DNA Molecular Identification of Human Phenotypic Characteristics--New Progress Over the Past Five Years / 法医学杂志

Molecular identification of human externally visible characteristic （EVC）, which is also called forensic DNA phenotyping （FDP）, can serve as a "molecular witness" when the routine investigations can not determine the identity of a criminal and the DNA database find no match after comparison. FDP could assist in investigation of cases by inferring the externally visible phenotypic characteristics from DNA obtained from the biological materials left at crime scenes, or unknown corpses. In the last few years, studies on the selection of EVC related molecular markers have been reported frequently and some of the EVCs could already be inferred with a certain accuracy, such as hair color and iris color. Further fundamental research on molecular genetics of human external phenotypic characteristics, as well as the continuous innovation on molecular biological technology would promote the rapid development of DNA molecular identification of human phenotypic characteristics.

Genetic Polymorphisms of 30 InDel Loci in Ewenki Ethnic Group from Inner Mongolia / 法医学杂志

OBJECTIVES@#To study the genetic polymorphisms of 30 insertion/deletion （InDel） loci and evaluate their forensic application in Ewenki ethnic group from Inner Mongolia.@*METHODS@#Peripheral blood samples were collected from 87 unrelated healthy individuals in Ewenki ethnic group. Genomic DNA were extracted, and 30 InDel loci of the samples were multiplex amplified and genotyped. Hardy-Weinberg balance tests were preformed for all loci and genetic parameters were calculated by modified PowerStats v1.2 software. The linkage disequilibrium between loci were tested by SNPAnalyzer v2.0 software. Based on the allele frequencies of 30 InDel loci, the genetic relationships between Ewenki ethnic group and other populations were evaluated by analysis of molecular variance, principal component analysis and phylogenetic reconstruction.@*RESULTS@#After correction, 30 InDel loci conformed to Hardy-Weinberg equilibrium. It was found that the pairwise InDel loci were in linkage equilibrium after Bonferroni correction. The results of population genetics indicated that Ewenki ethnic group had close genetic relationships with Henan Han and Beijing Han populations; whereas it was significantly different from several populations in Europe and Mexico.@*CONCLUSIONS@#There are relatively high genetic polymorphisms on 30 InDel loci of Ewenki ethnic group from Inner Mongolia, which can be used as a helpful supplement application for STR detection system.

The impact of gender, age and tissues in vitro on estimating postmortem interval by FTIR spectroscopy / 法医学杂志

To investigate the influence of such individual factors as gender, age and tissues in vitro to the postmortem interval (PMI) by the Fourier transform infrared (FTIR) spectrometer in animal experiments. SD rats were classified into male and female groups, different age groups (21-day, 42-day and 63-day group), and tissues in vitro and in vivo groups. The rats were sacrificed by cervical dislocation, whose bodies were kept in a controlled environmental chamber set at (20+/-2) degrees C and 50% humidity. The liver, kidney, spleen, myocardium, brain, lung and skeletal muscle tissues were collected for measurement from time zero to 48 h postmortem. With the change of PMI, no obvious changes were found in the main FTIR absorbance peaks and their ratios at different time points. All the experimental groups showed no significant changes when compared with the controls. The gender, age and tissues in vitro were not found to be contributing factors in the estimation of PMI via FTIR spectroscopy.