Project description:Analyses of ancient DNA typically involve sequencing the surviving short oligonucleotides, and aligning to genome assemblies from related, modern species. Here, we report that skin from a female woolly mammoth (†Mammuthus primigenius) which died 52,000 years ago retained its ancient genome architecture. We use PaleoHi-C to map chromatin contacts and assemble its genome, yielding twenty-eight chromosome-length scaffolds. Chromosome territories, compartments, loops, Barr bodies, and inactive-X chromosome (Xi) superdomains persist. The active and inactive genome compartments in mammoth skin more closely resemble Asian elephant skin than other elephant tissues. Our analyses uncover new biology. Differences in compartmentalization reveal genes whose transcription was potentially altered in mammoths vs. elephants. Mammoth Xi has a tetradic architecture, not bipartite like human and mouse. We hypothesize that, shortly after this mammoth’s death, the sample spontaneously freeze-dried in the Siberian cold, leading to a glass transition that preserved subfossils of ancient chromosomes at nanometer scale.
Project description:In recent years, sediments from cave environments have provided invaluable insights into ancient hominids, as well as past fauna and flora. Unfortunately, locations with favourable conditions for ancient DNA (aDNA) preservation in sediments are scarce. In this study we analysed a set of samples obtained from sediments adhered to different human skeletal elements, originating from Neolithic to Medieval sites in England, and performed metagenomics and metaproteomics analysis. From them, we were able to reconstruct a partial human genome. The genetic profile of those human sequences matches the one recovered from the original skeletal element. Additionally, aDNA sequences matching the genomes of endogenous gut and oral microbiome bacteria were identified. We also found the presence of genetic sequences corresponding to animals and plants. In particular we managed to retrieve the partial genome and proteome of a Black Rat (Rattus rattus), sharing close genetic affinities to other medieval Rattus rattus. Our results demonstrate that material usually discarded, as it is sediments adhering to human remains, can be used to get a glimpse of the environmental conditions at the time of the death of an individual.
Project description:The identity of most functional elements in the mammalian genome and the phenotypes they impact are unclear. Here, we perform a genome-wide comparative analysis of patterns of accelerated evolution in species with highly distinctive traits to discover candidate functional elements for clinically important phenotypes. We identify accelerated regions (ARs) in the elephant, hibernating bat, orca, dolphin, naked mole rat and thirteen-lined ground squirrel lineages in mammalian conserved regions, uncovering ~33,000 elements that bind hundreds of different regulatory proteins in humans and mice. ARs in the elephant, the largest land mammal, are uniquely enriched at elephant DNA damage response genes and changed conserved regulatory sites. The genomic hotspot for elephant ARs is the E3 ligase subunit of the Fanconi Anemia Complex, a master regulator of DNA repair. Additionally, ARs in the six species are associated with specific human clinical phenotypes that have apparent concordance with overt traits in each species.
Project description:Paget disease of bone (PDB) is a chronic skeletal disorder with contemporary cases characterised by one or a few affected bones in individuals over 55 years of age. PDB-like changes have been noted in archaeological remains as old as Roman although accurate diagnoses and knowledge of the natural history of ancient forms of the disease are lacking. Previous macroscopic and radiographic analyses of six skeletons from a collection of 130 excavated at Norton Priory in Cheshire, UK, and dating to late Medieval times, noted unusually extensive pathological changes resembling PDB affecting up to 75% of individual skeletons. Here we report the prevalence of the disease in the collection is also remarkably high (at least 15.8% of the adult sample) with age-at-death estimations as low as 35 years. Despite these profound phenotypic differences paleoproteomic analyses identified SQSTM1/p62 (p62), a protein central to the pathological milieu of classical PDB, as one of the few non-collagenous human sequences preserved in skeletal samples, indicating that the disorder was likely an ancient precursor of contemporary PDB. Western blotting indicated abnormal migration of ancient p62 protein, with subsequent targeted proteomic analyses detecting more than 60% of the p62 primary sequence and directing sequencing analyses of ancient DNA that excluded contemporary PDB-associated SQSTM1 mutations. Together our observations indicate the ancient p62 protein is likely modified within its C-terminal ubiquitin-associated (UBA) domain. Ancient miRNAs were also remarkably well preserved in an osteosarcoma from a skeleton with extensive disease, with miR-16 expression changes consistent with that reported in contemporary PDB-associated bone tumours. Our work demonstrates the potential of proteomics to inform diagnoses of ancient disease and supports the proposal that Medieval Norton Priory was a ‘hotspot’ for an ancient form of PDB, with unusual features presumably potentiated by as yet unidentified environmental or genetic factors.
2019-04-09 | PXD011743 | Pride
Project description:Comparing ancient DNA preservation in petrous bone and tooth cementum
Project description:In the context of human evolution, the study of proteins may overcome the limitation of the high degradation of ancient DNA over time for providing biomolecular information useful to precise the phylogeny of hominid taxa. Here, we have analysed and compared the tooth proteome of five extant primates (human, gorilla, chimpanzee, orangutan and baboon) using a shotgun proteomics approach. Twenty five proteins were shared by the five datasets, and may be considered as the most representative tooth proteins with a chance of being retrieved from older samples. Some of them were identified by peptides specific to the species, thus allowing to draw up a combinatory panel of peptides with species signature that could be helpful for the taxonomic characterization of ancient samples