多种遗传标记分析在1例半同胞鉴定中的综合应用

目的通过对1例半同胞亲缘关系的检验,探讨多种遗传标记在同父异母半同胞关系鉴定中的应用。方法分别使用39个常色体STR遗传标记、23个Y染色体STR遗传标记、12个X染色体STR遗传标记对赵3、赵4、赵5与赵1、赵2是否为半同胞亲缘关系进行检验。结果依据常染色体、Y染色体及X染色体STR的分型结果,采用家系基因型重建的方法可以推断出赵4(可疑半同胞)与赵1、赵2之间系无关个体,支持赵3(可疑半同胞)、赵5(可疑半同胞)与赵1、赵2为同父异母半同胞关系。结论对于同父异母的半同胞鉴定,综合应用多种遗传标记,并采用家系基因型重建的方法进行分析可获得较为可靠的鉴定意见,仅使用ITO法计算半同胞指数或判别函数法分析则难以提供可靠的鉴定意见。     

DNA identification of "Earthquake McGoon" 50 years postmortem

This report describes the genetic identification of James "Earthquake McGoon" McGovern, a WWII fighter ace who perished in Laos while providing supplies to French troops during the French Indochina war. Because reference samples were unavailable for all of the potential casualties, testing of the entire mitochondrial genome, autosomal STRs and Y-chromosomal STRs was performed to increase the genetic information available for analysis. Kinship analyses performed on the evidentiary data and numerous indirect family references for McGovern excluded other possible casualties and definitively established McGovern's identity. This particular case demonstrates the practical utility of novel research technologies and aggressive genetic typing protocols in the identification of aged, degraded remains.     

Application of plant DNA markers in forensic botany: genetic comparison of Quercus evidence leaves to crime scene trees using microsatellites

As highly polymorphic DNA markers become increasingly available for a wide range of plant and animal species, there will be increasing opportunities for applications to forensic investigations. To date, however, relatively few studies have reported using DNA profiles of non-human species to place suspects at or near crime scenes. Here we describe an investigation of a double homicide of a female and her near-term fetus. Leaf material taken from a suspect's vehicle was identified to be that of sand live oak, Quercus geminata, the same tree species that occurred near a shallow grave where the victims were found. Quercus-specific DNA microsatellites were used to genotype both dried and fresh material from trees located near the burial site and from the material taken from the suspect's car. Samples from the local population of Q. geminata were also collected and genotyped in order to demonstrate that genetic variation at four microsatellite loci was sufficient to assign leaves to an individual tree with high statistical certainty. The cumulative average probability of identity for these four loci was 2.06x10(-6). DNA was successfully obtained from the dried leaf material although PCR amplification was more difficult than amplification of DNA from fresh leaves. The DNA profiles of the dried leaves from the suspect's car did not match those of the trees near the crime scene. Although this investigation did not provide evidence that could be used against the suspect, it does demonstrate the potential for plant microsatellite markers providing physical evidence that links plant materials to live plants at or near crime scenes.     

A comparison of endogenous and exogenous RNA reference marker as relevant for accurate Post-Mortem Interval estimation

The Post Mortem-Interval (PMI), also known as time since death, is of relevance for forensic routine casework and serves primarily as the basis for the determination of the time that has passed since the time of death. The existing, “classical” approaches are characterised by certain limitations because they are predominantly based on morphological examinations.The present study deals with the assessment of two molecular messengerRNA-markers in different kinds post-mortem human specimens concerning their ability to use them for the estimation of the time of death. Moreover, a comparison between carefully selected endogenous and one exogenous reference marker for the normalisation of the gene expression data as relevant for accurate PMI estimation is drawn.The evaluation showed that the used approach is methodologically useful but on consideration of the achieved results it was only possible to determine slightly meaningful tendencies. The tested exogenous reference marker was not suitable for sufficient data normalisation whereas the endogenous reference markers showed a stable expression. However, it was not possible to recognise a specific expression level of the genes within a PMI group when endogenous reference markers were used.     

Collection and direct amplification methods using the GlobalFiler™ kit for DNA recovered from common pipe bomb substrates

When analyzing DNA from exploded pipe bombs, quantities are often in trace amounts, making DNA typing extremely difficult. Amplifying minute amounts of DNA can cause stochastic effects resulting in partial or uninterpretable profiles. Therefore, the initial DNA collection from “touch” evidence must be optimized to maximize the amount of DNA available for analysis.This proof-of-concept study evaluated two different swab types with two direct amplification strategies to identify the most effective method for recovering DNA from common pipe bomb substrates. PVC and steel pipes, electrical tape, and copper wire spiked with epithelial cells were swabbed with cotton or microFLOQ® Direct Swabs and amplified directly or via a pre-treatment prior to STR amplification.Not only was the microFLOQ® Direct Swab protocol the quickest method with the least risk of contamination, but in combination with direct amplification, the microFLOQ® Direct Swabs also generated the most complete STR profiles.     

Internal Validation of RapidHIT®ID ACE Sample Cartridge and Assessment of the EXT Sample Cartridge*†

A new rapid DNA solution, the RapidHIT^®ID, can accommodate two different sample cartridges, ACE, for the analysis of a single swab and EXT, for the analysis of DNA extracts. An efficient internal validation designed for low‐throughput rapid DNA is described. An evaluation of the EXT sample cartridge is also described. Each cartridge generated profiles with sufficient data quality to meet CODIS eligibility in fewer than 120 min. The results exhibited 100% correlation when compared to conventional DNA typing methods. Precision, reproducibility, stochastic, mixture, and contamination experiments produced expected results. Sensitivity of the ACE sample cartridge was acceptable for buccal swab analysis. The sensitivity of the EXT sample cartridge is discussed. The ACE validation and the EXT evaluation utilized a minimalist, cost‐saving, efficient design to generate a validated RapidHIT^®ID instrument capable of producing genetic profiles from both extracted forensic DNA samples and buccal swab samples within 120 min.     

Prevalence and impact of PCR artifacts from soil samples using the Applied Biosystems™ GlobalFiler™ PCR amplification kit: Interference of non-human artifacts in DNA profiles from a homicide investigation

Non-human artifacts have been observed in a range of forensic typing methods. This is primarily due to the condition and potential environmental contamination of many evidentiary samples. Here, a case example of non-human artifact peaks is presented to illustrate ways in which to recognize potential artifact peaks as well as mitigate their effect on interpretation.     

Predicting Initiator and Near Repeat Events in Spatiotemporal Crime Patterns: An Analysis of Residential Burglary and Motor Vehicle Theft

Near repeat analysis has been increasingly used to measure the spatiotemporal clustering of crime in contemporary criminology. Despite its predictive capacity, the typically short time frame of near repeat crime patterns can negatively affect the crime prevention utility of near repeat analysis. Thus, recent research has argued for a greater understanding of the types of places that are most likely to generate near repeat crime patterns. The current study contributes to the literature through a spatiotemporal analysis of residential burglary and motor vehicle theft in Indianapolis, IN. Near Repeat analyses were followed by multinomial logistic regression models to identify covariates related to the occurrence of initiator (the first event in a near repeat chain) and near repeat (the subsequent event in a near repeat chain) events. The overall findings provide additional support for the argument that neighborhood context can influence the formation and context of spatiotemporal crime patterns.