首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in order to evaluate the distribution of mitochondrial DNA (mtDNA) heteroplasmy amongst the hairs of an individual who displays point heteroplasmy in blood and buccal cells. A second aim of the exercise was to study reproducibility of mtDNA sequencing of hairs between laboratories using differing chemistries, further to the first mtDNA reproducibility study carried out by the EDNAP group. Laboratories were asked to type 2 sections from each of 10 hairs, such that each hair was typed by at least two laboratories. Ten laboratories participated in the study, and a total of 55 hairs were typed. The results showed that the C/T point heteroplasmy observed in blood and buccal cells at position 16234 segregated differentially between hairs, such that some hairs showed only C, others only T and the remainder, C/T heteroplasmy at varying ratios. Additionally, differential segregation of heteroplasmic variants was confirmed in independent extracts at positions 16093 and the poly(C) tract at 302-309, whilst a complete A-G transition was confirmed at position 16129 in one hair. Heteroplasmy was observed at position 16195 on both strands of a single extract from one hair segment, but was not observed in the extracts from any other segment of the same hair. Similarly, heteroplasmy at position 16304 was observed on both strands of a single extract from one hair. Additional variants at positions 73, 249 and the HVII poly(C) region were reported by one laboratory; as these were not confirmed in independent extracts, the possibility of contamination cannot be excluded. Additionally, the electrophoresis and detection equipment used by this laboratory was different to those of the other laboratories, and the discrepancies at position 249 and the HVII poly(C) region appear to be due to reading errors that may be associated with this technology. The results, and their implications for forensic mtDNA typing, are discussed in the light of the biology of hair formation.  相似文献   

2.
Recently, there has been much debate about what kinds of genetic markers should be implemented as new core loci that constitute national DNA databases. The choices lie between conventional STRs, ranging in size from 100 to 450 bp; mini-STRs, with amplicon sizes less than 200 bp; and single nucleotide polymorphisms (SNPs). There is general agreement by the European DNA Profiling Group (EDNAP) and the European Network of Forensic Science Institutes (ENFSI) that the reason to implement new markers is to increase the chance of amplifying highly degraded DNA rather than to increase the discriminating power of the current techniques. A collaborative study between nine European and US laboratories was organised under the auspices of EDNAP. Each laboratory was supplied with a SNP multiplex kit (Foren-SNPs) provided by the Forensic Science Service, two mini-STR kits provided by the National Institute of Standards and Technology (NIST) and a set of degraded DNA stains (blood and saliva). Laboratories tested all three multiplex kits, along with their own existing DNA profiling technique, on the same sets of degraded samples. Results were collated and analysed and, in general, mini-STR systems were shown to be the most effective. Accordingly, the EDNAP and ENFSI working groups have recommended that existing STR loci are reengineered to provide smaller amplicons, and the adoption of three new European core loci has been agreed.  相似文献   

3.
4.
Y-chromosome linked short tandem repeat (STR) loci are inherited as a closely linked haplotype, which appears to remain stable in a given paternal lineage over many generations. In forensic cases, Y-linked STRs are particularly useful for the identification of human remains as well as in rape cases with mixed male/female stain samples. DYS385 is derived from tandemly duplicated segments of the Y chromosome thus giving rise to two fragments of variable length which do not behave like alleles but genotypes. The European DNA Profiling (EDNAP) group has carried out a collaborative exercise among 14 participating laboratories using DYS385 for typing of five unknown bloodstains and a control sample. Furthermore, population data from eight different European countries with samples sizes between 91 and 150 male individuals were collected. The results confirm previous observations that DYS385 is one of the most informative Y-linked STR loci. It could also be demonstrated that reproducible results can be obtained independently from the electrophoretic separation and detection methods used. Thus DYS385 may serve as a useful complementation to the routinely used autosomal STR systems in special cases.  相似文献   

5.
We have analyzed variation of the mitochondrial DNA (mtDNA) hypervariable segments I and II (HVS-I and HVS-II) in 185 randomly chosen individuals from Korea to provide an expanded and reliable Korean database. Combined sequence comparison of HVS-I and HVS-II led to the identification of 167 different haplotypes characterized by 154 variable sites. One hundred and fifty-one of the haplotypes were individual-specific, 14 were found in two individuals and 2 were found in three individuals. A pairwise comparison of the 185 HVS-I/II sequences found an average of 10.11 +/- 4.63 differences between individuals. The random match probability and gene diversity for the combined hypervariable regions were estimated at 0.66% and 0.9988, respectively. Analyzing the expanded database including three previously reported data sets and the present data using haplogroup-based comparisons and comparison with closely related sequences allowed errors to be detected and eliminated, thus considerably improving data quality. Sample division comparisons based on PhiST genetic distance measures revealed no significant population differentiation in the distribution of mtDNA sequence variations between the present data set and a database in The Scientific Working Group on DNA Analysis Methods (SWGDAM), but did indicate differences from other sets of data. Based on the results of mtDNA profiles, almost all of the mtDNA types studied here could be classified into subsets of haplogroups common in east Asia, and show that the Koreans possess lineages from both the southern and the northern haplogroup complexes of east Asian populations. The new data, combined with other mtDNA sequences, demonstrate how useful comparison with closely related mtDNA sequences can be for improving database quality, as well as providing haplotype information for forensic and population genetic analyses in the Korean population.  相似文献   

6.
We have analyzed the two hypervariable regions HVS-I and HVS-II of 200 Finnish male individuals for forensic purposes. The distribution of the haplotypes within Finland was determined by the geographical knowledge of the donors' maternal ancestors. In our population sample, we identified 135 different mtDNA haplotypes. Different mtDNA sequences were further divided to haplogroups using the EMPOP software. The most common haplogroups were H (40.0%) and U (27.5%). Subgroup U5b, which contains earlier described "Saami motif", consisted majority (65.5%) of the sample in the U haplogroup. Analysis of the mtDNA sequence hypervariable regions I and II showed that the mtDNA diversity within the Finnish population sample was comparable to other European populations and uniformly distributed. This is contrary to the Y-STR "minimal haplotype" diversity, which in Finland is lower than in any of the other European populations studied so far.  相似文献   

7.
Mitochondrial DNA (mtDNA) sequence variations at hypervariable regions HVI, HVII and HVIII were analysed in 100 unrelated Italians from Bologna. The values of the statistical parameters are in agreement with the range of European populations. We suggest that the less informative HVIII region may be useful to distinguish HVI-HVII identical sequences in forensic analysis especially when nuclear DNA cannot be investigated.  相似文献   

8.
A total of 28 laboratories (labs) submitted results for the 1998 collaborative exercise and the proficiency testing program of the Spanish and Portuguese Working Group of the International Society for Forensic Genetics (GEP-ISFG) group. This number increased to 46 labs in 1999. Six bloodstains were submitted, each one with 200 microl soaked in cotton except the sample no. 6 submitted for DNA quantification which had 2 microl. One of the samples was a mixed stain. A paternity testing case and a criminal case in the 1998 trial (GEP'98) and two paternity testing cases in 1999 (GEP'99) were included and the statistical evaluation of the evidence was requested in both cases. In the GEP'99 trial, a theoretical paternity testing case was included. A total of 52 DNA genetic markers were used by the participants in the GEP'98 trial, which increased to 101 in GEP'99. Despite this increasing number of participating labs, results remained quite satisfactory. All the labs used PCR-based DNA polymorphisms with an increasing number of markers, obtaining good results. SLPs were used by a decreasing number of labs but the results indicated a good level of expertise despite the different protocols used.Good results were also obtained for mtDNA despite the difficulties presented by the samples due to the presence of length heteroplasmy in some samples in both trials. The detection of heteroplasmy should, however, be improved.Similar conclusions were reached for both, the paternity and the criminal case by all the labs. Common methodologies for the statistical evaluation of the paternity case were used and the paternity index and the probability of paternity (with an a priori value of 0.5) reported by most of the labs. Also, a great uniformity was found in the evaluation of the criminal case despite the lack of a specific hypothesis in the design of the exercise. Some errors in statistical programs or in calculations were detected in a theoretical paternity case included in the GEP'99 trial for statistical analysis.  相似文献   

9.
Forensic scientists working in 12 state or private laboratories participated in collaborative tests to improve the reliability of the presentation of DNA data at trial. These tests were motivated in response to the growing criticism of the power of DNA evidence. The experts' conclusions in the tests are presented and discussed in the context of the Bayesian approach to interpretation. The use of a Bayesian approach and subjective probabilities in trace evaluation permits, in an easy and intuitive manner, the integration into the decision procedure of any revision of the measure of uncertainty in the light of new information. Such an integration is especially useful with forensic evidence. Furthermore, we believe that this probabilistic model is a useful tool (a) to assist scientists in the assessment of the value of scientific evidence, (b) to help jurists in the interpretation of judicial facts and (c) to clarify the respective roles of scientists and of members of the court. Respondents to the survey were reluctant to apply this methodology in the assessment of DNA evidence.  相似文献   

10.
Sequence analysis of the mitochondrial DNA (mtDNA) control region is of central importance for forensic identity testing as well as for studies of human evolution. Here we report the sequencing data of the hypervariable regions I and II from 50 unrelated individuals from a western German population (Rhine area). In regions I and II, 52 and 26 sites of sequence polymorphism, respectively, were noted. Nucleotide substitution rather than insertion/deletion was the majority of variation. The distribution showed a large bias towards transitional changes than transversional changes. Furthermore we investigated uniparental inheritance in seven CEPH families each family with 7–9 maternal descendants. Most maternal relatives shared identical mtDNA sequences. Additionally sequences were compared for father:child pairs and as expected no evidence for paternal transmission of mtDNA was observed. The high variability of mtDNA control region sequences permits utility in forensic identity investigations. The data also indicate that the neomutation rate seems to be very low from one generation to the other.  相似文献   

11.
12.
Conclusion Identifying correctional objectives and evaluative criteria is essential to facilitating smooth operational functioning of the correctional system. Complicating this necessity is the tremendous growth and responsibilities of the correctional system as budgets continue to suffer reductions or stagnations. Traditional evaluative studies producing valuable insights, have yet to, for the most part, move beyond recidivism and incarceration rates as performance indicators. This is due mostly to the fact that criminal justicians — scholars and practitioners — and the general public lack consensus regarding correctional goals. Instead, what we are experiencing is an ambivalence placing an unfair burden upon the correctional system to create and maintain effective rehabilitative programs, devise punitive strategies, and fulfill these countervailing missions with decreased financial resources than in the past (relative to case load). To be sure, wardens and correctional administrators are called upon today to do more with drastically fewer dollars. The correctional system, we argue, given its unique task of incapacitating people, demands that scholars, practitioners, and policymakers combine efforts to develop correctional goals. These goals once defined, however, are not to become fixed static categories. Instead, they must remain flexible and imitate or adapt to social and cultural conditions, which is not to say merely reflect public opinion. Rather, correctional goals must consider legal, normative, and other structural changes affecting the correctional system — as many scholars recognize these variables having greater impact on incarceration (see Christie, 2000; Dilulio, 1993; Garland, 2001). This joint effort should take advantage of research-based knowledge and examples of best practices to identify the good aspects, weed out the bad, and eliminate the ugly in the U.S. penal system. An earlier version of this paper was presented by the first author as part of the Presidential Address to the Southern Criminal Justice Association, September 24, 2003 in Nashville, Tennessee.  相似文献   

13.
In canine population studies for forensics, the mitochondrial DNA is profiled by sequencing the two hyper variable regions, HV1 and HV2 of the control region.In a first effort to create a Belgian population database some samples showed partially poor sequence quality. We demonstrated that a nuclear pseudogene was co-amplified with the mtDNA control region. Using a new combination of primers this adverse result was no longer observed and sequencing quality was improved. All former samples with poor sequence data were reanalyzed. Furthermore, the forensic canine population study was extended to 208 breed and mixed dogs. In total, 58 haplotypes were identified, resulting in an exclusion capacity of 0.92. The profile distribution of the Belgian population sample was not significantly different from those observed in population studies of three other countries.In addition to the total population study 107 Belgian registered pedigree dogs of six breeds were profiled. Per breed, the obtained haplotypes were supplemented with those from population and purebred studies. The combined data revealed that some haplotypes were more or less prominent present in particular dog breeds. The statistically significant differences in haplotype distribution between breeds and population sample can have consequences on mtDNA databasing and matching probabilities in forensics.  相似文献   

14.
Mitochondrial DNA (mtDNA) examinations play an important role in criminal investigations, identification of victims of mass disasters, and association of unidentified remains with family members. Typically, HV1 and HV2 are amplified via polymerase chain reaction (PCR) followed by fluorescent sequencing. While this method produces the highest level of resolution, it is labor intensive and unable to distinguish components of a mixture. Previously, an electrospray-ionization mass spectrometry (ESI-MS) method was described to determine the base composition profile of enzymatically digested PCR amplified fragments derived from the HV1 and HV2 regions. Advantages of ESI-MS compared to sequencing include speed of analysis, automation, and increased sensitivity, while retaining a high degree of resolution. Here, we report the next generation of this method in which a base composition profile is determined from 24 overlapping PCR reactions. Because ESI-MS provides the relative abundance of each component present, this method allows for the quantitative typing of mixtures. This ESI-MS method does not rely on a priori knowledge of variable sites, allowing the capture of private mutations and individual-specific variation. Due to the multiplex design, automation, speed of analysis, and ability to interrogate mixtures, this method provides a powerful and rapid tool for forensic mtDNA examinations.  相似文献   

15.
In response to continuing interest in obtaining reference deoxyribonucleic acid (DNA) analysis data for previously unstudied population groups, blood samples were collected from Punjabi individuals living in East Punjab, India. This first segment of our research is focused on restriction fragment length polymorphism (RFLP) analysis, with future segments anticipated for various polymerase chain reaction (PCR) based techniques. In this study, the samples were subjected to RFLP analysis using HaeIII, followed by hybridization with variable number tandem repeat (VNTR) probes for loci D2S44, D1S7, D10S28, D4S139, D17S79 and D5S110. The band sizes of the resulting patterns were estimated using an FBI imaging system. The resulting data were subjected to statistical analysis for conformity with Hardy-Weinberg expectations, first for the total population of Punjabis, and additionally for the subgroups of Sikhs and Hindus. The loci are highly polymorphic in all sample populations studied. Except for D5S110, there is no evidence for departure from Hardy-Weinberg equilibrium (HWE) for the VNTR loci in the population groups. In addition, there is little evidence of correlation between the alleles at any of the pairs of loci and no evidence of association across the six loci. Finally, the data suggest that a multiple locus VNTR profile would be rare in the Punjabi or either of its subgroups.  相似文献   

16.
中国广东汉族群体mtDNA控制区的多态性   总被引:4,自引:0,他引:4  
目的 探讨线粒体DNA控制区(包括HVⅠ区、HVⅡ区和HVⅢ区)的多态性。方法 采用PCR扩增和末端标记荧光循环测序的方法,对100名广东汉族无关个体进行了序列分析。结果 共观察到147个变异位点,序列变异包括了碱基转换、颠换、插入、缺失等各种类型。其中在HV Ⅰ区(nt16,024~nt16,365)内观察到88个变异位点,91种单倍型,基因多样度为0.9964;在HVⅡ区(nt73~nt340)观察到42个变异位点,67种单倍型,基因多样度为0.9861;在HVⅢ区(nt438~nt574)观察到9个变异位点,15种单倍型,基因多样度为0.8760。联合3个高变区域的序列,可观察到98种单倍型,基因多样度为0.9996。结论 本研究为线粒体DNA在法庭科学中的应用提供了较系统的实验依据。结果还表明,对于mtDNA等单倍型遗传标记,增加其检测范围,可提高该系统的个体识别能力,使其在法庭科学领域充分发挥作用。  相似文献   

17.
The present article first describes the institution of the German Berufsgenossenschaften (BGs, the institutions for statutory accident insurance and prevention) and their mandate. Besides rehabilitation and compensation, these comprise the prevention of occupational accidents and diseases, and work-related hazards. The main focus within the area of mental health is the prevention work, but rehabilitation and compensation within the German social insurance system in general, and with respect to mental health, will also be explained. Furthermore, the prevention-rehabilitation interface will be illustrated and the cooperation with the health insurance institutions will be described. In the second part, selected results of a survey regarding mental health and stress will be presented.  相似文献   

18.
A collaborative study using the multilocus minisatellite DNA probe MZ 1.3 was carried out to investigate segregation information, mutation rate, DNA fragment frequencies as well as band sharing characteristics. The fingerprint patterns of 393 children as well as 694 unrelated individuals were analysed after digestion of DNA with the restriction enzyme HinfI. A mutation rate of 1% per meiosis or 0.04% per band was found with a mean number of 26 bands/individual. It was shown that maternal and paternal fragments are inherited in equal proportions. Population frequencies of restriction fragments demonstrated a distribution with increasing frequencies in the small fragment size range below 10 kb as well as the absence of very common or very rare fragments. Our data can be used to calculate simple exclusion probabilities based on the number of non-maternal bands in the child.  相似文献   

19.
20.
The applicability of mitochondrial DNA (mtDNA) sequencing was investigated for the identification of the following forensically important species of blowflies from southeastern Australia: Calliphora albifrontalis, C. augur, C. dubia, C. hilli hilli, C. maritima, C. stygia, C. vicina, Chrysomya rufifacies, Ch. varipes and Onesia tibialis. All breed in carrion except O. tibialis, which is an earthworm parasitoid. Emphasis was placed on Calliphora species because they predominate among the carrion-breeding blowfly fauna of southern Australia and their immatures are difficult to identify morphologically. A partial sequence of the mitochondrial COII gene was determined for all species and for COI for C. albifrontalis, C. augur, C. dubia and C. stygia only. Five other species of blowflies, Chrysomya albiceps, Ch. rufifacies, Protophormia terraenovae, Lucilia illustris and L. sericata, for which sequence data were already available, were also included. Analysis of the COI and COII sequences revealed abundant phylogenetically informative nucleotide substitutions that could identify blowfly species to species group. In contrast, because of the low level of sequence divergence of sister species, the data could not distinguish among taxa from the same species group, i.e. the species within the C. augur and C. stygia groups. The molecular data support the existing species group separation of the taxa within Calliphora. Because of the speed and accuracy of current nucleotide sequencing technology and the abundant apomorphic substitutions available from mtDNA sequences, this approach, with the analysis of additional taxa and genes, is likely to enable the reliable identification of carrion-breeding blowflies in Australia.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号