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PubMed2001

Pentanucleotide short tandem repeat locus DXYS156 displays different patterns of variations in human populations.

AIM: To establish a database for the pentameric short tandem repeat locus DXYS156 from worldwide populations for routine genotyping in forensic identity testing and evolutionary biology. METHODS: Using polymerase chain reaction with a newly designed primer pair, we analyzed 1,408 male and female samples from 28 populations representing four major geographic groups. RESULTS: We observed 11 different alleles, which we sequenced and used to construct an allelic ladder. CONCLUSION: DXYS156 displays a contrasting pattern of X-linked and Y-linked variation among geographic regions, and between X and Y chromosomes. This complex allele distribution may be forensically useful for the ethnic differentiation of unknown stains.

Alleles↗
PubMed1998

[PCR-based detection of HLA-DQ alpha and polymarker loci and their application in forensic science].

Studies were conducted to evaluate the forensic applicability of multiplex amplification of HLA-DQ alpha and PM loci. These loci could be simultaneously typed by reverse dot blot approach where allele specific oligonucleotide probes were immobilized on a nylon membrane strip. Allele and genotype frequencies for HLA-DQ alpha and PM loci were determined in Chinese Han population. The frequency data can be used in individual identification and paternity test.

Female↗
PubMed2001

[Chinese Hans population study of fluorescent labelled 8 STR multiplex system].

OBJECTIVE: Chinese Hans population study of 8 STR loci was carried out in 350 unrelated individuals. METHODS: The 8 STR loci(vWA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820, D16S539) and a sexual distinction locus Amelogenin, were amplified simultaneously in one PCR reaction tube, the products were separated by electrophoresis with PE-377 DNA sequencer, and analyzed by Genescan analysis software, then the accurate PCR fragment length and designation of genotypes were finished automatically by the sequencer. RESULTS: 63 alleles and 2 sex determination alleles were found in Hans population altogether; the minimum allele frequency in Chinese Hans population at these loci was 0.17%, the maximum was 50.17%; the fragments were 119-327 base pairs long; the TDP of this system reached 99.99999998%; this system inherited steadily, and was accord with Mandel inheritance rule, no gene mutation was found, all loci met Hardy-Weinberg equilibrium, but the frequencies of Hans population differed from those of African-Americans, Caucasion-Americans and Hispanic-Americans. CONCLUSION: This method is good for identification of little amount and degraded DNA samples from blood stain, semen stain mixed with vaginal excretion, hair root, cigarette root, muscle tissue and ancient bone. It can also make a foundation of establishing the National DNA Database.

Alleles↗
PubMed1999

[PCR-based DNA analysis of vWA31A, TH01, F13A01, FESFPS, TPOX and CSF1PO].

The allele and genotype frequencies of 6 tetranucleotide STR loci were investigated in a sample of 132 unrelated individuals from Chinese Han population. The PCR products were analyzed on 6% denaturing PAGE and detected using fluorescently labeled primers in an automated 377 sequencer(PE). All loci meet Hardy-Weinberg equilibrium. There was no random association of alleles among the 6 loci. The allele frequencies were compared with other population databases. Except locus vWA31A, the observed heterozygosity at other 5 loci was significantly lower than that reported in Caucasian and Black population studies. The calculated DP = 0.99999, PE = 0.9708, pM = 1.059 x 10(-5). The allelic frequency data can be used in forensic identification and paternity testing.

Alleles↗
PubMed2003

DNA fingerprinting of mosses.

Our study introduces the use of DNA fingerprinting of clonal plants in combination with phylogenetic and vegetation studies as a prospective forensic tool in criminal investigations. In this homicide case, the bryophyte species found on the suspects were identified as Brachythecium albicans, Calliergonella lindbergii, and Ceratodon purpureus. Colonies of all three species occurred at the crime site. DNA fingerprinting analyses were conducted for B. albicans and C. lindbergii, which were expected to reproduce mainly clonally, unlike C. purpureus, and included samples found on the suspects and samples collected from the crime site and other locations. It was concluded that B. albicans found on the suspects was likely to originate from the crime scene and that the sample of C. lindbergii may also have originated from the same site.

Adult↗
PubMed2003

Rapid quantification and sex determination of forensic evidence materials.

DNA quantification of forensic evidence is very valuable for an optimal use of the available biological material. Moreover, sex determination is of great importance as additional information in criminal investigations as well as in identification of missing persons, no suspect cases, and ancient DNA studies. While routine forensic DNA analysis based on short tandem repeat markers includes a marker for sex determination, analysis of samples containing scarce amounts of DNA is often based on mitochondrial DNA, and sex determination is not performed. In order to allow quantification and simultaneous sex determination on minute amounts of DNA, an assay based on real-time PCR analysis of a marker within the human amelogenin gene has been developed. The sex determination is based on melting curve analysis, while an externally standardized kinetic analysis allows quantification of the nuclear DNA copy number in the sample. This real-time DNA quantification assay has proven to be highly sensitive, enabling quantification of single DNA copies. Although certain limitations were apparent, the system is a rapid, cost-effective, and flexible assay for analysis of forensic casework samples.

Amelogenin↗
PubMed2003

[Distributions of haplotypes for three Y-STR loci in a Tibetan ethnic group of Chinese population by using Y-STR multiplexes].

OBJECTIVE: One multiplex genotyping system was developed in using silver staining with allelic ladders for three Y-chromosome STR markers (DYS434, DYS443, and DYS456), with a view towards the application of rapid and simple genotyping assay methods for DNA profiling. The distributions of haplotypes for three Y-STR loci(DYS434, DYS443, and DYS456) was investigated in a Tibetan ethnic group of Chinese population. METHODS: Allele and haplotype frequencies at these Y-STRs loci(DYS434, DYS443, and DYS456) were analysed by PCR amplification using Y-STR multiplexes, followed by horizontal non-denaturing polyacrylamide gelelec-trophoresis in 101 unrelated males of Tibetan ethnic group in Lasa of China. RESULTS: A total of 31 different haplotypes were found, 16 of them being unique. The haplotype diversity value (which is the same as the discrimination index) calculated from all three loci combined was 0.9481, which is informative. CONCLUSION: The Y-STR multiplexes provide useful information for forensic analysis and paternity tests and can also be of great benefit for providing information not normally available from autosomal DNA systems.

Alleles↗
PubMed1992

Ethnic differentiation at VNTR loci, with special reference to forensic applications.

Allele-rich VNTR loci provide valuable information for forensic inference. Interpretation of this information is complicated by measurement error, which renders discrete alleles difficult to distinguish. Two methods have been used to circumvent this difficulty--i.e., binning methods and direct evaluation of allele frequencies, the latter achieved by modeling the data as a mixture distribution. We use this modeling approach to estimate the allele frequency distributions for two loci--D17S79 and D2S44--for black, Caucasian, and Hispanic samples from the Lifecodes and FBI data bases. The data bases are differentiated by the restriction enzyme used: PstI (Lifecodes) and HaeIII (FBI). Our results show that alleles common in one ethnic group are almost always common in all ethnic groups, and likewise for rare alleles; this pattern holds for both loci. Gene diversity, or heterozygosity, measured as one minus the sum of the squared allele frequencies, is greater for D2S44 than for D17S79, in both data bases. The average gene diversity across ethnic groups when PstI (HaeIII) is used is .918 (.918) for D17S79 and is .985 (.983) for D2S44. The variance in gene diversity among ethnic groups is greater for D17S79 than for D2S44. The number of alleles, like the gene diversity, is greater for D2S44 than for D17S79. The mean numbers of alleles across ethnic groups, estimated from the PstI (HaeIII) data, are 40.25 (41.5) for D17S79 and 104 (103) for D2S44. The number of alleles is correlated with sample size. We use the estimated allele frequency distributions for each ethnic group to explore the effects of unwittingly mixing populations and thereby violating independence assumptions. We show that, even in extreme cases of mixture, the estimated genotype probabilities are good estimates of the true probabilities, contradicting recent claims. Because the binning methods currently used for forensic inference show even less differentiation among ethnic groups, we conclude that mixture has little or no impact on the use of VNTR loci for forensics.

Alleles↗
PubMed2004

STR typing of human DNA from fly larvae fed on decomposing bodies.

In homicides with entomological evidence, it may be important to prove the presumed association of fly larvae to a corpse, especially if it is in doubt whether all maggots used for entomological expertise developed and fed on it. The present study demonstrates for the first time the possibility of analyzing human microsatellite DNA present in the digestive tract of necrophagous larvae that fed on decomposed bodies with a postmortem interval up to four months. The obtained human STR profiles support the association of a maggot to a specific corpse. In addition, the identification of the host species (e.g., animal source like pig) can be achieved by analysis of the cytochrome b gene. Maggots were collected from 13 corpses after various postmortem intervals and STR typing and HVR amplifications were performed using their crop contents. In seven cases, a complete STR profile was established, in two cases, an incomplete set of alleles was obtained, and in four cases, STR typing was not successful. HVR analysis was successful in all cases except one. The time of storage of the maggots and the length of the postmortem interval up to 16 weeks appeared to have no particular influence on the quality of the results.

Animals↗
PubMedDate not supplied

[Polymorphism of the locus DYS438 in the Polish population].

This paper describes polymorphism of a new locus DYS438 in a Polish population sample of 249 males. In an analyzed population sample 5 of 9 alleles, to date identified, were found (6-14). The most frequent allele was 11 with a frequency of 0.5502. In our population bimodal frequency distribution of DYS438 alleles contrary to the other European populations was not observed. The calculated gene diversity value for DYS438 locus is 0.53 and is higher than observed for DYS391, DYS3891, DYS392 i DYS393 and lower than observed for DYS385I/II, DYS19, DYS389II, DYS439 i DYS390 Y-STR loci analyzed to date in our population. Moreover comparison of homogeneity distribution of DYS438 alleles between different populations was analyzed. Very significant statistical differences (p < 0.0000) were observed between our population and three other European population samples (Italy, Portugal, Spain and Denmark).

Adult↗
PubMedDate not supplied

[Polymorphism of the YCAII locus in a Polish population].

This paper describes the polymorphism of a YCAII locus in a Polish population sample of 189 males. In an analyzed population sample 6 of 11 alleles identified to date were found (www.ystr.org). The most frequent allele was 19 with a frequency of 0.4343. The calculated gene diversity value for YCAII locus is 0.62 and possesses a rather moderate discrimination power for loci analyzed in our population to date. Comparison of homogeneity distribution of YCAII alleles between different populations was analyzed. Very significant statistical differences (p<0.0000) were observed between our population and Italian, German, Lithuanian, Latvian and Estonian populations. No statistical differences were observed between the Polish and Slovenian population sample (p=0.40).

Adult↗
PubMedDate not supplied

[Polymorphism of the DXS1062 locus in a Polish population].

This paper presents the results of a population study of a dinucleotide STR marker DXS1062. Blood samples were obtained from unrelated adult individuals (males and females) living in the northern part of Poland. In the analyzed population, 21 different phenotypes and 9 alleles of the DXS1062 locus were found. The alleles were sequenced and used for the construction of an allelic ladder. The nomenclature in accordance with ISFG guidelines was proposed. The most frequent alleles were 20 and 21. Statistical parameters (PR, PM, PD, PIC) showed that the examined system is useful in forensic medicine.

Adult↗
PubMedDate not supplied

[Rare, out-ladder alleles at the STR loci in the population of Upper Silesia].

Among individuals (participants of paternity testing) from the Upper Silesia region rare, out-ladder alleles in four STRs (routinely used in paternity testing) were found. There are alleles: VWA*12 and 21, CSF1PO*16, D13S317*6 and TPOX*5 with the following frequency: 0.0006 and 0.0006, 0.0005, 0.0006 and 0.0005.

DNA Fingerprinting↗
PubMedDate not supplied

[Polymorphism of four X-chromosomal STRs in a population sample of Podlasie (NE Poland)].

Allele frequencies for four X-chromosomal STR were determined in a population sample of 240 unrelated males and females from north-eastern Poland by multiplex PCR and subsequent automated fluorescent detection (ABI 310) using a commercially available multiplex PCR kit (Mentype Argus X-UL). The genotype distributions among the females conformed with HWE for all analysed loci. The analysed quadruplex is a potential extension to a battery of autosomal systems in forensic applications, especially in the investigation of kinship analysis and deficiency cases.

Chromosomes, Human, X↗