Evaluierung frühdiagenetischer Veränderungen an Knochenmaterial zur Validierung der Daten gewonnen aus der Analyse stabiler Isotope leichter Elemente

Degradationsbedingte, postmortale Veränderung der isotopischen Zusammensetzung des Knochengewebes stellen ein Problem für die archäometrische Forschung dar, da sie, wenn sie nicht erkannt werden, zu einer potenziellen Datenverzerrung für historische Fragestellungen führen können. Inhalt der Dissertation war daher die Überprüfung der Eignung bestehender Qualitätskriterien zur Anzeige der Integrität der in vivo erworbenen Isotopensignaturen der leichten Elemente C, N und O sowie die Etablierung besser geeigneter Verfahren zur Qualitätskontrolle. Dafür war eine umfassende Analyse diagenetischer Vorgänge im Knochen und deren möglichst genaue Charakterisierung notwendig. Besonderes Augenmerk lag dabei auf der Phase der Frühdiagenese nach kurzen Liegezeiten. Hierfür wurden frische menschliche Proben unter kontrollierten Bedingungen künstlich degradiert, indem sie zum einen rein hydrolytisch geschädigt und zum anderen mit aeroben bzw. anaeroben Mikroorganismen angeimpft wurden. Demgegenüber wurden unter natürlichen Bedingungen degradierte Knochenproben untersucht. Dabei handelte es sich um Knochen eines modernen Friedhofs mit kurzen bis sehr kurzen Liegezeiten sowie diverse archäologische Knochen. Als Vergleichskollektiv wurde ferner die Dekomposition unbestatteter Rehkadaver untersucht. Es zeigte sich im experimentellen Kontext, dass die hydrolytische und mikrobielle Degradation jeweils charakteristische Muster aufwies, welche mit der Diagenese in situ in Einklang gebracht werden konnten. Als entscheidend erwies sich der Einfluss der Weichgewebsdekomposition auf den weiteren Knochenerhalt. Hinsichtlich der Qualitätskriterien für die Anzeige postmortal modifizierter Isotopenwerte des Gewebes konnten sowohl für die organische als auch für die anorganische Knochenfraktion anhand systematischer Untersuchungen bestehende Marker verfeinert bzw. neue Kriterien identifiziert werden

United in death-related by blood? Genetic and archeometric analyses of skeletal remains from the neolithic earthwork bruchsal-aue

Objectives: Straight next to a segment of the outer ditch of the Late Neolithic Michelsberg Culture earthwork of Bruchsal-Aue in SW-Germany (ca. 4250–3650 calBC), a multiple burial of eight individuals (two male adults and six children) plus a subsequent child burial was excavated. In this study, we applied a multidisciplinary approach to elucidate interpersonal relationships and life histories within this collective. Materials and methods: To determine the identity of this collective, we performed aDNA analyses in addition to osteological examination using HVR I plus Y-chromosomal and autosomal STR profiling to find evidence for kinship relations. Strontium isotopic analyses were used to reconsider migrational behavior. To find evidence for a specific social affiliation, the individual diet was reconstructed by performing nitrogen and carbon isotopic analyses. Furthermore, radiocarbon-dating was carried out to integrate the burial context into an absolute timeframe. Two nearby single burials were included in the analyses for comparison. Results: Because of a shared HVR I haplotype, three pairs of individuals were most likely linked by kinship, and statistical testing on autosomal STR profiles shows a high probability for the pair of two men being brothers. Although it cannot be excluded, isotopic data gave no clear proof for migration. A rather poor health status is indicated by skeletal stress markers even though the isotope data attest to a diet rich in meat and fish. Discussion: Although clear kinship relations among the infants remain unconfirmed, a relationship could also be indicated by the positioning of the bodies in the burial pit. Whereas a common cause of death might have been the presupposition for their special treatment, interpersonal relationships were likely the decisive factor for the multiple burial

Strategy for Sensitive and Specific Detection of <i>Yersinia pestis</i> in Skeletons of the Black Death Pandemic

<div><p><i>Yersinia pestis</i> has been identified as the causative agent of the Black Death pandemic in the 14^th century. However, retrospective diagnostics in human skeletons after more than 600 years are critical. We describe a strategy following a modern diagnostic algorithm and working under strict ancient DNA regime for the identification of medieval human plague victims. An initial screening and DNA quantification assay detected the <i>Y. pestis</i> specific <i>pla</i> gene of the high copy number plasmid pPCP1. Results were confirmed by conventional PCR and sequence analysis targeting both <i>Y. pestis</i> specific virulence plasmids pPCP1 and pMT1. All assays were meticulously validated according to human clinical diagnostics requirements (ISO 15189) regarding efficiency, sensitivity, specificity, and limit of detection (LOD). Assay specificity was 100% tested on 41 clinically relevant bacteria and 29 <i>Y. pseudotuberculosis</i> strains as well as for DNA of 22 <i>Y. pestis</i> strains and 30 previously confirmed clinical human plague samples. The optimized LOD was down to 4 gene copies. 29 individuals from three different multiple inhumations were initially assessed as possible victims of the Black Death pandemic. 7 samples (24%) were positive in the pPCP1 specific screening assay. Confirmation through second target pMT1 specific PCR was successful for 4 of the positive individuals (14%). A maximum of 700 and 560 copies per µl aDNA were quantified in two of the samples. Those were positive in all assays including all repetitions, and are candidates for future continuative investigations such as whole genome sequencing. We discuss that all precautions taken here for the work with aDNA are sufficient to prevent external sample contamination and fulfill the criteria of authenticity. With regard to retrospective diagnostics of a human pathogen and the uniqueness of ancient material we strongly recommend using a careful strategy and validated assays as presented in our study.</p> </div

qPCR targeting <i>Y. pestis pla</i> gene screening ancient samples.

<p>qPCR targeting <i>Y. pestis pla</i> gene screening ancient samples.</p

Schematic workflow for the proceeding through highly optimized and validated protocols for the detection of <i>Y. pestis</i> from ancient samples.

<p>Schematic workflow for the proceeding through highly optimized and validated protocols for the detection of <i>Y. pestis</i> from ancient samples.</p

Amino acid profile of specimen MP 59-I, channel 1 (570 nm) and 2 (440 nm).

<p>The profile represents a typical collagenous pattern with a high amino acid yield. However, aspartic and glutamic acid concentrations are significantly reduced. At 72 min an unidentified peak was detected that did not show up in the other samples. </p