Project description:<p>Residues from ancient artifacts can help identify which plant species were used for their psychoactive properties, providing important information regarding the deep-time co-evolutionary relationship between plants and humans. However, relying on the presence or absence of one or several biomarkers has limited the ability to confidently connect residues to particular plants. We describe a comprehensive metabolomics-based approach that can distinguish closely related species and provide greater confidence in species use determinations. An approximately 1430-year-old pipe from central Washington State not only contained nicotine, but also had strong evidence for the smoking of <em>Nicotiana quadrivalvis</em> and <em>Rhus glabra</em>, as opposed to several other species in this pre-contact pipe. Analysis of a post-contact pipe suggested use of different plants, including the introduced trade tobacco, <em>Nicotiana rustica</em>. Ancient residue metabolomics provides a new frontier in archaeo-chemistry, with greater precision to investigate the evolution of drug use and similar plant-human co-evolutionary dynamics.</p>
Project description:A small, shed antler fragment of a reindeer from Sjælland, Denmark has been dated to the Mid-Holocene, ca., 4700 cal B.C. Reindeer was an important component of the Lateglacial fauna in Denmark, and the species survived for ca. 1400 years into the Holocene. However, we consider it highly unlikely that this species inhabited Denmark during the Mid-Holocene, when dense forests characterized the vegetation and summer temperatures were somewhat higher than at present. We suggest that the reindeer antler came to Sjælland from Norway or Sweden as a result of trade, perhaps involving flint.
Project description:Teeth are a well-known source of information for paleoanthropologists. Here, we established the ancient dental metaproteomes in several samples from historic sites. The shotgun metaproteomics analysis relies on a iterative search strategy for the identification of the proteins and their origins.
Project description:Teeth are a well-known source of information for paleoanthropologists. Here, we established the ancient dental metaproteomes in several samples from historic sites. The shotgun metaproteomics analysis relies on a iterative search strategy for the identification of the proteins and their origins.
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:In the social amoebae (Dictyostelia) quorum sensing system mediates aggregation of single cells into multicellular aggregates by chemotactic movement towards gradients of diffusible molecules known as acrasins. The acrasin of P. violaceum is the unusual dipeptide N-propionyl-gamma-L-glutamyl-L-ornithine-delta-lactam-ethylester, known as glorin. Phylogenetic analysis has indicated that P. violaceum is more related to the most derived group 4 dictyostelids than to the ancient group 2 polysphondylids such as P. pallidum. Nevertheless it has been reported that P. pallidum cells respond to glorin in chemotaxis assays. This has led to the assumption that glorin-based communication may be the most ancient form of intercellular communication that Dictyostelia invented to organize early steps of multicellular development. In this study we show that glorin mediates rapid changes in gene expression at the transition from vegetative growth to aggregation, apparently without pronounced cross-talk with the cyclic AMP-based communication system that coordinates post-aggregation events in this species. We describe glorin-mediated changes in gene expression in the social amoeba Polysphondylium pallidum at the transition from unicellular growth to multicellular development. Comparison of gene expression in growing cells versus cells starving for 2 or 3 hours in the presence or absence of glorin.