Project description:Archaeological materials are a finite resource, and efforts should be made to minimize destructive analyses. This can be achieved by using protocols combining extraction of several lines of evidence, which decreases the material needed for analyses while maximizing the information yield. Archaeological dental calculus is a source of several different types of biomolecules, as well as microfossils, and can tell us about the human host, microbiome, diet, and even occupational activities. Here, we present a unified protocol allowing for simultaneous extraction of DNA and proteins from archaeological dental calculus. We evaluate the protocol on dental calculus from a range of ages and estimated preservation states, and compare it against standard DNA-only and protein-only protocols. We find that most aspects of downstream analyses are unaffected by the unified protocol, although minor shifts in the recovered proteome can be detected. Protein recovery depends on both the amount of starting material and choice of extraction protocol, whereas DNA recovery is significantly lowered through the unified protocol. However, DNA recovery from dental calculus is generally very high, and we found no differences in DNA fragment characteristics or taxonomic profile. In conclusion, the unified protocol allows for simultaneous extraction of two complementary lines of evidence from archaeological dental calculus without compromising downstream analyses, thereby minimizing the need for destructive analysis of this finite resource.
Project description:Archaeological dental calculus has emerged as a rich source of ancient biomolecules, including proteins. Previous analyses of proteins extracted from ancient dental calculus revealed the presence of the dietary milk protein β-lactoglobulin, providing direct evidence of dairy consumption in the archaeological record. However, the potential for calculus to preserve other food-related proteins has not yet been systematically explored. Here we analyse shotgun metaproteomic data from 100 archaeological dental calculus samples ranging from the Iron Age to the post-medieval period (8thC BC - 19thC AD) in Britain, as well as dental calculus from contemporary dental patients and recently deceased individuals, to characterise the range and extent of dietary proteins preserved in dental calculus. In addition to milk proteins, we detected proteomic evidence of foodstuffs such as cereals and plant products, as well as the digestive enzyme salivary amylase. We discuss the importance of optimized protein extraction methods, data analysis approaches, and authentication strategies in the identification of dietary proteins from archaeological dental calculus. Our ability to detect dietary proteins, although limited, demonstrates the potential of these methods to robustly identify foodstuffs in the archaeological record that are under-represented due to their poor preservation.
Project description:Mineralised dental plaque (calculus) has proven to be an excellent source of ancient biomolecules. In this study we present a Mycobacterium leprae genome (6.6-fold), the causative agent of leprosy, recovered via shotgun sequencing of 16th century human dental calculus from an individual from Trondheim, Norway. Moreover, ancient mycobacterial peptides were retrieved via mass spectrometry-based proteomics, further validating the presence of the pathogen. M. leprae can readily be detected in the oral cavity and associated mucosal membranes, which likely contributed to it being incorporated into this individual’s dental calculus. This individual showed some possible, but not definitive, evidence of skeletal lesions associated with early stage leprosy. This study is the first known example of successful multi-omics retrieval of M. leprae from archaeological dental calculus. Furthermore, we offer new insights into dental calculus as an alternative sample source to bones or teeth for detecting and molecularly characterizing M. leprae in individuals from the archaeological record.
Project description:This study investigated the consumption of milk products in the archaeological record, utilizing human dental calculus as a reservoir of dietary proteins from archaeological samples from across Eurasia. Protein extraction and generation of tryptic peptides from dental calculus was performed using a filter-aided sample preparation (FASP) protocol, modified for ancient samples, on 92 samples of archaeological dental calculus. Samples were extracted at three laboratories; the Functional Genomics Centre Zürich (FGCZ), the Centre for GeoGenetics at the National History Museum of Denmark, and BioArCh at the University of York. Sample extracts were sequenced (LC-MS/MS) using an LTQ-Orbitrap Velos (FGCZ), a Q-Exactive Hybrid Quadrupole Orbitrap and an LTQ-Orbitrap Elite (Central Proteomics Facility, Target Discovery Institute, Oxford).
Project description:This study investigated the consumption of milk products in the archaeological record, utilizing human dental calculus as a reservoir of dietary proteins from archaeological samples from across Eurasia. Protein extraction and generation of tryptic peptides from dental calculus was performed using a filter-aided sample preparation (FASP) protocol, modified for ancient samples, on 92 samples of archaeological dental calculus. Samples were extracted at three laboratories; the Functional Genomics Centre Zürich (FGCZ), the Centre for GeoGenetics at the National History Museum of Denmark, and BioArCh at the University of York. Sample extracts were sequenced (LC-MS/MS) using an LTQ-Orbitrap Velos (FGCZ), a Q-Exactive Hybrid Quadrupole Orbitrap and an LTQ-Orbitrap Elite (Central Proteomics Facility, Target Discovery Institute, Oxford).