Identification Methods of Tumor Tissue Origin Based on Different STR Typing Kits.

Objectives: To establish the identification method of tumor tissue origin based on commonly used STR typing kits.

Methods: ForenSeq DNA Signature Prep kit was used to detect the typing of 27 autosomal STR loci in 55 paired tumor tissue samples (tumor tissue paired with normal tissue of the same individual) and 75 unrelated individual whole blood samples. The genotyping data of full sibling pairs and parent-child pairs of 55 tumor tissues were simulated.

Establishment and Validation of a Multiplex PCR Detection System for the Identification of Six Common Edible Meat Components.

Objectives: To establish a rapid, accurate, and sensitive multiplex PCR detection method for the simultaneous identification of the six common edible meats (beef, lamp, chicken, pork, goose, duck), and to evaluate its application value in meat adulteration identification.

Methods: Based on complete mitochondrial genomic sequences of six species in the GenBank database, DNA sequences (cattle：; sheep：; chickens：; pig：; goose：; duck：) with intra-species conservation and inter-species specificity were screened, and species-specific primers were designed to construct a multiplex PCR detection system that can simultaneously detect the meat of six common species. The species specificity, sensitivity and reproducibility of the system were studied, and the simulated mixture sample detection was performed.

Establishment and Application of a 42-plex Microhaplotype Assay in Forensic Genetics.

Objectives: To establish and forensically verify a 42 microhaplotypes (mircohaps, MHs) multiplex assay system based on next-generation sequencing (NGS), and to explore the application value of this system in the practice of forensic genetics.

Methods: A total of 42 highly polymorphic MHs were selected from previous studies, and sequenced by the MiSeq FGx platform to verify the repeata-bility, sensitivity, specificity, stability, and mixture analysis ability of the detection system. Through population genetic investigation of 102 unrelated Chinese Han individuals in Liyang City, Jiangsu Province, China, the application value of this system in forensic genetics was evaluated.

Traceability of Geographic Origin Using Human Skin and Oral Microbiota.

Objectives: To explore the possibility of using human skin and oral microorganisms to estimate the geographic origin of an individual through the sequencing analysis of bacterial 16S rRNA gene.

Methods: Microbial DNA was extracted from the palm and oral microorganisms of the Han population in Shanghai and Chifeng, Inner Mongolia, and the composition and diversity of the microbiota were analyzed by full-length 16S rRNA gene sequencing. Then, differential species were screened and a geographic location prediction model was constructed.

Application of SNaPshot Technology in Semen-Specific cSNP Genetic Marker.

Objectives: To explore the feasibility of genetic marker detection of semen-specific coding region single nucleotide polymorphism (cSNP) based on SNaPshot technology in semen stains and mixed body fluid identification.

Methods: Genomic DNA (gDNA) and total RNA were extracted from 16 semen stains and 11 mixtures composed of semen and venous blood, and the total RNA was reverse transcribed into complementary DNA (cDNA). The cSNP genetic markers were screened on the validated semen-specific mRNA coding genes.

Cross-Platform Application of DNA Methylation Age Estimation Model in Eastern Chinese Han Population.

Objectives: To evaluate the forensic application value of an age estimation model based on DNA methylation in eastern Chinese Han population, and to provide a theoretical basis for exploring age estimation models suitable for different detection platforms.

Methods: According to the 6 age-related methylation sites in the published blood DNA methylation age estimation models of Chinese Han population, the DNA methylation level of 48 samples was detected by pyrosequencing and next-generation sequencing (NGS). After submitting DNA methylation levels to the age estimation model, the DNA methylation ages were predicted and compared with their real ages.

Mitogenome evidence shows two radiation events and dispersals of matrilineal ancestry from northern coastal China to the Americas and Japan.

Although it is widely recognized that the ancestors of Native Americans (NAs) primarily came from Siberia, the link between mitochondrial DNA (mtDNA) lineage D4h3a (typical of NAs) and D4h3b (found so far only in East China and Thailand) raises the possibility that the ancestral sources for early NAs were more variegated than hypothesized. Here, we analyze 216 contemporary (including 106 newly sequenced) D4h mitogenomes and 39 previously reported ancient D4h data. The results reveal two radiation events of D4h in northern coastal China, one during the Last Glacial Maximum and the other within the last deglaciation, which facilitated the dispersals of D4h sub-branches to different areas including the Americas and the Japanese archipelago.

Age Estimation Based on DNA Methylation and Its Application Prospects in Forensic Medicine.

With the improvement of DNA methylation detection techniques, studies on age-related methylation sites have found more age-specific ones across tissues, which improves the sensitivity and accuracy of age estimation. In addition, the establishment of various statistical models also provides a new direction for the age estimation of tissues from different sources. This review summarizes the related studies of age estimation based on DNA methylation from the aspects of detection technology, age-related cytosine phosphate guanine site and model selection in recent years.

Application and Prospect of RNA Profiling Analysis in Forensic Body Fluid Identification.

In forensic physical evidence identification, the accurate identification of the individual origin and their body fluid composition of the biological samples obtained from the crime scene play a critical role in determining the nature of a crime. In recent years, RNA profiling has become one of the fastest developing methods for body fluids identification. Due to the characteristics of tissue or body fluid specific expression, various types of RNA markers have been proven to be promising candidate markers for body fluids identification in previous studies.

Efficiency Analysis of Uncle-Nephew Relationship Identification by Increasing STR Markers and Adding Reference Samples.

Objectives: To estimate the system efficiency of uncle-nephew relationship identification by increasing STR markers and adding reference samples based on the test results of simulated data and real samples, so as to provide references for selecting the appropriate number of STRs and reference samples for uncle-nephew relationship identification.

Methods: Five common models of uncle-nephew relationship identification were constructed by adding different reference samples. In each model, the likelihood ratio (LR) for 10 000 pairs of uncle-nephew relationships and 10 000 pairs of unrelated individuals were simulated by detecting 19, 39 or 55 STRs, and the system efficiency at different thresholds was simulated.

Establishment of Multiplex Amplification System of STR Loci in and Its Forensic Application.

Objectives: To construct a STR loci multiplex amplification system and to evaluate its application value by testing the technical performance.

Methods: The published STR loci data were reviewed and analyzed to select the STR loci and sex identification loci that could be used for individual identification and genetic identification. The fluorescent labeling primers were designed to construct the multiplex amplification system.

Effects of Peripheral Blood Different Pretreatment Methods and Preservation Time on RNA Quality.

Objectives: To evaluate the effects of different pretreatment methods and preservation time on RNA quality of peripheral blood samples, and to optimize the preservation method of peripheral blood samples.

Methods: Eight pretreatment methods were used to preprocess the peripheral blood from 3 healthy unrelated individuals and the treated samples were stored at -80 ℃. Total RNA of samples was extracted using Quick-RNA Miniprep Plus kit.

Forensic Application of ForenSeq DNA Signature Prep Kit in Zhengjiang She Ethnic Group.

Objectives: To evaluate the ability of the ForenSeq 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 ForenSeq 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.

Effect of organic solvent on enzymatic degradation of cyclic PBS-based polymers by lipase N435.

Poly(butylene succinate-co-cyclohexane dimethanol succinate) (P(BS-co-CHDMS)) and poly(butylene succinate-co-butanediol cyclohexanedicarboxylic acid) (P(BS-co-BCHDA)) were catalytically degraded by Candida antarctica lipase Novozyme 435 (N435) in CHCl and THF. The results indicated that the degradation rate was P(BS-co-CHDMS) > P(BS-co-BCHDA) > poly(butylene succinate) (PBS). The degradation rate of copolyesters was higher in CHCl than in THF, the highest degradation rate of 67% being obtained for P(BS-co-CHDMS).

[Research Progress of circRNA and Its Significance in Forensic Science].

RNA has received more attention in the field of forensic medicine and the development of the new biological markers based on RNA shows great significance in the analysis of complex cases. circular RNA (circRNA) is a kind of non-coding RNA which is widely reported recently. Although the regulatory mechanisms of generation and expression are not fully clear, the existing research indicates that circRNA has important biological functions.

Downregulation of RPL15 may predict poor survival and associate with tumor progression in pancreatic ductal adenocarcinoma.

Early diagnosis and treatment in pancreatic ductal adenocarcinoma (PDAC) is still a challenge worldwide. The poor survival of PDAC patients mainly due to early metastasis when first diagnosed and lack of prognostic biomarker. Ribosomal protein L15 (RPL15), an RNA-binding protein, is a component of ribosomal 60S subunit.

Progress of DNA-based Methods for Species Identification.

Species identification of biological samples is widely used in such fields as forensic science and food industry. A variety of accurate and reliable methods have been developed in recent years. The current review shows common target genes and screening criteria suitable for species identification, and described various DNA-based molecular biology methods about species identification.

[Development of an 18 X-InDel multiplex PCR system].

Objective: To investigate Insertion/Deletion (InDel) polymorphism on the X chromosome and to screen 18 InDel loci for the Chinese Han population as a forensic DNA typing system auxiliary.

Methods: Eighteen X-InDel markers were selected using the Human Genome Browser and dbSNP database. Multiplex PCR primer pairs of selected X-InDel markers were designed using Primer 3 software and divided into 3 groups according to the amplified fragment length, labeled by FAM, HEX and TAMRA fluorescence dye, respectively.