Objective To study the genetic polymorphism of 20 autosomal short tandem repeats(STR)loci in Yunnan Han population. Methods The 20 STR loci(D3S1358,D1S1656,D6S1043,D13S317,Penta E,D16S539,D18S51,D2S1338,CSF1PO,Penta D,TH01,vWA,D21S11,D7S820,D5S818,TPOX, D8S1179,D12S391,D19S433 and FGA)which were included in the PowerPlexR21 System kit were genotyped in 1085 unrelated Han individuals living in Yunnan province using multiplex amplication. PCR products were separated and analyzed by the AB 3130 automatic genetic analyzer and GeneMapper ID v3.2 software. Forensic parameters of each locus were calculated by Modified-Powerstates software. Results All the studied loci except for TH01 and TPOX were highly polymorphic. The observed heterozygosity(Ho)ranged from 0.6130 to 0.8743. Match probability(PM)ranged from 0.0179 to 0.2030. Power of discrimination(DP)ranged from 0.7970 to 0.9821. Probability of exclusion(PE)ranged from 0.3067 to 0.7432. Paternity index(PI)ranged from 1.2919 to 3.9766. Polymorphism information content(PIC)ranged from 0.5598 to 0.8958. No deviation of the Hardy-Weinberg equilibrium was observed. Conclusion The studied 20 STR loci were highly polymorphic in Yunnan Han population and could be used in forensic individual identification and paternity testing practice.

Epigenetics is the study of heritable changes in gene expression other than the changes in the underlying DNA sequence. Such changes include DNA methylation,genomic imprinting,X chromosome inactivation and non-coding RNA regulation. Recent progresses on epigenetics offer new ideas to tackling these problems in forensic science,including determination of the necessary allele in paternity,identification of fetal paternity testing in embryonic period,discrimination of identical twins,origination analysis of tissue,and individual age estimation. This review focuses on the main concept of epigenetics and its application in the field of forensic science.

Objective To study the correlation between the polymorphisms of NR3C1 gene and aggressive behavior in Yunnan Han population.Methods Five SNPs of the NR3C1 gene (rs6190,rs6191,rs6198,rs41423247 and rs56149945) were genotyped in 194 unrelated prisoners who committed violent-crimes and 301 healthy controls using improved Multiplex-ligase-detection reaction(iMLDR) method,and the data were statistically analyzed with the SPSS19.0soflware and PHASE2.1platform.Results Single locus analysis showed that the allelic distribution of rs6191and rs41423247did not show significant differencesbetween the control groupand the aggressive-behavior group as well as the robbery sub-group and intentional injury sub-group.However,significant difference was foundin the rs41423247 genotype distribution betweencontrol groupand robbery sub-group (p=0.048).In addition,there were no significant differences for the four haplotypes between the control group,the attack group,the robbery subgroup and the intentional injury subgroup.Conclusion These findings indicate that rs41423247 polymorphism of the NR3C1gene might play a role in susceptibility to aggressive behavior and rs6191 polymorphismmay not be correlated withaggressive behavior.