Application Value and Research Progress of Human Microbiome in Sexual Assault Cases / 法医学杂志

In recent years, sexual assault cases have been on the rise, seriously infringing the legitimate rights and interests of women and children, causing widespread concern in society. DNA evidence has become the key evidence to prove the facts in sexual assault cases, but lack of DNA evidence or only DNA evidence in some sexual assault cases leads to unclear facts and insufficient evidence. With the emergence of high-throughput sequencing technology and the development of bioinformatics and artificial intelligence, new progress has been made in the study of human microbiome. Researchers have begun to use human microbiome for difficult sexual assault cases indentification. This paper reviews the characteristics of human microbiome, and its application value in the inferences of the body fluid stain origin, the sexual assault method, the crime time, etc. In addition, the challenges faced by the application of the human microbiome in practical case handling, the solutions and future development potential are analyzed and prospected.

SNP Panel Analysis of Ancestry Inference in East Asian Populations / 法医学杂志

Objective To develop an SNP Panel for East Asian population, which has a high individual identification rate and the capability of ancestry analysis. Methods The 55 SNP Panel by Professor KIDD of Yale University and the 128 SNP Panel by Professor SELDIN of Davis School of California University, 170 SNP Panel in total was used as the basis and its test data in the East Asian population was collected. The genetic parameters of SNP loci were calculated and combined with the results of heatmap analysis to screen SNP loci suitable for East Asian population. Some Tibetan and Han samples were tested. The possibility of using the SNP loci in ancestry inference was analyzed by means of STRUCTURE analysis, principal component analysis and heatmap analysis. Results A Panel with 45 SNPs （45 SNP Panel） was screened out, and the average genetic parameters of each SNP were better than 170 SNP Panel, with the same ancestry analysis and inference ability. Conclusion In terms of ancestry inference information, the 45 SNP Panel can completely replace the 170 SNP Panel and achieve the same ancestry analysis and inference ability. In genetic parameters, 45 SNP Panel is better than 170 SNP Panel in the East Asian population, which shows its important potential forensic application value.

Further characterization of six miniSTR loci in the Han population from China / 解放军医学杂志

Objective To describe the characteristics of two miniplex sets: NC01 (D10S1248, D14S1434 and D22S1045), which was recommended by EDNAP/ENFSI, and a new miniplex one (D2S2944, D18S872 and D19S591). Methods DNA was extracted using the Chelex-100 extraction method. The products were genotyped by ABI PRISM® 310 Genetic Analyzer and the results were analyzed with GeneScan 3.7 and GenoTyper 3.7 software. Results All loci meet Hardy-Weinberg equilibrium. The combined power of discrimination for the six loci in Chinese population was 0.9999 and the cumulative probability of exclusion was 0.9793. We also compared the sequencing data of NC01 with other different ethic groups. Conclusion Two miniplex sets were constructed. These miniSTR makers have different characteristics in different ethic groups.

Allele frequencies and species specificity of six short tandem repeat loci in Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop a set of new markers for forensic application, the authors have chosen 6 short tandem repeat(STR) loci to study the allele frequencies and species specificity in Chinese Han population in Chengdu.</p><p><b>METHODS</b>One hundred and ten EDTA-blood samples were collected from the unrelated individuals in Chengdu city, Sichuan province. DNA was extracted by Chelex-100 and amplified by the polymerase chain reaction(PCR). Polyacrylamide gel electrophoresis (PAGE) and silver staining were used to analyze the PCR products.</p><p><b>RESULTS</b>The polymorphisms of all 6 STR loci have been obtained in Chinese Han population in Chengdu, the alleles of D4S2366, D4S2367, D6S474, D6S1281, D2S1396 and D20S601 being 7, 7, 6, 7, 5, 7, the observed heterozygosity of them being 0.802, 0.708, 0.770, 0.627, 0.542, 0.672, the discrimination power of them being 0.887, 0.828, 0.849, 0.848, 0.794, 0.865; and the power of exclusion of them being 0.602, 0.441, 0.544, 0.325, 0.227, 0.386. Evaluated by comparison with the data from 14 different animals as controls, the 6 STR loci contain good specificity of human beings.</p><p><b>CONCLUSION</b>The 6 STR loci are highly polymorphic and can play a key role in species identification. They are new candidate markers for forensic personal identification and paternity testing.</p>

Proceedings of human mitochondrial DNA study and its applications to forensic medicine / 法医学杂志

The mitochondrial DNA (mtDNA) is a small circular genome located within the mitochondria in the cytoplasm of the cell. Evidence of its existence first arose over 30 years ago. Now the field of the mitochondria is one of the fastest growing disciplines in biomedicine which is driven by fundamentally interesting questions. These questions are mainly about the way of mitochondria evolving and energy producing. In addition, what the consequences of mitochondrial genome mutations in diseases are? How program cell death is regulated? What happens to mitochondria when aging? These questions remain to be answered and the basic understanding of them will contribute to anthropological and forensic analysis, as well as therapy of many diseases. The following review has brought this question to notice by summarizing recent mitochondria research.

Proceeding of research on X chromosome genetic markers / 法医学杂志

The development of Human Genome Project (HGP) makes it possible and more important to reveal the variations or polymorphisms precisely between different individuals and populations. Due to the characters of their high polymorphism and value in disease-linkage analysis as well as pharmacogenomnics, genetic markers on X chromosome have attracted much more attention of current medical and forensic scientists. This report summarized the proceeding of research on X chromosome genetic markers in the clinical and forensic context.