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Nonbinary single-nucleotide polymorphisms (SNPs) are potential forensic genetic markers because their discrimination power is greater than that of normal binary SNPs, and that they can detect highly degraded samples. We previously developed a nonbinary SNP multiplex typing assay. In this study, we selected additional 20 nonbinary SNPs from the NCBI SNP database and verified them through pyrosequencing. These 20 nonbinary SNPs were analyzed using the fluorescent-labeled SNaPshot multiplex SNP typing method. The allele frequencies and genetic parameters of these 20 nonbinary SNPs were determined among 314 unrelated individuals from Han populations from China. The total power of discrimination was 0.9999999999994, and the cumulative probability of exclusion was 0.9986. Moreover, the result of the combination of this 20 nonbinary SNP assay with the 20 nonbinary SNP assay we previously developed demonstrated that the cumulative probability of exclusion of the 40 nonbinary SNPs was 0.999991 and that no significant linkage disequilibrium was observed in all 40 nonbinary SNPs. Thus, we concluded that this new system consisting of new 20 nonbinary SNPs could provide highly informative polymorphic data which would be further used in forensic application and would serve as a potentially valuable supplement to forensic DNA analysis.

The Han population accounts for the majority of the Chinese population. Hunan is a large province located at 108°47′–114°15′ E and 30°08′–24°38′ N in Southern China, specifically in the area in the...

To study the population data of Y-chromosome STRs (Y-STRs) of Han population resided in Hunan province, we analyzed haplotypes of 26 Y-STRs (DYS19, DYS385a/b, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS481, DYS533, DYS549, DYS570, DYS576, DYS635, DYS643, DYS388, DYS449, DYS460, and YGATAH4) in 310 unrelated male individuals using a commercially available Goldeneye® DNA ID 26Y system. The calculated average gene diversity values ranged from 0.4211 to 0.9590 for DYS438 and DYS385a/b loci, respectively. The discriminatory capacity was 96.77 % with 300 observed haplotypes. Population relationships between Hunan Han and eight other populations available from Y-chromosome haplotype reference database (YHRD) were compared. The results showed that the Han population resided in the Hunan district is significantly different from other populations. Our results also indicated that these 26 Y-STR loci were highly genetically polymorphic in the Hunan Han population and of great value in forensic application.

The species identification of forensically important sarcophagid flies (Diptera: Sarcophagidae) is very difficult and requires strong taxonomic expertise. More and more methods according to the mitochondrial DNA (MtDNA) and nuclear fragments are raised, but the current methods of molecular identification have some defects, such as insufficient discrimination power, high cost, time-consuming and so on. In this study, the CO II sequences of sarcophagid flies were analyzed to establish the SNP-based genotyping system for the first time. Using this system by PSQ, we can identify the species of forensically important Sarcophgid flies with high discrimination power at a low cost in the short time. The SNPs marker system shows a new idea for genetic identification of forensic insects.

Body provides a home for diverse commensal microbiota. Microorganisms such as fungi have major roles in this microbial community stability. Postputrefaction fungi have been recorded in association with decomposed mammalian cadavers in disparate regions. The succession and diversity of these fungi are reviewed with a view to their potential as a forensic tool. The researches of mycology would be an interface to forensic investigation and may provide a means to estimate PMI within serious decomposition. To evaluate the use of succession and diversity of fungi species for PMI estimation, we investigate the Internal Transcribed Spacer (ITS) of fungi community on 3 points of time of rat carcasses conducted by Illumina MiSeq platform. Through high-throughput sequencing, several fungi genus such as Aspergillus , Ophiocordyceps are found in community succession. The community structure of each sample significantly differs in taxon richness and relative abundance patterns within decomposition progress. The succession and diversity of fungi community in corpse decomposition revealed by the indicator of ITS would be a potential forensic tool for PMI estimation.

The estimation of postmortem interval (PMI) is one of the most difficult tasks in forensic practice, especially in putrefied bodies. After death, organisms are decomposed by a variety of enzymes and microorganisms. To investigate the succession of bacterial community in the decomposition process, rat remains were placed outside to decompose under natural conditions in Changsha city, China. Bacterial communities from two regions (buccal cavity and rectum) were sampled when experiment animals were alive, soon after they died and at various time span after death. Bacterial samples were analyzed by high throughput metagenomic sequencing of 16S rRNA gene conducted on an Illumina MiSeq platform. Our data showed that several bacteria genera were potentially useful for estimating the PMI, such as Streptococcus , Ignatzschineria , Acinetobacter , Aggregatibacter , Prevotella and Proteus . There were significant bacterial community structure differences in taxon richness and relative abundance patterns through the decomposition process and across different body sites. As decomposition progressed, a negative linear relationship for taxon richness was found along with a shift from aerobic bacteria to anaerobic bacteria. We first reported the bacterial biodiversity in the decomposition process in Chinese terrestrial scenarios and climatic conditions. Bacteria have a remarkable potential for estimate the PMI and next generation sequencing is a novel method to support the application of bacteria in forensic science.

The mitochondrial genome of Helicophagella melanura, a representative of the Sarcophagidae family, was completely sequenced for the first time. The genome is a double-stranded circular molecule of 15,190 bp length, including the 37 genes and 1 non-coding AT-rich region. The gene contents of the mtDNA were identical to those observed in the ancestral arthropod. The total base composition of Helicophagella melanura mitochondrial genome is 39.42% for A, 36.22% for T, 14.71% for C and 9.65% for G and in the order A > T > C > G. The mitochondrial genome data of Helicophagella melanura is useful markers for species discrimination in forensic entomology and for phylogenetic analysis.

Sarcophaga africa (S. africa) is a significant medical and forensic insect which belongs to the Sarcophagidae. The species identification of the forensically important genus Sarcophaga is difficult and requires strong morphology and taxonomic expertise. With the sequencing technique improved, we report the complete mitochondrial genome of the S. africa for the first time to assist species identification. The 37 genes presented in the 15,144 bp circular genome has been found which include 13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The array of the genes has much resemblance with other discovered insects. The overall base compositions of A, G, C and T are 39.43%, 9.64%, 14.61% and 36.31% respectively. The complete mitochondrial genome of S. africa could be valuable to enriching the Dipteran mitochondrial genomes and be helpful for entomologists to screen reliable molecular markers in the species identifications with forensic entomology purposes or phylogenetic analysis.