单亲案亲权鉴定结果判定策略

目的探讨用STR基因座进行单亲鉴定出现矛盾基因座时下结论的策略。方法根据基因频率和遗传规律,推导单亲案亲权鉴定时的非父排除率。根据平均单亲非父排除率和平均突变率,用二项分布公式分别计算出现不同数目矛盾基因座时真父和假父的概率和似然率(亲权指数)。结果对STR共显性基因座,其单亲非父排除率的计算公式为:PEM=∑i=n1pi2(1-pi)2 ∑i相似文献   

微量DNA的短串联重复序列分型可行性

目的了解微量DNA分型的法医学应用的可行性。方法一系列浓度的DNA模板用PowerPlexTM16System试剂盒扩增,并用ABI377DNA测序仪进行短串联重复序列(STR)的分型。结果当模板量小于250pg时,部分位点发生了等位基因漏扩,并出现非特异带、杂合子扩增不平衡等干扰分型的杂峰。结论上述这些不正常的现象可能会导致分型错误。在对微量检材的DNA检验结果进行判型时一定要小心谨慎,全面考虑。     

牛微卫星的研究现状及在法庭科学中的应用

微卫星标记具有高度灵敏性、高度特异性及操作简便省时的特点,使其在目前的动物遗传标记研究中成为一种应用广泛的分子标记技术。本文就牛微卫星标记的特点、研究现状及其在法庭科学中的应用加以论述,并对前景加以评定。     

Validation of short tandem repeats (STRs) for forensic usage: performance testing of fluorescent multiplex STR systems and analysis of authentic and simulated forensic samples

The amplification and typing conditions for the 13 core CODIS loci and their forensic applicability were evaluated. These loci are CSF1PO, FGA, TH01, TPOX, vWA, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, and D21S11. Results were obtained using the multiplex STR systems AmpFlSTR Profiler Plus and AmpFlSTR COfiler (Applied Biosystems, Foster City, CA), GenePrint PowerPlex (Promega Corporation, Madison, WI), and subsets of these kits. For detection of fluorescently labeled amplified products, the ABI Prism 310 Genetic Analyzer, the ABI Prism 377 DNA Sequencer, the FMBIO II Fluorescent Imaging Device, and the Fluorlmager were utilized. The following studies were conducted: (a) evaluation of PCR parameter ranges required for adequate performance in multiplex amplification of STR loci, (b) determination of the sensitivity of detection of the systems, (c) characterization of non-allelic PCR products, (d) evaluation of heterozygous peak intensities, (e) determination of the relative level of stutter per locus, (f) determination of stochastic PCR thresholds, (g) analysis of previously typed case samples, environmentally insulted samples, and body fluid samples deposited on various substrates, and (h) detection of components of mixed DNA samples. The data demonstrate that the commercially available multiplex kits can be used to amplify and type STR loci successfully from DNA derived from human biological specimens. There was no evidence of false positive or false negative results and no substantial evidence of preferential amplification within a locus. Although at times general balance among loci labeled with the same fluorophore was not observed, the results obtained were still valid and robust. Suggested criteria are provided for determining whether a sample is derived from a single source or from more than one contributor. These criteria entail the following: (a) the number of peaks at a locus, (b) the relative height of stutter products, and (c) peak height ratios. Stochastic threshold levels and the efficiency of non-templated nucleotide addition should be considered when evaluating the presence of mixtures or low quantity DNA samples. Guidelines, not standards, for interpretation should be developed to interpret STR profiles in cases, because there will be instances in which the standards may not apply. These instances include (a) a primer binding site variant for one allele at a given locus, (b) unusually high stutter product, (c) gene duplication, and (d) translocation.     

自动荧光分析法检验陈旧骨骼和牙齿的vWA和LPL位点

为鉴定陈旧骨骼和牙齿的尸源 ,对DNA的提取方法进行了研究,并建立了vWA和LPL位点的自动荧光分析技术,该法简便、快速、有效、可对存放2、3、4、7年的陈旧骨骼和牙齿成功地进行检验,在检验中能直接确定样品的等位基因     

Chelating resin-based extraction of DNA from dental pulp and sex determination from incinerated teeth with Y-chromosomal alphoid repeat and short tandem repeats

A procedure utilizing Chelex 100, chelating resin, was adapted to extract DNA from dental pulp. The procedure was simple and rapid, involved no organic solvents, and did not require multiple tube transfers. The extraction of DNA from dental pulp using this method was as efficient, or more so, than using proteinase K and phenol-chloroform extraction. In this study, the Chelex method was used with amplification and typing at Y-chromosomal loci to determine the effects of temperature on the sex determination of the teeth. The extracted teeth were incinerated in a dental furnace for 2 minutes at 100 degrees C, 200 degrees C, 300 degrees C, 400 degrees C, and 500 degrees C. After the isolation of DNA from the dental pulp by the Chelex method, alphoid repeats, and short tandem repeats, the human Y chromosome (DYZ3), DYS19, SYS389, DYS390, and DYS393 could be amplified and typed in all samples incinerated at up to 300 degrees C for 2 minutes. The DYS389 locus in some samples could not be amplified at 300 degrees C for 2 minutes. An autopsy case is described in which genotypings of DYS19, DYS390, and DYS393 from dental pulp obtained from a burned body were needed. The data presented in this report suggest that Chelex 100-based DNA extraction, amplification, and typing are possible in burned teeth in forensic autopsy cases.     

Personal identification using Y-chromosomal short tandem repeats from bodily fluids mixed with semen

The male-specific, human Y-chromosomal short tandem repeats (Y-STRs) are very useful in forensic analysis. The authors report a sexual crime case in which the direct Y-STR haplotype analysis of several mixtures of various bodily fluids including semen was very effective for identifying the perpetrator of the crime. The typing of three Y-STRs (DYS19, DYS389II, and DYS390) could be detected from the mixed DNA of sperm and female cells in the victim's vagina, vaginal orifice, and anus. These haplotypes originated from one man and matched those of the suspect. Accordingly, the combination of direct extraction of DNA and Y-STR haplotype analysis is considered to be very useful for mixtures of bodily fluids, including semen or other male cells.     

Interrogation of short tandem repeats using fluorescent probes and melting curve analysis: A step towards rapid DNA identity screening

Current forensic DNA profiling methods rely on the analysis of samples at specialised laboratories with an average turnaround time of several days. The ability to rapidly determine a partial profile of short tandem repeats at the point-of-arrest would be of great benefit to police forces around the world, for example enabling a suspect to be rapidly included or excluded from an investigation. We have developed a homogeneous PCR method for the interrogation of STR loci utilising fluorescent oligonucleotide probes and melting curve analysis. Alleles of the D18S51, TH01 and D8S1179 loci were differentiated and identified on the basis of target length and probe melting temperature. Assay performance was evaluated by comparing melting peak data with the AmpFlSTR^® SGM Plus^® system. The method is compatible with direct analysis of unpurified buccal swab samples, enabling a partial STR profile to be generated within 1 h.     

Sequence variation in humans and other primates at six short tandem repeat loci used in forensic identity testing

A large number of alleles from the six different short tandem repeat (STR) loci FGA, D3S1358, vWA, CSF1PO, TPOX and TH01, used in human identity testing were sequenced to provide support for the robustness of fluorescent STR DNA typing by allele size. Sequence information for some of these loci (FGA, vWA, TH01) is an extension of published work, whereas no extensive sequence information is available with respect to the D3S1358, CSF1PO, and TPOX loci. Sequencing of alleles at each locus has provided quantitative data with respect to the true nucleotide length of common alleles, and of alleles that vary in length from the common alleles. All alleles that were identified as "off-ladder" alleles through fluorescent typing at these STR loci have proven to be true length variant alleles. Sequencing at the D3S1358 and CSF1PO loci allowed for the establishment of a common nomenclature for these loci. A correlation between percent stutter and the length of the core tandem repeat is demonstrated at the FGA locus. Alleles in which the core tandem repeat is interrupted by a repeat unit of different sequence have a reduced percent stutter. DNA samples from three non-human primates (chimpanzee, orangutan, and gorilla) were compared to the human sequences, and shown to differ markedly across loci with respect to their homology. The effects of primer binding site mutations on the amplification efficiency at a particular locus, and methods used to interpret amplification imbalance of heterozygous alleles at a locus is also addressed.     

A new pentaplex system to study short tandem repeat markers of forensic interest on X chromosome

A new method has been optimised to amplify five X chromosome short tandem repeat (STR) markers of interest in forensic medicine: human phosphoribosyl transferase (HPRTB), DXS101, androgen receptor (ARA), DXS7423 and DXS8377. Markers were conveniently amplified in a single PCR reaction with fluorochrome-labelled primers, which allowed the analysis of fragment sizes after injection into a capillary electrophoresis system. The most common alleles of each locus were sequenced and used in a control ladder to type unknown samples.     

Y-chromosomal short tandem repeats haplotyping from vaginal swabs using a chelating resin-based DNA extraction method and a dual-round polymerase chain reaction

Reported are 2 autopsy cases in which Y-chromosomal microsatellite short tandem repeats DYS19, DYS389I and II, DYS390, and DYS393 could be haplotyped with vaginal swabs by using a Chelex 100-based DNA extraction method and dual-round polymerase chain reaction. The extraction of DNA from vaginal swabs by using this method was as efficient or more efficient than using proteinase K and phenol-chloroform extraction or the alkaline lysis methods. Y-chromosomal microsatellite short tandem repeats haplotyping based on the dual-round polymerase chain reaction method provided genotypes from all the loci determined. Although amplification of Y-chromosomal microsatellite short tandem repeats loci is not directly involved in the existence of spermatozoa, it is considerably advantageous for male individualization from body fluid mixture stains in criminal cases.     

Population genetic data of eight tetrameric short tandem repeats (STRs) in Casablanca resident population to use in forensic casework

The allele frequencies for eight short tandem repeat (STR) loci HUMvWA, HUMFES/FPS, HUMF13A, HUMF13B, HUMTHO1, HUMTPOX, HUMCSF1P0, HUMLPL included in Geneprint STR kits were obtained from 234 unrelated individuals in Casablanca.     

Maine Caucasian population DNA database using twelve short tandem repeat loci

A population study of Caucasians residing in Maine was conducted using the AmpF1STR Profiler PCR Amplification Kit and the AmpF1STR Profiler Plus PCR Amplification Kit (Applied Biosystems Division (ABD) of Perkin Elmer, Foster City, CA). The kits contain the reagents necessary to amplify 12 different STR loci and the gender marker Amelogenin using two multiplex PCR, each containing nine STR loci. Thus, there is an overlap of six STR loci. The 12 STR loci are TH01, TPOX, CSF1PO, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, and D7S820. These loci represent 12 of the 13 core loci selected by the CODIS STR standardization project. Dye-labeled amplification products were separated and detected using the capillary electrophoresis instrument ABI Prism 310 Genetic Analyzer. Allele frequencies were determined for the 12 STR loci. Statistical analysis of the data included Hardy-Weinburg equilibrium (HWE) analysis, pairwise independence testing, power of discrimination (PD), and probability of exclusion (PE).     

Multiplex DNA typing of short tandem repeat loci on Y chromosome of Chinese population in Taiwan

Allele frequencies and haplotypes for ten Y chromosome STRs loci, namely, DYS19, DYS385 I, DYS385 II, DYS388, DYS389 I, DYS389 II, DYS390, DYS391, DYS392 and DYS393 were obtained from a sample of 582 Chinese individuals in Taiwan.     

Multiplex DNA typing of short tandem repeat loci on Y chromosome of Chinese population in Taiwan

Allele frequencies and haplotypes for ten Y chromosome STRs loci, namely, DYS19, DYS385 I, DYS385 II, DYS388, DYS389 I, DYS389 II, DYS390, DYS391, DYS392 and DYS393 were obtained from a sample of 582 Chinese individuals in Taiwan.     

Rapid and high-throughput forensic short tandem repeat typing using a 96-lane microfabricated capillary array electrophoresis microdevice

A 96-channel microfabricated capillary array electrophoresis (muCAE) device was evaluated for forensic short tandem repeat (STR) typing using PowerPlex 16 and AmpFlSTR Profiler Plus multiplex PCR systems. The high-throughput muCAE system produced high-speed <30-min parallel sample separations with single-base resolution. Forty-eight previously analyzed single-source samples were accurately typed, as confirmed on an ABI Prism 310 and/or the Hitachi FMBIO II. Minor alleles in 3:1 mixture samples containing female and male DNA were reliably typed as well. The instrument produced full profiles from sample DNA down to 0.17 ng, a threshold similar to that found for the ABI 310. Seventeen nonprobative samples from various evidentiary biological stains were also correctly typed. The successful application of the muCAE device to actual forensic STR typing samples is a significant step toward the development of a completely integrated STR analysis microdevice.     

Sequence variation at three X chromosomal short tandem repeats in Caucasian and African populations

Sequence variation for the X chromosome short tandem repeats (X-STRs) DXS9898, DXS6789 and GATA172D05 was studied in two major population groups, namely Caucasians and Africans. DXS6789 revealed two different subtype sequence polymorphisms: for shorter alleles, with less than 17 repeats, results showed a simple composition with the following structure: (TATG)_m-(TATC)_n. For longer alleles, a constant TATC insertion was observed at the beginning of the variable repeat unit. Additionally, alleles identical in size revealed structural variations regarding the TATG/TATC proportion. Africans showed a higher intra-allelic variation at this locus than the Caucasian population group. For all three loci, DXS9898, DXS6789 and GATA172D05, no unique structure was found among Africans and Caucasians.     

Genetic data of 4 X-chromosomal short tandem repeats in a North of Portugal population

POPULATION: One hundred unrelated females and 100 unrelated males, autochthonous, healthy, from the North of Portugal.