groups and its application in forensic science. Methods SNaPshot minisequencing was used to detect the polymorphisms of 12 Y-SNP loci in 439 males from 6 ethnic groups, including Guangxi Han, Guangxi Jing, Guangxi Miao, Guangxi Yao, Guangxi Zhuang and Guangxi Dong. DNATyperTM Y26 kit was used to multiplex-amplify 26 Y-STR loci. The PCR products were analyzed by 3130xl genetic analyzer. The network analysis of Y-STR haplotype under the same Y-SNP haplogroup was analyzed by Network 5.0 software. Results Six haplogroups defined by 12 Y-SNP loci were detected in 6 ethnic groups, and 362 haplotypes were detected in 26 Y-STR loci. The haplotype diversity was 0.996 6. In the C haplogroup, the samples from Guangxi Yao, Guangxi Zhuang and Guangxi Dong were clustered on different branches; in the O1 haplogroup, those from Guangxi Zhuang, Guangxi Miao and Guangxi Jing were relatively independent and clustered separately; in the O2 haplogroup, some samples from Guangxi Miao and Guangxi Yao were gathered in a cluster. Conclusion Based on the Y-STR network analysis of samples with identical haplogroup of Y-SNP, some ethnic groups can be preliminarily distinguished, which could be used to infer male suspects' ethnic group through detecting their genetic markers left in the crime scene.

Evaluating the Efficiency of REPLI-g® Single Cell Kit for Trace DNA Amplification / 法医学杂志

Objective To evaluate the efficiency of REPLI-g® Single Cell Kit for sample DNA amplification, and explore its application value in forensic trace DNA amplification. Methods Three DNA extraction kits were selected to extract DNA from peripheral blood of 10 unrelated individuals. The DNA yield and purity of the three DNA extraction kits were compared. According to the results of comparison, one DNA sample was selected to concentrate and dilute, then used as the initial sample of whole genome amplification （WGA）. REPLI-g® Single Cell Kit was used to amplify the initial sample at the whole genome level. The amplification yield and amplification times were calculated, and the distribution of DNA fragments was detected by agarose gel electrophoresis. Goldeneye® DNA ID System 20A Kit was used to perform the STR typing of the initial sample and DNA samples amplified at the whole genome level to evaluate the performance of REPLI-g® Single Cell Kit in trace DNA amplication in terms of purity and yield as well as the success rate of STR typing. Results After comparison, one DNA sample was selected from QIAsymphony® DNA Investigator® Kit extracts to concentrate and dilute as the initial sample of WGA. After amplifying the whole genome of a series of initial samples by REPLI-g® Single Cell Kit, the lowest average of amplification yield reached 8.77×103 ng, while the average of the corresponding amplification times reached 1.40×106. DNA fragments were large and concentrated. The STR typing success rate of WGA samples became lower with the decrease of initial samples used, but when the amount of samples was lower than 0.5 ng, the STR typing success rate of samples after DNA WGA was higher than that of samples without DNA WGA. Conclusion REPLI-g® Single Cell Kit can increase the yield of template DNA. Especially for trace DNA, the STR typing success rate can be improved to a certain extent.