Construction and evaluation of in-house methylation-sensitive SNaPshot system and three classification prediction models for identifying the tissue origin of body fluid / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The identification of tissue origin of body fluid can provide clues and evidence for criminal case investigations. To establish an efficient method for identifying body fluid in forensic cases, eight novel body fluid-specific DNA methylation markers were selected in this study, and a multiplex singlebase extension reaction (SNaPshot) system for these markers was constructed for the identification of five common body fluids (venous blood, saliva, menstrual blood, vaginal fluid, and semen). The results indicated that the in-house system showed good species specificity, sensitivity, and ability to identify mixed biological samples. At the same time, an artificial body fluid prediction model and two machine learning prediction models based on the support vector machine (SVM) and random forest (RF) algorithms were constructed using previous research data, and these models were validated using the detection data obtained in this study (n=95). The accuracy of the prediction model based on experience was 95.79%; the prediction accuracy of the SVM prediction model was 100.00% for four kinds of body fluids except saliva (96.84%); and the prediction accuracy of the RF prediction model was 100.00% for all five kinds of body fluids. In conclusion, the in-house SNaPshot system and RF prediction model could achieve accurate tissue origin identification of body fluids.

Genetic diversity analysis of forty-three insertion/deletion loci for forensic individual identification in Han Chinese from Beijing based on a novel panel / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Due to the virtues of no stutter peaks, low rates of mutation, and short amplicon sizes, insertion/deletion (InDel) polymorphism is an indispensable tool for analyzing degraded DNA samples from crime scenes for human identifications (Wang et al., 2021). Herein, a self-developed panel of 43 InDel loci constructed previously by our group was utilized to evaluate the genetic diversities and explore the genetic background of the Han Chinese from Beijing (HCB) including 301 random healthy individuals. The lengths of amplicons at 43 InDel loci in this panel ranged from 87 to 199 bp, which indicated that the panel could be used as an effective tool to utilize highly degraded DNA samples for human identity testing. The loci in this panel were validated and performed well for forensic degraded DNA samples (Jin et al., 2021). The combined discrimination power (PD) and combined probability of exclusion (PE) values in this panel indicated that the 43 InDel loci could be used as the candidate markers in personal identification and parentage testing of HCB. In addition, population genetic relationships between the HCB and 26 reference populations from five continents based on 19 overlapped InDel loci were displayed by constructing a phylogenetic tree, principal component analysis (PCA), and population genetic structure analysis. The results illustrated that the HCB had closer genetic relationships with the Han populations from Chinese different regions.

Analysis of genetic polymorphisms and mutations of 20 frequently used STR loci among ethnic Hans from Henan / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the genetic polymorphisms and mutations of 20 frequently used autosomal microsatellites among ethnic Hans from Henan.</p><p><b>METHODS</b>Peripheral blood samples of 2604 individuals were collected. DNA was amplified and genotyped using a PowerPlex(TM) 21 system. The frequencies, forensic parameters and mutation rates of the 20 short tandem repeat (STR) loci were analyzed.</p><p><b>RESULTS</b>A total of 323 alleles were found in this population and the allelic frequencies have ranged from 0.0003 to 0.5144. Except for D3S1358, TH01 and TPOX, mutations have been found in all of the remaining 17 STR loci, which totaled 47, with mutation rates ranging from 0 to 3.46 × 10.</p><p><b>CONCLUSION</b>The 20 STR loci selected by the PowerPlex(TM) 21 system are highly polymorphic among ethnic Hans from Henan, and may be of great value in forensic and human population studies. As no similar study has been carried out previously, above results may be of great value for individual discrimination and paternal testing.</p>

GENETIC POLYMORPHISM OF SIX Y CHROMOSOMAL STR IN CHINESE HUI ETHNIC GROUP / 药物分析学报

Objective To study genetic polymorphism of 6 Y chromosomal STR in Hui ethnic group living in Ningxia Hui ethnic autonomous region, in order to evaluate their usefulness in forensic science and enrich the Chinese genetic information resources. Methods We investigated 101 unrelated, healthy, male individuals of Hui ethnic group and studied their allelic frequency distribution and haplotype diversity of 6 Y chromosomal STR. Primer for each loci was labeled with the fluorescent by FAM (blue) or TAMRA(yellow). The data of Hui ethnic group were generated co-amplification, GeneScan, genotype, and genetic distribution analysis. Results 31 alleles and 43 phenotype(DYS385) were detected, with the frequencies ranging from 0.0099-0.7129. Out of a total of 101 individuals, 96 showed different haplotypes; 91 were unique; 5 were found 2 times. The haplotype diversity for 6 Y-STR loci was 0.9990. Conclusion The date obtained can be valuable for individual identification, paternity testing in forensic fields and for population genetics because of 6 Y-STR loci high polymorphism.

Reflection on the Ethical Issues Related to Paternity Testing / 中国医学伦理学

There is no defined legislation on paternity testing in present China,thus the testing status quo is in a mess to some extent.Together with other unfavorable factors including the unstable marital status in modern society,increasing extramarital sexual behaviors and illegitimate children,and the ever-heated testing competition among testing institutes driven by the economic interests and so forth,the paternity testing is on a sharp rise these years,which leads to a increasing chaos in paternity testing field.Social ethical crisis is partially responsible for the current problem,thus related ethical issues to paternity testing are discussed in this article.