Reliable data are crucial for all research fields applying mitochondrial DNA (mtDNA) as a genetic marker. Quality control measures have been introduced to ensure the highest standards in sequence data generation, validation and a posteriori inspection. A phylogenetic alignment strategy has been widely accepted as a prerequisite for data comparability and database searches, for forensic applications, for reconstructions of human migrations and for correct interpretation of mtDNA mutations in medical genetics.
View Article and Find Full Text PDFForensic Sci Int Genet
March 2011
Length heteroplasmy (LH) in mitochondrial (mt)DNA is usually observed in homopolymeric tracts and manifest as mixture of various length variants. The generally used difference-coded annotation to report mtDNA haplotypes does not express the degree of LH variation present in a sample, even more so, it is sometimes difficult to establish which length variants are present and clearly distinguishable from background noise. It has therefore become routine practice for some researchers to call the dominant type, the "major molecule", which represents the LH variant that is most abundant in a DNA extract.
View Article and Find Full Text PDFThe application of quasi-median networks provides an effective tool to check the quality of mtDNA data. Filtering of highly recurrent mutations prior to network analysis is required to simplify the data set and reduce the complexity of the network. The phylogenetic background determines those mutations that need to be filtered.
View Article and Find Full Text PDFForensic Sci Int Genet
March 2011
The analysis of the haploid mitochondrial (mt) genome has numerous applications in forensic and population genetics, as well as in disease studies. Although mtDNA haplotypes are usually determined by sequencing, they are rarely reported as a nucleotide string. Traditionally they are presented in a difference-coded position-based format relative to the corrected version of the first sequenced mtDNA.
View Article and Find Full Text PDFJ Forensic Sci
January 2011
GeneMarker(®) HID was assessed as a software tool for the analysis of forensic short tandem repeat (STR) data and as a resource for analysis of custom STR multiplexes. The software is easy to learn and use, and includes design features that have the potential to reduce user fatigue. To illustrate reliability and accuracy, STR data from both single-source and mixture profiles were analyzed and compared to profiles interpreted with another software package.
View Article and Find Full Text PDFThe occurrence of heteroplasmy and mixtures is technically challenging for the analysis of mitochondrial DNA. More than that, observed mutations need to be carefully interpreted in the light of the phylogeny as mitochondrial DNA is a uniparental marker reflecting human evolution. Earlier attempts to explain the role of mtDNA in cancerous tissues led to substantial confusion in medical genetics mainly due to the presentation of low sequence data quality and misinterpretation of mutations representing a particular haplogroup background rather than being cancer-specific.
View Article and Find Full Text PDFThis manuscript extends on earlier recommendations of the editor of the International Journal of Legal Medicine on short tandem repeat population data and provides details on specific criteria relevant for the analysis and publication of population studies on haploid DNA markers, i.e. Y-chromosomal polymorphisms and mitochondrial DNA.
View Article and Find Full Text PDFAn X-linked myopathy was recently associated with mutations in the four-and-a-half-LIM domains 1 (FHL1) gene. We identified a family with late onset, slowly progressive weakness of scapuloperoneal muscles in three brothers and their mother. A novel missense mutation in the LIM2 domain of FHL1 (W122C) co-segregated with disease in the family.
View Article and Find Full Text PDFPan-American mitochondrial DNA (mtDNA) haplogroup C1 has been recently subdivided into three branches, two of which (C1b and C1c) are characterized by ages and geographical distributions that are indicative of an early arrival from Beringia with Paleo-Indians. In contrast, the estimated ages of C1d--the third subset of C1--looked too young to fit the above scenario. To define the origin of this enigmatic C1 branch, we completely sequenced 63 C1d mitochondrial genomes from a wide range of geographically diverse, mixed, and indigenous American populations.
View Article and Find Full Text PDFBecause of their sensitivity and high level of discrimination, short tandem repeat (STR) maker systems are currently the method of choice in routine forensic casework and data banking, usually in multiplexes up to 15-17 loci. Constraints related to sample amount and quality, frequently encountered in forensic casework, will not allow to change this picture in the near future, notwithstanding the technological developments. In this study, we present a free online calculator named PopAffiliator ( http://cracs.
View Article and Find Full Text PDFForensic Sci Int Genet
June 2011
Mitochondrial DNA (mtDNA) testing in the forensic context requires appropriate, high quality population databases for estimating the rarity of questioned haplotypes. Currently, however, available forensic mtDNA reference databases only include information from the mtDNA control region. While this information is obviously strengthening the foundation upon which current mtDNA identification efforts are based, these data do not adequately prepare the field for recent and rapid advancements in mtDNA typing technologies.
View Article and Find Full Text PDFForensic Sci Int Genet
January 2011
A collaborative exercise on mRNA profiling for the identification of blood was organized by the European DNA Profiling Group (EDNAP). Seven blood samples and one blood dilution series were analyzed by the participating laboratories for the reportedly blood-specific markers HBB, SPTB and PBGD, using different kits, chemistries and instrumentation. The results demonstrate that HBB is expressed abundantly in blood, SPTB moderately and PBGD significantly less.
View Article and Find Full Text PDFWe report the results of an attempt to identify the supposed remains of a famous World War I (WWI) Italian soldier who was killed in battle along the Italian front in 1915. Thanks to the availability of offspring from both paternal and maternal lineage Y-STRs and mtDNA were analysed and both showed a clear exclusion scenario: the remains did not belong to the supposed war hero. This is the first effort of identification of the remains of soldiers who perished during World War I within a multidisciplinary project aimed at the retrieval of historical and cultural aspects linked to WWI, and the systematic study of the remains of soldiers and ultimately their identification.
View Article and Find Full Text PDFIn order to better characterize and understand the mtDNA population genetics of Central Asia, the mtDNA control regions of over 1,500 individuals from Uzbekistan have been sequenced. Although all samples were obtained from individuals residing in Uzbekistan, individuals with direct ancestry from neighboring Central Asian countries are included. Individuals of Uzbek ancestry represent five distinct geographic regions of Uzbekistan: Fergana, Karakalpakstan, Khorezm, Qashkadarya, and Tashkent.
View Article and Find Full Text PDFBackground: The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.
View Article and Find Full Text PDFA widely held hypothesis regarding the thermostability of thermophilic proteins states asserts that, at any given temperature, thermophilic proteins are more rigid than their mesophilic counterparts. Many experimental and computational studies have addressed this question with conflicting results. Here, we compare two homologous enzymes, one mesophilic (Escherichia coli FMN-dependent nitroreductase; NTR) and one thermophilic (Thermus thermophilus NADH oxidase; NOX), by multiple molecular dynamics simulations at temperatures from 5 to 100 degrees C.
View Article and Find Full Text PDFShort tandem repeat (STR) typing has become the standard technique in forensic methodology for the identification of unknown samples. National DNA databases have been established that contain STR genotypes for intelligence purposes. Due to their success, national DNA databases have been growing so fast that the number of advantageous matches may become a logistic problem for the analysts.
View Article and Find Full Text PDFWe investigated the bio-geographic ancestry of Argentineans, and quantified their genetic admixture, analyzing 246 unrelated male individuals from eight provinces of three Argentinean regions using ancestry-sensitive DNA markers (ASDM) from autosomal, Y and mitochondrial chromosomes. Our results demonstrate that European, Native American and African ancestry components were detectable in the contemporary Argentineans, the amounts depending on the genetic system applied, exhibiting large inter-individual heterogeneity. Argentineans carried a large fraction of European genetic heritage in their Y-chromosomal (94.
View Article and Find Full Text PDFBackground: The Affymetrix MitoChip v2.0 is an oligonucleotide tiling array for the resequencing of the human mitochondrial (mt) genome. For each of 16,569 nucleotide positions of the mt genome it holds two sets of four 25-mer probes each that match the heavy and the light strand of a reference mt genome and vary only at their central position to interrogate all four possible alleles.
View Article and Find Full Text PDFBackground: For large scale studies aiming at a better understanding of mitochondrial DNA (mtDNA), sequence variation in particular mt haplogroups (hgs) and population structure, reliable low-cost high-throughput genotyping assays are needed. Furthermore, methods facilitating sensitive mixture detection and relative quantification of allele proportions are indispensable for the study of heteroplasmy, mitochondrial sequence evolution, and mitochondrial disorders. Here the properties of a homogeneous competitive duplex allele specific PCR (ARMS) assay were scrutinized in the light of these requirements.
View Article and Find Full Text PDFAPCs operate frequently under oxidative stress induced by aging, tissue damage, pathogens, or inflammatory responses. Phagocytic cells produce peroxides and free-radical species that facilitate pathogen clearance and can in the case of APCs, also lead to oxidative modifications of antigenic proteins and peptides. Little information is available presently about the consequences of such modifications on the immune response.
View Article and Find Full Text PDFThe immigration of diverse ethnic groups over the past centuries from surrounding countries into Thailand left footprints in the genetic composition of Thai mitochondrial DNA (mtDNA) lineages. The entire mtDNA control region (1,122 bp) was typed in 190 unrelated male volunteers from the northern Thailand province of Chiang Mai following highest quality standards. For a more precise haplogroup classification, selected single nucleotide polymorphisms from the mtDNA coding region were genotyped.
View Article and Find Full Text PDFHighly differentiated CD28(-) effector T cells which accumulate in a variety of diseases and also with increasing age contribute to inflammatory processes, limit immunological space and diversity, and are associated with immunological dysfunction and reduced responses to vaccination. Elimination of CD28(-) T cells has been suggested as a measure for immunological rejuvenation but may lead to the loss of important T cell specificities. Using T cells specific for the immunodominant CMV-derived epitope NLVPMVATV as a model, we show that the same clonotypes are present in CD8(+)CD28(+) naïve/early memory and CD8(+)CD28(-) effector T cells.
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