Multiple genetic analyses for Chinese Hunan Han population via 46 A-STRs.

BACKGROUND: Short tandem repeats (STRs) are important as common genetic markers in forensic identification and population genetics due to their highly polymorphic nature. AIMS: To explore genetic polymorphisms of the Chinese Hunan Han population and further dissect genetic relationships among the Hunan Han and other populations from China. SUBJECTS AND METHODS: In this study, samples of 394 unrelated healthy individuals from the Chinese Hunan Han population were analysed using 46 autosomal-STRs (A-STRs). Thirteen previously reported populations (6378 individuals) from China were subsequently collected for population genetic analyses based on 23 shared A-STRs. RESULTS: In the Hunan Han population, a total of 452 alleles were detected in 46 A-STRs with allelic frequencies spanning from 0.0013 to 0.5571. Except for the Penta D locus in linkage disequilibrium, the combined power of discrimination and the combined power of exclusion for 45 A-STRs in the Hunan Han population were 0.999999999999999999999999999999999999999999999999510314 and 0.999999999999999726596, respectively. Results of interpopulation differentiation, principal component analysis, and phylogenetic relationship analyses uniformly showed that the Hunan Han have closer genetic affinities with Han populations from different Chinese regions and a geographically close ethnic minority group, namely the Hubei Tujia. CONCLUSION: To summarise, these 46 A-STRs showed high polymorphism in the Chinese Hunan Han population for forensic practice.

Forensic characteristic and population structure dissection of Shaanxi Han population in the light of diallelic deletion/insertion polymorphism data.

The genetic polymorphisms of diallelic deletion/insertion polymorphic (DIP) loci in the Shaanxi Han population are still not clearly characterized. Herein, allele frequencies and forensic application efficiencies for 30 diallelic DIP loci were investigated in 506 unrelated healthy Han individuals from Chinese Shaanxi province. Based on population data of the same 30 diallelic DIP loci, the genetic differentiations, hierarchical clustering relationships and population architectures among Shaanxi Han and other 50 populations were further dissected through genetic and bioinformatics analyses. Results indicated that most of the 30 diallelic DIP loci were relatively high polymorphisms in the Shaanxi Han population; and there were the genetically intimate relationships between Shaanxi Han and the East Asian populations. In summary, this study provided significant insights into genetic background of Shaanxi Han population, and the multiplex amplification of these 30 diallelic DIP loci was appropriate for forensic individual identification and population genetic research in Shaanxi Han population.

Developing and population analysis of a new multiplex panel of 18 microhaplotypes and compound markers using next generation sequencing and its application in the Shaanxi Han population.

Compound marker consists of two different types of genetic markers, like deletion/insertion polymorphism and single nucleotide polymorphism in the genomic region of 200 bp, and microhaplotype consists of a series of closely linked single nucleotide polymorphisms in a small DNA segment (<300 bp), which show great potential for human identifications and mixture analyses. In this study, we initially selected 23 novel genetic markers comprising 10 microhaplotypes and 13 compound markers according to previously reported single nucleotide polymorphism or deletion/insertion polymorphism loci. Genetic distributions of these 23 loci in different continental populations showed that they could be used as valuable loci for forensic human identification purpose. Besides, high informativeness values (>0.1) were observed in six loci which could be further employed for forensic ancestry analyses. Finally, 18 loci were successfully developed into a multiplex panel and detected by the next generation sequencing (NGS) technology. Further analyses of these 18 loci in the studied Shaanxi Han population showed that 15 loci exhibited relatively high expected heterozygosities (>0.5). Cumulative power of discrimination (0.999 999 999 99 4835) of these 18 loci revealed that the multiplex panel could also be utilized for human identifications in the studied Shaanxi Han population.

Temporal dynamics changes in the vaginal fluid microbiome: Implications for body fluid identification and estimating time since deposition (TsD) for forensics.

Vaginal fluid analysis plays a crucial role in sexual assault investigations. However, vaginal fluid found at crime scenes is usually subject to a certain duration of exposure. This study thus aimed to assess the influence of different durations of exposure to indoor environment on the vaginal microbiota. The 16S rDNA high-throughput sequencing was used on vaginal fluid samples exposed for short-term (30 days) and long-term (240 days), respectively. Despite potential contamination from environmental microorganisms, particularly following long-term exposure, the results indicated that the vaginal microbiota after exposure was still dominated by Lactobacillus. Both in short-term and long-term exposure involving vaginal fluid, there were clusters with time-dependent characteristics, wherein the relative abundances of associated microbial genera showed a trend of increasing or decreasing over time. In addition, each bodily fluid presented with a unique array of dominant bacterial genera, enabling the differentiation of exposed vaginal fluid samples from other bodily fluids (semen, skin, saliva, feces) with a remarkable 98.75 % accuracy rate. Furthermore, the mean absolute error achieved by the long-term deposition time prediction model was 13.54 days. The mean absolute error for the short-term deposition time prediction model was notably lower, reaching just 2.05 days. In summary, this study investigates the variations in microbial communities within vaginal fluid subjected to different indoor exposure durations and explores their potential in body fluid identification and estimating the time since deposition, thereby contributing valuable supporting evidence in forensic investigations.

Genetic polymorphisms and population genetic analyses of 57 autosomal InDel loci in Hubei Tujia group.

Introduction: The Tujia is the eighth most populous population in China, but its genetic structure has not been fully studied. Methods: In this study, we utilized 57 autosomal Insertion/deletion (InDel) loci to evaluate the genetic polymorphisms and efficiency of forensic applications in the Chinese Hubei Tujia group, and analyzed the genetic structure variances among the studied group and other 26 different reference populations from five continents in 1000 Genomes Project (1KG). Results: The results showed that 57 InDels have no significant deviations from Hardy-Weinberg equilibrium and linkage equilibrium. The combined power of discrimination (CPD) and the combined probability of exclusion (CPE) values for 57 InDels were 0.99999999999999999999999699822 and 0.999975177214539 in the Hubei Tujia group, respectively. In addition, the results of genetic structure analyses indicated that the Hubei Tujia group has close genetic relationships with the Chinese Han population and other East Asian populations. Discussion: These 57 autosomal InDels can be used as reliable tools for forensic individual identification and paternity testing, and are more suitable for East Asian populations. Furthermore, three InDels (rs72085595, rs145941537, and rs34529639) are promising for inferring ancestral information.

Genetic characterization evaluation of a novel multiple system containing 57 deletion/insertion polymorphic loci with short amplicons in Hunan Han population and its intercontinental populations analyses.

Deletion/insertion polymorphism (DIP) is a promising genetic marker of DNA length polymorphism. However, there are relatively few studies on the exploration of DIP genetic polymorphisms and investigation of population genetic data at present, which limits its application in forensic identification. In this study, the genetic polymorphisms of 57 autosomal DIPs and forensic application evaluations of the novel panel were analyzed in Chinese Hunan Han population using capillary electrophoresis platform, andthe differences of genetic polymorphic distributions at these loci were compared among the Hunan Han and 26 reference populations. The present results showed the combination of total 57 DIPs could be a robust tool for forensic individual identification and paternity testing. Due to the different allele frequency distributions in the different continental populations, the system could also effectively distinguish among East Asian, European and African populations.

An interpretation of the genetic polymorphism and population genetic background of Ankang Han population via a novel InDel panel.

In this research, genotyping data of 43 InDel loci in 311 Han individuals in Ankang City, Shaanxi Province, China were detected using a self-developed five-dye multiplex amplification panel. The allelic frequencies and forensic parameters of all InDel loci were calculated. The combined power of discrimination and probability of exclusion values were 0.999 999 999 999 999 998 827 39 and 0.999 887 424, respectively, which demonstrated that this 43-InDel panel was powerful for individual identifications in Ankang Han population. Moreover, genetic distances, pairwise FST values, principal component analyses, phylogenetic trees and STRUCTURE analyses were performed to investigate the genetic affinities between Ankang Han and reference groups. Population genetic investigations indicated that Ankang Han population had a close genetic relationship with Southern Han population compared with other reference groups.

Development and Validation of a Novel Five-Dye Short Tandem Repeat Panel for Forensic Identification of 11 Species.

Species identification of unknown biological samples is of fundamental importance for forensic applications, especially in crime detection, poaching, and illegal trade of endangered animals as well as meat fraud. In this study, a novel panel was developed to simultaneously identify 10 different animal species (Gallus domesticus, Anas platyrhynchos domesticus, Ovis aries, Sus scrofa domesticus, Bos taurus, Equus caballus, Columba livia domestica, Rattus norvegicus, Mus musculus, and Canis lupus familiaris) and human beings by amplifying 22 short tandem repeat (STR) loci in a multiplex PCR using a set of five fluorescently labeled dyes. This novel 22-STR panel was validated by optimization of PCR conditions as well as species specificity, sensitivity, reproducibility, precision, DNA mixture, and tissue/organ consistency. The results of developmental validation showed that the 22-STR loci achieved high species specificity among 10 animal species and human beings, and the sensitivity of this panel was 0.09 ng. This 22-STR panel identified different meats in mixed samples, and the minimum detected mixture ratio in the current test was 10% (0.1 ng/1 ng). This sensitive, accurate, and specific 22-STR panel can be used for forensic species identification and the detection of meat fraud and adulteration.

[Primary investigation of methamphetamine-induced toxicity in PC12 cells].

OBJECTIVE: To investigate the mechanism of methamphetamine (METH)-induced toxicity in PC12 cells. METHODS: PC12 cells were treated with METH for 24 h at the doses of 0, 0.5, 1.0, 1.5, 2.0, or 2.5 mmol/L. The morphological changes of the cells were observed under inverted microscope after the treatment. MTT assay and flow cytometry were used to assess the cell viability and apoptotic rates, respectively, and the level of nitric oxide (NO) was measured by enzyme reduction method. RESULTS: The PC12 cells exposed to METH were morphologically featured by cell shrinkage, dendrite disruption and disappearance of cell reticular formation. METH exposure caused a dose-dependent reduction in the cell viability (P<0.01), resulting in also increased cell apoptotic rate and significant elevation of NO in the cell culture supernatant (P<0.05). CONCLUSION: METH exposure induces cytotoxicity and injury of differentiated PC12 cells, leading to decreased cell viability and increased cell apoptosis and NO level. Cell apoptosis and excessive NO production are involved in METH-induced cytotoxicity.