Detection of the A189G mtDNA heteroplasmic mutation in relation to age in modern and ancient bones.

International audienceThe aim of this study was to demonstrate the presence of the A189G age-related point mutation on DNA extracted from bone. For this, a peptide nucleic acid (PNA)/DNA sequencing method which can determine an age threshold for the appearance of the mutation was used. Initially, work was done in muscle tissue in order to evaluate the sensitivity of the technique and afterwards in bone samples from the same individuals. This method was also applied to ancient bones from six well-preserved skeletal remains. The mutation was invariably found in muscle, and at a rate of up to 20% in individuals over 60 years old. In modern bones, the mutation was detected in individuals aged 38 years old or more, at a rate of up to 1%, but its occurrence was not systematic (only four out of ten of the individuals over 50 years old carried the heteroplasmy). For ancient bones, the mutation was also found in the oldest individuals according to osteologic markers. The study of this type of age-related mutation and a more complete understanding of its manifestation has potentially useful applications. Combined with traditional age markers, it could improve identification accuracy in forensic cases or in anthropological studies of ancient populations

Molecular Identification of Bacteria by Total Sequence Screening: Determining the Cause of Death in Ancient Human Subjects

Research of ancient pathogens in ancient human skeletons has been mainly carried out on the basis of one essential historical or archaeological observation, permitting specific pathogens to be targeted. Detection of ancient human pathogens without such evidence is more difficult, since the quantity and quality of ancient DNA, as well as the environmental bacteria potentially present in the sample, limit the analyses possible. Using human lung tissue and/or teeth samples from burials in eastern Siberia, dating from the end of 17th to the 19th century, we propose a methodology that includes the: 1) amplification of all 16S rDNA gene sequences present in each sample; 2) identification of all bacterial DNA sequences with a degree of identity $95%, according to quality criteria; 3) identification and confirmation of bacterial pathogens by the amplification of the rpoB gene; and 4) establishment of authenticity criteria for ancient DNA. This study demonstrates that from teeth samples originating from ancient human subjects, we can realise: 1) the correct identification of bacterial molecular sequence signatures by quality criteria; 2) the separation of environmental and pathogenic bacterial 16S rDNA sequences; 3) the distribution of bacterial species for each subject and for each burial; and 4) the characterisation of bacteria specific to the permafrost. Moreover, we identified three pathogens in different teeth samples by 16S rDNA sequence amplification: Bordetella sp., Streptococcus pneumoniae and Shigella dysenteriae. We tested for the presence of these pathogens by amplifying the rpoB gene. For the first time, we confirmed sequences from Bordetella pertussis in the lungs of an ancient male Siberian subject, whose grave dated from the end of the 17th century to the early 18th century

Etude d'ADN ancien au niveau de la pulpe dentaire de la série ostéologique de Saint Côme et Damien

International audienceDe nombreuses études soutiennent l’hypothèse de la “non-possibilité” de contamination de pulpes dentaires par de l’ADN exogène ou par des inhibiteurs de la réaction de polymérisation en chaîne. Nous avons étudié les loci STR de 20 dents appartenant à quatre sujets de la série ostéologique de Saint Côme et Damien. L’ADN a été extrait de pulpes dentaires anciennes recueillies après fracture des 20 dents. Nous avons mis en évidence une fragmentation très importante de l’ADN qui inhibe la réaction de polymérisation en chaîne. Cette inhibition a été limitée par dilution des volumes réactionnels des échantillons, nous avons pu mettre alors en évidence des profils alléliques malgré l’extrême dégradation de l’ADN

Etude d'ADN ancien au niveau de la pulpe dentaire de la série ostéologique de Saint Côme et Damien

International audienceDe nombreuses études soutiennent l’hypothèse de la “non-possibilité” de contamination de pulpes dentaires par de l’ADN exogène ou par des inhibiteurs de la réaction de polymérisation en chaîne. Nous avons étudié les loci STR de 20 dents appartenant à quatre sujets de la série ostéologique de Saint Côme et Damien. L’ADN a été extrait de pulpes dentaires anciennes recueillies après fracture des 20 dents. Nous avons mis en évidence une fragmentation très importante de l’ADN qui inhibe la réaction de polymérisation en chaîne. Cette inhibition a été limitée par dilution des volumes réactionnels des échantillons, nous avons pu mettre alors en évidence des profils alléliques malgré l’extrême dégradation de l’ADN

Detection of age-related duplications in mtDNA from human muscles and bones.

International audienceSeveral studies have demonstrated the age-related accumulation of duplications in the D-loop of mitochondrial DNA (mtDNA) extracted from skeletal muscle. This kind of mutation had not yet been studied in bone. The detection of age-related mutations in bone tissue could help to estimate age at death within the context of legal medicine or/and anthropological identification procedures, when traditional osteological markers studied are absent or inefficient. As we detected an accumulation of a point mutation in mtDNA from an older individual's bones in a previous study, we tried here to identify if three reported duplications (150, 190, 260 bp) accumulate in this type of tissue. We developed a sensitive method which consists in the use of back-to-back primers during amplification followed by an electrophoresis capillary analysis. The aim of this study was to confirm that at least one duplication appears systematically in muscle tissue after the age of 20 and to evaluate the duplication age appearance in bones extracted from the same individuals. We found that the number of duplications increase from 38 years and that at least one duplicated fragment is present in 50% of cases after 70 years in this tissue. These results confirm that several age-related mutations can be detected in the D-loop of mtDNA and open the way for the use of molecular markers for age estimation in forensic and/or anthropological identification

PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS

info:eu-repo/semantics/publishe

Collaborative EDNAP exercise on the IrisPlex system for DNA-based prediction of human eye colour

The IrisPlex system is a DNA-based test system for the prediction of human eye colour from biological samples and consists of a single forensically validated multiplex genotyping assay together with a statistical prediction model that is based on genotypes and phenotypes from thousands of individuals. IrisPlex predicts blue and brown human eye colour with, on average, >94% precision accuracy using six of the currently most eye colour informative single nucleotide polymorphisms (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, SLC45A2 (MATP) rs16891982, TYR rs1393350, and IRF4 rs12203592) according to a previous study, while the accuracy in predicting non-blue and non-brown eye colours is considerably lower. In an effort to vigorously assess the IrisPlex system at the international level, testing was performed by 21 laboratories in the context of a collaborative exercise divided into three tasks and organised by the European DNA Profiling (EDNAP) Group of the International Society of Forensic Genetics (ISFG). Task 1 involved the assessment of 10 blood and saliva samples provided on F

Traumatic brain injury : integrated approaches to improve prevention, clinical care, and research

Rahul Raj on työryhmän InTBIR Participants Investigators jäsen.Peer reviewe