Application and Prospect of RNA Profiling Analysis in Forensic Body Fluid Identification / 法医学杂志

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. This review summarizes the research progress of RNA markers in body fluids identification, including the RNA markers that have been effectively verified in current research and their advantages and disadvantages. Meanwhile, this review prospects the application of RNA markers in forensic medicine.

Application Prospect of Massively Parallel Sequencing in Mixed Stain Detection / 法医学杂志

Mixed stains is the common biological sample in sexual crime cases. Its analysis and DNA profiles interpretation are one of the difficulties in forensic examination. The current genetic marking of mixed stain detection mainly rely on capillary electrophoresis （CE） separation technology, and the analysis methods of the results are mainly inclusion rate and likelihood methods. Because CE has limited resolution and is not able to exploit the efficacy of each genetic marker, its ability to split mixed stain is limited. In recent years, the emerging massively parallel sequencing （MPS） technique not only can obtain the base sequence information of genetic markers, but also is capable of detecting multiple genetic markers simultaneously, and thus derives new analytical methods, bringing new opportunities for forensic detection and analysis of mixed stain. This paper intends to review the application prospects of conventional mixed stain analyses and MPS technique, therefore to provide references for later research and practice.

Progress on Molecular Biology for Forensic Ancestry Inference / 法医学杂志

Forensic ancestry inference refers to the application of ancestry inference of population genetics in forensic practice, which aims to assist police investigation and judicial trial. With the rapid development and extensive use of genomics, DNA as a direct carrier of genetic information, has soon replaced various phenotypic markers and become the main research topics of forensic ancestry inference. This paper reviews different kinds of genetic markers used for forensic ancestry inference, the statistical analysis methods applied, and the prospects of the development in this field.

Application of SNP-STR Composed by D18S51 and Three SNPs of Its Flanking Region in Paternity Testing / 法医学杂志

Objective To develop a SNP-STR haplotype by consisting of the SNP and STR genetic markers, both of which locate in a haplotype block. To investigate its distribution in Han population from Chengdu, and explore its application in some special cases of paternity testing. Methods D18S51, one of the high mutation rate STR markers in combined DNA index system (CODIS), and three SNP loci rs8089331, rs8094489 and rs7236090 in its flanking region, were chosen to establish SNP-STR. Its haplotype was obtained by nested allele-specific polymerase chain reaction, and the relevant distribution of 75 unrelated individuals were investigated in Han population from Chengdu. The SNP-STR haplotype was tentatively applied in duo paternity testing cases with D18S51 incompatibility. Results The SNP-STR typing method was established and a total of 43 haplotypes were obtained successfully in Han popula-tion from Chengdu. Its polymorphism was 0.9486, and duo paternity testing cases were resolved by this method. Conclusion SNP-STR shows high diversity and can be applied in the identifications of some special paternity testing cases.

Detection technologies of microRNA and their prospects for forensic applications / 法医学杂志

MicroRNA (miRNA) belongs to a class of small, non-coding RNA molecules that contains 18-25 nucleotides and regulates gene expression at post-transcriptional level. Many miRNAs are highly conserved and display timing- and tissue-specific expression. With the advance of the miRNA detection technologies, miRNA has been introduced to forensic science as a potentially novel set of genetic markers of forensic body fluid identification, species identification and PMI estimation. In this article, the detection methodologies of miRNA are reviewed, and their potential applications in forensic practice and research future are also discussed.

Degenerate oligonucleotide primed-PCR technology establishment and its sensitivity test analysis / 法医学杂志

OBJECTIVE@#To establish a whole genome amplification testing system based on degenerate oligonucleotide primed-PCR (DOP-PCR) and to explore its reliability and sensitivity.@*METHODS@#DOP-PCR amplified production was detected by fluorescent labeled multiplex STR amplification and capillary electrophoresis detection system to determine reliability and sensitivity of DOP-PCR system.@*RESULTS@#DOP-PCR system was successfully established and the detection sensitivity reached 5 cells (30 pg) by pretreatment of DOP-PCR and then detection of STR genotyping.@*CONCLUSION@#The system established in this study is reliable and more testing sensitive for forensic trace evidence.

Low template DNA profiling and its application in forensic science / 法医学杂志

Low template DNA (LTDNA) has been widely applied in the field of forensic science in recent years. However, the application of low copy number(LCN) analysis is still controversial in certain forensic. This paper focus on the definition of LCN and LTDNA, casework because of its inherent limiting factors. the validity and application of LCN in forensic science, methods of typing, quality control, replicate analysis, detection thresholds and then reviews the latest development of LCN in forensic science.

The mechanism of inhibitory effect on parotid gland secretion with local injection of botulinum toxin type A in the rat / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To determine the mechanism of inhibitory effect of botulinum toxin type A (BTX-A) on parotid gland secretion.</p><p><b>METHODS</b>Female Wistar rats (n = 18) were randomly divided into saline injection group (n = 6) and BTX-A injection group ( n = 12), respectively. 0.1 ml of saline was injected into left parotid gland and 2.5 U of BTX-A injected into right parotid gland. Rats were sacrificed at day 7, 12 and 35 post-injections respectively for morphology and vasoactive intestinal polypeptide (VIP) immunoreactivity of parotid gland.</p><p><b>RESULTS</b>Following BTX-A injection, some atrophic cells and reduction of number of VIP-immunoreactive (VIP-IR) fibers were found in gland and tube at day 7 (P < 0.05); at day 12, there was more obvious reduction of VIP-IR fibers around tube and vessels and atrophy of cells in BTX-A injection gland than saline injection gland (P < 0.001); at day 35, the glandular cells and VIP-IR fibers were similar to saline injection group.</p><p><b>CONCLUSIONS</b>BTX-A is effective for temporary elimination of hyperfunctioning sialorrhea via inhibition of VIP release which plays a key role in modulation of parotid glands secretion.</p>

DNA-based personal identification in disaster / 法医学杂志

The disaster is a sudden unexpected event that causes serious human injuries and deaths as well as missing persons. The main tasks of forensic DNA laboratories are to identify victim in the disaster. After reviewed the previous disasters and related studies, we proposed a new procedure of DNA identification for the use of disaster in the future, which includes preparation works, samples collection, samples storage, DNA extraction, typing, data analysis and interpretation of results. Some experiences and problems about the DNA identification are also discussed.

Analysis and application of haplotype in forensic medicine / 法医学杂志

Haplotype is a lineable combination of alleles at multiple loci that are transmitted together on chromosome or mitochondrion. In October 2002, the international HapMap project started and aimed at mapping the haplotype blocks of human being and discovering the Tag SNPs by determining the DNA sequence variation patterns, variation frequency and their relationship. This review summarizes the formation and distribution of the haplotype and the current three haplotype-analysis methods including the methodology of experiment, the deduction from pedigrees and the statistic method. When an allele linkage disequilibrium occurs, the genetic probability would be evaluated by haplotype. The importance of haplotype has been recognized and its application has been gradually increased in forensic sciences. The current focus on haplotype study in forensic science involves Chromosome Y, Mitochondrial DNA and Chromosome X, which are useful supplements of genetic marks.

The polymorphism of ten STR loci in Chinese Han population in Chengdu / 法医学杂志

OBJECTIVE@#To obtain data of polymorphism distribution of 10 short tandem repeat (STR) D1S2145, D3S2433, D5S1507, D5S2502, D8S2319, D9S926, D16S767, D17S2181, GATA140E03, GATA196B10 in Chinese Han population in Chengdu and to evaluate their usefulness in the field of forensic science and their species specificity.@*METHODS@#DNA of 100 unrelated individuals of Chengdu Han population was extracted with Chelex method, amplified by PCR, then typed with silver staining after polyacrylamide gel electrophoresis(PAGE). Ten different animals were selected as the controls in this study for evaluating the species specificity of the ten STR loci.@*RESULTS@#In the ten STR loci of Chengdu Han population, 6, 5, 8, 5, 6, 7, 7, 5, 7 and 7 alleles were found, respectively. 17, 14, 28, 15, 16, 18, 15, 14, 19 and 21 genotypes were observed in the ten loci, respectively. The allele and genotype frequency distributions of the ten loci were detected no deviation from the Hardy-Weinberg law of equilibrium. By comparison with the data from 10 different animals, the species specificity of D3S2433, D5S1507, D5S2502, D8S2319 and GATA196B10 was good, but part of animals had amplification product at typing field of the other loci.@*CONCLUSION@#The 10 STR loci mentioned above are highly polymorphic and can be used in the forensic personal identification and paternity testing.

Analysis of Y-chromosomal biallelic polymorphisms in Sichuan Han of Chinese population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To evaluate the forensic utility of Y-single nucleotide polymorphisms (SNPs) markers.</p><p><b>METHODS</b>Allele-specific PCR, restriction enzyme digestion or direct PCR were performed to examine 10 different SNP loci on Y chromosome, namely M9, M15, M45, M89, M95, M122, M134, M145, M173 and P25 in 161 Chinese Han males.</p><p><b>RESULTS</b>A total of 8 of the 10 SNPs are reported to be polymorphic in Chinese. The gene diversity for the loci showing polymorphism ranged from 0.988/0.012-0.752/0.248, with a power of discrimination 0.094-0.373. Loci M122 and M134 were the most polymorphic markers in Chinese Hans. Nine different haplogroups with frequencies from 1.2% to 51.6% were observed and 3 of the haplogroups-K*(x O2a, O3, P), O3*(x O3e) and O3e were found in 75.2% of Chinese Hans.</p><p><b>CONCLUSION</b>A comprehensive gene diversity data of Y chromosome and haplogroups were obtained in Sichuan Han population, which will be served as the base for using these Y-SNP markers in forensic medicine and individual identification in Sichuan Hans.</p>

Evaluation of Genetic Markers in a Novel Diagnostic Strategy for Trisomy Based on Short Tandem Repeats / 现代生物医学进展

Background:In the newly published article,we presented a novel STR-based diagnostic strategy for trisomy.When applying the strategy to the detection of the copy number of the selected chromosome,it is necessary at first to construct a multi-marker diagnostic system for trisomy by selecting the optimal chromosome-specific STR markers from numerous STR polymorphisms in human genome.Objective:Attempting to provide a reliable method for selecting optimal STR markers to construct a diagnositic system of high efficiency,in this study,we further described the quantitative evaluation of single STR marker and multimarker system during the marker selection.Methods:We deduced the formulae of three-allele detection rae(TDR)and the probability that three different alleles are observed in a diagnostic system.(P),by which we can quantitatively evaluate efficacy of a STR marker and cumulative efficacy of a multi-marker diagnostic system.Furthermore,we applied them to a multi-marker diagnostic system for trisomy 21 which was constructed in the previous study.Results:The TDR values of nine STR markers in our diagnostic system for trisomy 21 ranged from 0.203 to 0.638.The probability that three different alleles are observed in the system is above 0.95.Conclusion:The numerical values obtained from the formulae can provide a basis for the selection of optimal STR markers and the determination of the number of STR markers needed in a system with high efficacy.

Evaluation of Genetic Markers in a Novel Diagnostic Strategy for Trisomy Based on Short Tandem Repeats / 现代生物医学进展

Background:In the newly published article,we presented a novel STR-based diagnostic strategy for trisomy.When applying the strategy to the detection of the copy number of the selected chromosome,it is necessary at first to construct a multi-marker diagnostic system for trisomy by selecting the optimal chromosome-specific STR markers from numerous STR polymorphisms in human genome.Objective:Attempting to provide a reliable method for selecting optimal STR markers to construct a diagnositic system of high efficiency,in this study,we further described the quantitative evaluation of single STR marker and multimarker system during the marker selection.Methods:We deduced the formulae of three-allele detection rae(TDR)and the probability that three different alleles are observed in a diagnostic system.(P),by which we can quantitatively evaluate efficacy of a STR marker and cumulative efficacy of a multi-marker diagnostic system.Furthermore,we applied them to a multi-marker diagnostic system for trisomy 21 which was constructed in the previous study.Results:The TDR values of nine STR markers in our diagnostic system for trisomy 21 ranged from 0.203 to 0.638.The probability that three different alleles are observed in the system is above 0.95.Conclusion:The numerical values obtained from the formulae can provide a basis for the selection of optimal STR markers and the determination of the number of STR markers needed in a system with high efficacy.

Calculation of paternity index for paternity testing with considering mutation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To formulate recommendations in calculation of paternity index in paternity testing under considering mutations.</p><p><b>METHODS</b>Different formulas under considering mutations were developed according to Brenner method.</p><p><b>RESULTS</b>Different formulas under considering mutations were obtained. Both true exclusion and false exclusion of paternity were easily distinguished using these formulas when the genetic pattern was inconsistent with paternity.</p><p><b>CONCLUSION</b>The scientific evidence for paternity testing can be obtained using these formulas under considering mutations when both the combined probability of exclusion and the paternity index meet the threshold values. However, when either the combined probability of exclusion or the paternity index can not meet the threshold values, more genetic markers should be added.</p>

The application of palynology in forensic medicine / 法医学杂志

Palynology, one science of plant's pollen and spores, has been proven to be a new frontier discipline. Because of the characteristics of pollen and spores, such as small size, light weight, large amount, and difficult to be found, they can leave physical evidence and provide new clues to solve a case. Therefore palynology has a good prospect for practical application in forensic medicine. The paper intends to analyze the advantage and limitation of palynology in forensic medicine by reviewing its general characteristics, classification, morphology, and disseminating circadian rhythm. We hope to provide some reference to apply palynology in forensic medicine.

A study of paternity testing with considering mutation / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To formulate recommendations in the evaluation of results of genetic analyses in paternity testing under considering mutations.</p><p><b>METHODS</b>A total of 15 short tandem repeat(STR) loci were employed for this study, which were included CSF1PO, FGA, TH01, TPOX, VWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, PentaD and PentaE. Both 100 cases of true trio and 100 cases of false trio were investigated.</p><p><b>RESULTS</b>The numbers of mismatch alleles in different STR loci were observed in 100 cases of false trio. The different distributions of paternity index were obtained, including the changes of paternity index in each case of true trio under simulated mutations.</p><p><b>CONCLUSION</b>In order to avoid the effect of mutations, the exclusion of paternity was never considered on the basis of a single locus. The threshold values of the combined probability of exclusion and the paternity index were important for both exclusion and inclusion of paternity. The scientific evidence for paternity testing can be obtained when both the combined probability of exclusion and the paternity index meet the threshold values. However, when either the combined probability of exclusion or the paternity index can not meet the threshold values, more genetic markers should be added.</p>

Multiplexed mutagenically separated PCR assay for rapid detection of SNP loci in mitochondrial DNA coding region / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To develop a multiplexed mutagenically separated PCR (MS-PCR) for single nucleotide polymorphism (SNP) loci typing in mitochondrial DNA coding regions and to study the applications in investigating the allele frequencies and haplotypes of four SNP loci in mitochondrial DNA coding regions in Chinese Chengdu Han population.</p><p><b>METHODS</b>Four SNP loci C12705T, A8701G, G8584A and C10400T, two allele specific forward primer with 4 bases different in size and a common reverse primer were designed for SNP typing. The primers simultaneously were amplified in a single tube. The genotyping of SNPs was determined by the two allele specific fragments different in size after polyacrylamide gel and silver staining.</p><p><b>RESULTS</b>The different SNP loci comprised a single band with different size respectively. Typing results were completely consistent with those by direct sequencing. The allelic frequencies of C12705T, A8701G, G8584A and C10400T were 0.3813/0.6187, 0.4813/0.5187, 0.8250/0.1750 and 0.4938/0.5062 respectively. A total of 6 different haplotypes was identified and the genetic diversity reached 0.7137.</p><p><b>CONCLUSION</b>Multiplexed MS-PCR is a simple, rapid, accurate and efficient method for SNP typing, which will be very powerful for SNPs in the database establishing of mitochondrial DNA coding regions, the testing of forensic and population genetics research.</p>

Forensic application of 9 Y-STRs fluorescence-labeled multiplex amplification system / 法医学杂志

OBJECTIVE@#In order to increase significantly the discriminatory potential of Y-STR systems available to the forensic community, we have developed a system capable of simultaneously amplifying 9 Y-STR loci by fluorescence-labeled multiplex PCR technique.@*METHODS@#Primers of STR loci DYS434, GATA-A10, DYS438 and DYS439 were labeled with 6-FAM, primers of STR loci DYS531, DYS557, DYS448 were labeled with HEX, and primers of STR loci DYS456, DYS444 were labeled with TAMRA, respectively. PCR products were analyzed using capillary electrophoresis and GeneScan Software on the ABI Prism310 DNA Analyzer. Series experiments were carried out to evaluate the useful value in forensic application such as the sensitivity, male specificity and genotyping DNA different tissues of the same individual.@*RESULTS@#9 Y-STR loci were exactly determined following optimization of the polymerase chain reaction. In a sample of 120 males, a total of 105 different haplotypes was identified, 97 of them being unique. Overall, haplotype diversity was 0.996 8. It was proved that genotyping of these 9 Y-STR loci in some sexual crime should be prior to that of automosomal STR.@*CONCLUSION@#The results suggest that the newly constructed 9-plex will be very powerful for establishing Y-STR database, population genetic studies and mixture stains identification.

Constructing of STR slippage model by optimizing some factors / 法医学杂志

OBJECTIVE@#To construct STR slippage model and study factors involved in this procedure.@*METHODS@#DNA samples were amplified with the technology of Degenerate oligonucleotide- primed PCR, then their products were taken as later DNA template and their STR genotype were analyzed by optimizing several factors.@*RESULTS@#STR slippage model was constructed.@*CONCLUSION@#Several factors were involved in the produce of STR slippage, such as amount of modulate DNA, concentration of MgCl2, property of DNA polymerase, motif sequence of STR loci, sample, etc.