New Advances, Challenges and Opportunities in Forensic Applications of Microbiomics / 法医学杂志

The succession of microbiota is closely associated with several essential factors, including race, sex, health condition, lifestyle, postmortem interval, etc., and it has great potential application value in forensic medicine. This paper summarizes recent studies on the forensic applications of the microbiome, including individual identification, geographical feature identification, origin identification of the tissue or body fluid, and postmortem interval estimation, and introduces the current machine learning algorithms for microbiology research based on next-generation sequencing data. In addition, the current problems facing forensic microbiomics such as the extraction and preservation of samples, construction of standardization and database, ethical review and practical applicability are discussed. Future multi-omics studies are expected to explore micro ecosystems from a comprehensive and dynamic perspective, to promote the development of forensic microbiomics application.

The Role of Forensic Medicine in Responding to Emergencies and New Major Epidemics / 法医学杂志

In recent years, human beings are constantly facing the threat of emerging infectious diseases. Forensic technology plays a unique role in responding to the emergencies and new epidemics. In epidemic prevention and control, forensic partitioners can provide important clues for the identification of vector animal species and the traceability of pathogen regions based on non-human DNA testing technology. In epidemic-related judicial practice, forensic partitioners bear more and more evidence responsibilities in dealing with biosafety laws-related issues, such as improper handling of epidemics and vaccine safety issues, which require forensic evidence. In terms of pathogen tracing, forensic physical evidence examinations identify species and individuals through biological materials extracted from the scene of death and autopsy of infectious diseases, are expected to provide informative clues for epidemiological investigations and point out the direction for pathogen tracing. In addition, forensic pathological examination can provide an important pathophysiological basis for determining the cause of death and the mechanism of death through autopsy, also offer necessary scientific evidence for clarifying the epidemiological characteristics of the epidemic and predicting the development trend of the epidemic.

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.

New Opportunities and Challenges for Forensic Medicine in the Era of Artificial Intelligence Technology / 法医学杂志

Traditional forensic identification relies on forensic experts to manually extract information and provide identification opinions based on medicine, biology and other fields of knowledge combined with personal work experience, which is not only time-consuming and require great effort, but also affected by subjective factors that are difficult to overcome. In the era of big data, the booming development of artificial intelligence brings new ideas to forensic medicine. In recent years, forensic researchers at home and abroad have conducted many studies based on artificial intelligence technology, such as face recognition, age and gender identification, DNA analysis, postmortem interval estimation, injury and cause of death identification, showing the feasibility and advantages of using artificial intelligence technology to solve forensic identification problems. As a new means of technology that has adapted to the development of the times, artificial intelligence has brought new vitality to forensic medicine, but at the same time also some new challenges. How to deal with these challenges scientifically and form a new mode of 'artificial intelligence plus forensic medicine' with artificial intelligence and forensic medicine developing collaboratively is a new direction for the development of forensic medicine in the era of big data.

Detection of Ancestry Information of Urumqi Mongolians Based on the AIM-InDels Loci Multiplex System / 法医学杂志

Objective To explore the genetic background and structure of Urumqi Mongolians, the previously developed 39-AIM-InDels panel for ancestry inference was utilized in the present study. Methods The blood samples of 145 unrelated healthy Urumqi Mongolian individuals were collected and genotyped. The compositions of ancestry information of Urumqi Mongolians were studied with 17 different populations from three continents （East Asia, Europe and Africa） as reference populations. Then, multiple population genetics and bioinformatics analysis methods were applied, the Fst and DA values between matched populations were compared and analyzed, PCA analysis was performed and a phylogenetic tree was constructed. The proportions of ancestry information components of Urumqi Mongolians were analyzed with Structure software, etc. Results The ancestry information components of Urumqi Mongolian group in different intercontinental populations accounted for 89%, 7%, and 3% of East Asian, European, and African populations, respectively. Compared with other intercontinental populations, Urumqi Mongolian group and East Asian populations have lower Fst and DA values, and they were in the same cluster in PCA analysis as well. In a phylogenetic tree, the Urumqi Mongolian group was in the same branch as East Asian populations. Conclusion Urumqi Mongolian group had relatively close genetic relationships with East Asian populations, and the proportion of its East Asian ancestry was about 89%.

DNA Molecular Identification of Human Phenotypic Characteristics--New Progress Over the Past Five Years / 法医学杂志

Molecular identification of human externally visible characteristic （EVC）, which is also called forensic DNA phenotyping （FDP）, can serve as a "molecular witness" when the routine investigations can not determine the identity of a criminal and the DNA database find no match after comparison. FDP could assist in investigation of cases by inferring the externally visible phenotypic characteristics from DNA obtained from the biological materials left at crime scenes, or unknown corpses. In the last few years, studies on the selection of EVC related molecular markers have been reported frequently and some of the EVCs could already be inferred with a certain accuracy, such as hair color and iris color. Further fundamental research on molecular genetics of human external phenotypic characteristics, as well as the continuous innovation on molecular biological technology would promote the rapid development of DNA molecular identification of human phenotypic characteristics.

Genetic Polymorphisms of 30 InDel Loci in Ewenki Ethnic Group from Inner Mongolia / 法医学杂志

OBJECTIVES@#To study the genetic polymorphisms of 30 insertion/deletion （InDel） loci and evaluate their forensic application in Ewenki ethnic group from Inner Mongolia.@*METHODS@#Peripheral blood samples were collected from 87 unrelated healthy individuals in Ewenki ethnic group. Genomic DNA were extracted, and 30 InDel loci of the samples were multiplex amplified and genotyped. Hardy-Weinberg balance tests were preformed for all loci and genetic parameters were calculated by modified PowerStats v1.2 software. The linkage disequilibrium between loci were tested by SNPAnalyzer v2.0 software. Based on the allele frequencies of 30 InDel loci, the genetic relationships between Ewenki ethnic group and other populations were evaluated by analysis of molecular variance, principal component analysis and phylogenetic reconstruction.@*RESULTS@#After correction, 30 InDel loci conformed to Hardy-Weinberg equilibrium. It was found that the pairwise InDel loci were in linkage equilibrium after Bonferroni correction. The results of population genetics indicated that Ewenki ethnic group had close genetic relationships with Henan Han and Beijing Han populations; whereas it was significantly different from several populations in Europe and Mexico.@*CONCLUSIONS@#There are relatively high genetic polymorphisms on 30 InDel loci of Ewenki ethnic group from Inner Mongolia, which can be used as a helpful supplement application for STR detection system.

A simple method for assessment of RNA integrity in laser capture microdissection samples / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a simple method for assessment of RNA integrity in laser capture microdissection (LCM) samples.</p><p><b>METHODS</b>The total RNA were isolated from the LCM samples and the sections before and after microdissection and examined by agarose gel electrophoresis. Real-time PCR was employed to assess the RNA from LCM samples, and the quantity of RNA was theoretically estimated according to the average total RNA product in mammalian cells (10 ng/1000 cells).</p><p><b>RESULTS</b>When the total RNA from the sections before and after microdissection was intact, the RNA from LCM samples also had good quality, and the 28S and 18S rRNAs were visualized by ethidium bromide staining. Real-time PCR also showed good RNA quality in the LCM samples.</p><p><b>CONCLUSION</b>A simple method for quantitative and qualitative assessment of the RNA from LCM samples is established, which can also be applied to assessment of DNA or proteins in LCM samples.</p>

Frequencies distribution of human leukocyte antigen-B27 subtypes in healthy Chinese / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the frequencies distribution of human leukocyte antigen (HLA)-B27 subtypes in unrelated healthy Chinese.</p><p><b>METHOD</b>Polymerase chain reaction sequence-based typing (PCRSBT) was used to determine HLA high-resolution genotypes of 825 unrelated healthy Chinese.</p><p><b>RESULTS</b>A total of 25 HLA-B27-positive individuals and 8 HLA-B27 subtypes were detected. These subtypes and their corresponding frequencies were B * 2704 (30.77%) , B * 2705 (23.08%), B * 2707 (19.23%), B * 2711 (7.69%), B * 2712 (7.69%), B * 2701 (3.85%), B * 2713 (3.85%) and B * 2721 (3.85%).</p><p><b>CONCLUSION</b>The data obtained through PCR-SBT method may serve as important reference for the research of relationship between HLA-B27 subtypes and some diseases such as ankylosing spondylitis.</p>

HLA-A, B, DRB1 gene polymorphism of Beijing population was studied by high-resolution polymerase chain reaction sequence-based typing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the gene polymorphism of human leukocyte antigen (HLA)-A, B, DRB1 loci in the population of Beijing region, and research on the application feasibility of polymerase chain reaction sequence-based typing (PCR-SBT) method.</p><p><b>METHODS</b>PCR-SBT method was applied to determine HLA- A, B, DRB1 genotypes of 618 unrelated healthy individuals of Beijing region.</p><p><b>RESULTS</b>A total of 84 different alleles and 199 genotypes of HLA-A, 143 alleles and 366 genotypes of HLA-B, 122 alleles and 286 genotypes of HLA-DRB1 were detected.</p><p><b>CONCLUSION</b>The results showed the characteristics of HLA-A, B, DRB1 distributions, and provided more comprehensive and accurate gene data that may serve as normal reference values for all of Beijing people.</p>

Genetic polymorphism of 9 STR loci in Han nation population in Shandong Province / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study genetic polymorphism of 9 STR loci in Han nation population in Shangdong Province.</p><p><b>METHODS</b>We investigated 100 unrelated individuals of Han nation population in Shandong Province and studied their genetic distribution of 9 STR loci and Amelogenin locus. Primers of 10 loci were labeled with the NHS-ester fluorescent dye 5-FAM (blue), Joe (green) or NED (yellow). The data of Han nation population were generated by multiple amplification and subjected to GeneScan, genotype and genetic distribution analysis.</p><p><b>RESULTS</b>83 alleles and 220 genotypes were observed, with the corresponding frequency of 0.0050-0.4050 and 0.0100-0.2100. The average of heterozygosity was 0.7778, the accumulated discrimination power was 0.9999. The accumulated probability of exclusion paternity was 0.9999. The polymorphism information content was 0.5823-0.8396.</p><p><b>CONCLUSIONS</b>Chi-Square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium.</p>