Project description:The Caucasus, inhabited by modern humans since the Early Upper Paleolithic and known for its linguistic diversity, is considered to be important for understanding human dispersals and genetic diversity in Eurasia. We report a synthesis of autosomal, Y chromosome, and mitochondrial DNA (mtDNA) variation in populations from all major subregions and linguistic phyla of the area. Autosomal genome variation in the Caucasus reveals significant genetic uniformity among its ethnically and linguistically diverse populations and is consistent with predominantly Near/Middle Eastern origin of the Caucasians, with minor external impacts. In contrast to autosomal and mtDNA variation, signals of regional Y chromosome founder effects distinguish the eastern from western North Caucasians. Genetic discontinuity between the North Caucasus and the East European Plain contrasts with continuity through Anatolia and the Balkans, suggesting major routes of ancient gene flows and admixture. 204 samples were analysed with the Illumina platform Human610-Quad v 1.0 and are described herein.
Project description:Receptor-like kinases (RLKs) are key cell signalling components. The rice ARBUSCULAR RECEPTOR-LIKE KINASE 1 (OsARK1) functions during a stage post-arbuscule development in the arbuscular mycorrhizal (AM) association and belongs to an undefined subfamily of RLKs. Our phylogenetic analysis revealed that ARK1 has an ancient paralogue, ARK2. Single ark2 and ark1ark2 double mutants in rice showed a non-redundant AM symbiotic function for OsARK2. Global transcriptomics identified a set of genes co-regulated by the two RLKs suggesting OsARK1 and OsARK2 to orchestrate symbiosis in a common pathway. ARK lineage proteins harbour a newly identified SPARK domain in their extracellular regions which underwent parallel losses in ARK1 and ARK2 in monocots. This protein domain has ancient origins in the green lineage and defines additional overlooked groups of putative cell surface receptors
Project description:The Caucasus, inhabited by modern humans since the Early Upper Paleolithic and known for its linguistic diversity, is considered to be important for understanding human dispersals and genetic diversity in Eurasia. We report a synthesis of autosomal, Y chromosome, and mitochondrial DNA (mtDNA) variation in populations from all major subregions and linguistic phyla of the area. Autosomal genome variation in the Caucasus reveals significant genetic uniformity among its ethnically and linguistically diverse populations and is consistent with predominantly Near/Middle Eastern origin of the Caucasians, with minor external impacts. In contrast to autosomal and mtDNA variation, signals of regional Y chromosome founder effects distinguish the eastern from western North Caucasians. Genetic discontinuity between the North Caucasus and the East European Plain contrasts with continuity through Anatolia and the Balkans, suggesting major routes of ancient gene flows and admixture.
Project description:Genome-wide premortem DNA methylation patterns can be computationally reconstructed from high-coverage DNA sequences of ancient samples. As DNA methylation is more conserved across species than across tissues, and as ancient DNA is typically extracted from bones and teeth, previous works utilizing ancient DNA methylation maps focused on studying evolutionary changes in the skeletal system. Here, we suggest that DNA methylation patterns in one tissue may, under certain conditions, be informative on DNA methylation patterns in other tissues of the same individual. Using the fact that tissue- specific DNA methylation builds up during embryonic development, we identified the conditions that allow for such cross-tissue inference and devised an algorithm that carries it out. We trained the algorithm on methylation data from extant species and reached high precisions of up to 0.92 for validation data sets. We then used the algorithm on archaic humans, and identified more than 1,850 positions for which we were able to observe differential DNA methylation in prefrontal cortex neurons. These positions are linked to hundreds of genes, many of which are involved in neural functions such as structural and developmental processes. Six positions are located in the NBPF gene family, which likely played a role in human brain evolution. The algorithm we present here allows for the examination of epigenetic changes in tissues and cell types that are absent from the paleontological record, and therefore provides new ways to study the evolutionary impacts of epigenetic changes.
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:Detailed investigation of extremely severe pathological conditions present in ancient human skeletons is important because they can illuminate the breadth of potential interactions between humans and disease etiologies in the past. Here, we applied palaeoproteomics to investigate the bacterial pathogenic factors and host defense response to an ancient human skeletal individual with severe oral pathology. This female skeleton, from the Okhotsk period (i.e., 5th–13th century) of northern Japan, poses abnormal deposition of large amounts of dental calculus and oral dysfunction due to severe periodontal disease. A shotgun mass-spectrometry analysis identified 81 human proteins and 15 bacterial proteins from her calculus. Two pathogenic or bio-invasive proteins originating from two of the three “red complex” bacteria, the core species associated with severe periodontal disease in modern humans, as well as additional two bio-invasive proteins of periodont-associated bacteria were identified. Human proteins associated with the defense response system were identified, but their proportion was mostly similar to that reported in ancient and modern human individuals with lower calculus deposition. These results suggest that the bacterial etiology was similar and the host defense response was not necessarily higher in ancient individuals with abnormal deposition of large amounts of dental calculus.