[Establishment of 43-plex SNP Typing System and Its Forensic Application].

OBJECTIVES: To evaluate the application of 43-plex SNP typing system in forensic science. METHODS: The typing of 43 SNP loci in 123 unrelated Han individuals from East China was detected by MALDI-TOF-MS. The application value of 43-plex SNP typing system was assessed according to the forensic parameters of population genetics. RESULTS: All the 43 SNP loci of 123 individuals showed no significant departure from Hardy-Weinberg equilibrium （P>0.05）. Excepted rs1355366, rs2270529, rs10776839 and rs938283, there were 39 SNP loci had minor allele frequencies （MAF）, which were greater than 0.25. Among the 25 loci MAFs, 24 ranged from 0.4 to 0.5, while 3 were close to 0.4. The DP, CDP, PIC, Ho, PEtrio and PEduo of the 43 SNP loci were 0.290 1-0.654 4, 1-9.8×10⁻¹¹, 0.170 8-0.500 0, 0.155 7-0.593 5, 0.085 4-0.250 0 and 0.014 6-0.125 0, respectively. The CPEtrio and CPEduo were 0.999 986 and 0.992 436 1, respectively. CONCLUSIONS: The 43-plex SNP typing system in present study shows a high polymorphism, which can be an effective supplement and verification for traditional STR genetic markers. It also can be used with other commercial kits for the forensic paternity testing and individual identification.

[Assessment on Application of 24 Y-STR Loci in Forensic Science].

OBJECTIVES: To select a Y-STR marker system with strong haplotype identification ability, appropriate mutation rate and high compatibility and to assess its forensic application. METHODS: The 24 Y-STR loci were tested by self-built fluorescent multiplex system, and the forensic assessment was conducted by 139 pairs of father-son samples collected in Jinan, Shandong province. RESULTS: Totally 176 alleles were identified among the 24 Y-STR loci in the sample of 139 unrelated individuals labeled with father, and the gene diversity （GD） distributed between 0.083 7 （DYS645）-0.966 9 （DYS385a/b）. According to the 24 Y-STR loci, 139 different haplotypes were detected from 139 unrelated male individuals labeled with father in Han population of Shandong province and with no shared haplotype observed. The overall haplotype diversity （HD） was 1 and the discrimination capacity （DC） was 1. A total of 5 one-step mutations events were observed among the 24 Y-STR loci in 139 pairs of father-son. The average mutation rate was 0.001 5 [95% CI （0.000 5, 0.003 5）]. CONCLUSIONS: The system of 24 Y-STR loci shows a strong individual recognition ability and low mutation rate in the population in Jinan, Shandong province, and it has good application value in forensic science.

[Review of Second Generation Sequencing and Its Application in Forensic Genetics].

The rapid development of second generation sequencing （SGS） within the past few years has led to the increasement of data throughput and read length while at the same time brought down substantially the sequencing cost. This made new breakthrough in the area of biology and ushered the forensic genetics into a new era. Based on the history of sequencing application in forensic genetics, this paper reviews the importance of sequencing technologies for genetic marker detection. The application status and potential of SGS in forensic genetics are discussed based on the already explored SGS platforms of Roche, Illumina and Life Technologies. With these platforms, DNA markers （SNP, STR）, RNA markers （mRNA, microRNA） and whole mtDNA can be sequenced. However, development and validation of application kits, maturation of analysis software, connection to the existing databases and the possible ethical issues occurred with big data will be the key factors that determine whether this technology can substitute or supplement PCR-CE, the mature technology, and be widely used for cases detection.