Project description:Anthropogenic nitrogen (N) deposition may affect soil organic carbon (SOC) decomposition, thus affecting the global terrestrial carbon (C) cycle. However, it remains unclear how the level of N deposition affects SOC decomposition by regulating microbial community composition and function, especially C-cycling functional genes structure. We investigated the effects of short-term N addition on soil microbial C-cycling functional gene composition, SOC-degrading enzyme activities, and CO2 emission in a 5-year field experiment established in an artificial Pinus tabulaeformis forest on the Loess Plateau, China.
Project description:To effectively monitor microbial populations in acidic environments and bioleaching systems, a comprehensive 50-mer-based oligonucleotide microarray was developed based on most of the known genes associated with the acidophiles. This array contained 1,072 probes in which there were 571 related to 16S rRNA and 501 related to functional genes. Acid mine drainage (AMD) presents numerous problems to the aquatic life and surrounding ecosystems. However, little is known about the geographic distribution, diversity, composition, structure and function of AMD microbial communities. In this study, we analyzed the geographic distribution of AMD microbial communities from twenty sites using restriction fragment length polymorphism (RFLP) analysis of 16S rRNA genes, and the results showed that AMD microbial communities were geographically distributed and had high variations among different sites. Then an AMD-specific microarray was used to further analyze nine AMD microbial communities, and showed that those nine AMD microbial communities had high variations measured by the number of detected genes, overlapping genes between samples, unique genes, and diversity indices. Statistical analyses indicated that the concentrations of Fe, S, Ca, Mg, Zn, Cu and pH had strong impacts on both phylogenetic and functional diversity, composition, and structure of AMD microbial communities. This study provides insights into our understanding of the geographic distribution, diversity, composition, structure and functional potential of AMD microbial communities and key environmental factors shaping them. This study investigated the geographic distribution of Acid Mine Drainages microbial communities using a 16S rRNA gene-based RFLP method and the diversity, composition and structure of AMD microbial communities phylogenetically and functionally using an AMD-specific microarray which contained 1,072 probes ( 571 related to 16S rRNA and 501 related to functional genes). The functional genes in the microarray were involved in carbon metabolism (158), nitrogen metabolism (72), sulfur metabolism (39), iron metabolism (68), DNA replication and repair (97), metal-resistance (27), membrane-relate gene (16), transposon (13) and IST sequence (11).
Project description:Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient human ancestors and have demonstrated that contemporary humans harbour genetic material from ancient close relatives, the Neanderthals and Denisovans, and that ancient human individuals are often genetically distinct from nearby extant populations whilst also showing affinities with populations from further afield. Across West Eurasia, there is growing genetic evidence of large-scale, dynamic population movements over the period between 10,000 to 2,000 years ago, such that the ancestry across present-day populations is likely to be a mixture of several ancient groups. Whilst these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled, or have been either too regional or global in their outlook. Here, using recently described haplotype-based techniques, we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1500 years are likely to have maintained differentiation amongst groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. 20 individuals from Croatia included as part of an analysis of admixture in West Eurasia
Project description:Microbial exposure during development can elicit long-lasting effects on the health of an individual. However, how microbial exposure in early life leads to permanent changes in the immune system is unknown. Here, we show that the microbial environment alters the setpoint for immune susceptibility by altering the developmental architecture of the CD8+ T cell compartment. In particular, early microbial exposure results in the preferential expansion of highly responsive fetal-derived CD8+ T cells that persist into adulthood and provide the host with enhanced immune protection against intracellular pathogens. Interestingly, microbial education of fetal-derived CD8+ T cells occurs during thymic development rather than in the periphery and involves the acquisition of a more effector-like epigenetic program. Collectively, our results provide a new conceptual framework for understanding how microbial colonization in early life leads to lifelong, and potentially irreversible, changes in the immune system.
Project description:The data set contains MS/MS data on teeth extracts for Ancient DNA teeth samples ran in both positive and Negative ionization modes
Project description:Studies of ancient DNA have revolutionized our understanding of extinct organisms, but thus far the maximum estimated age of sequenced DNA is two million years. However, evidence for endogenous biomolecules, including proteins, lipids, and pigments have been found in much older fossils, dating to up to 195 million years. Amino acid sequence data consistent with ancient, endogenous biomolecules have been derived from specimens of the theropod Tyrannosaurus rex (MOR 1125) and the hadrosaur Brachylophosaurus canadensis (MOR 2598). Histochemical and immunological studies also identified a molecule consistent with DNA in these two ancient specimens, localized to a single point within preserved osteocytes. Here we report the sequencing and analysis of DNA extracted from osteocytes and blood vessels of T. rex and B. canadensis, liberated after demineralization of dense cortical bone. Usable sequence reads were obtained at a low recovery rate. After the removal of high-quality reads that mapped to the human genome, the remaining reads were highly fragmented, with similarities to multiple animal species including reptilian and avian genomes. Our findings support the hypothesis that DNA and histone signal from imaging, mass spectrometry, and DNA sequencing of dinosaur osteocytes are endogenously preserved biomolecules.
Project description:Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient human ancestors and have demonstrated that contemporary humans harbour genetic material from ancient close relatives, the Neanderthals and Denisovans, and that ancient human individuals are often genetically distinct from nearby extant populations whilst also showing affinities with populations from further afield. Across West Eurasia, there is growing genetic evidence of large-scale, dynamic population movements over the period between 10,000 to 2,000 years ago, such that the ancestry across present-day populations is likely to be a mixture of several ancient groups. Whilst these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled, or have been either too regional or global in their outlook. Here, using recently described haplotype-based techniques, we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1500 years are likely to have maintained differentiation amongst groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia.
Project description:Paleofeces are an important source of information to study the evolution of dietary habits and human health. The UNESCO World Heritage region of Hallstatt-Dachstein/Salzkammergut is one of Europe’s oldest cultural and industrial landscapes; its underground salt mines dating back at least to the 14th century BC are one of the few archaeological sites where paleofeces are well preserved. The high salt concentrations and the constant annual temperature at around 8°C inside the isolated Hallstatt mines have perfectly preserved organic archaeological artefacts (e.g. paleofeces, clothing, mining tools) that provide unique insights into the daily life of a progressive community in Hallstatt. Here we subjected human paleofeces dated from the Bronze Age to early Modern Times to an in-depth microscopic, metagenomic and proteomic analysis. This allowed us to reconstruct the diet of the former population and gain insights into their ancient gut microbiome composition. Our dietary survey identified bran and glumes of different cereals as one of the most prevalent plant fragments. This highly fibrous, carbohydrate-rich diet was supplemented with proteins from broad beans and occasionally with fruits, nuts, or animal food. Linked to these traditional dietary habits all ancient miners up to the early Modern times have gut microbiome structures akin to modern non-Westernized individuals which may indicate a shift in the gut community composition of modern Westernized populations due to quite recent dietary and lifestyle changes. When we extended our microbial survey to fungi present in the paleofeces, we observed in one of the Iron Age samples a high abundance of Penicillium roqueforti and Saccharomyces cerevisiae DNA. Genome-wide analysis indicates that both fungi were involved in food fermentation and provide the first molecular evidence for blue cheese and beer consumption during Iron Age Europe.