Project description:The extreme environments of the Tibetan Plateau offer significant challenges to human survival, demanding novel adaptations. While the role of biological and agricultural adaptations in enabling early human colonization of the plateau has been widely discussed, the contribution of pastoralism is less well understood, especially the dairy pastoralism that has historically been central to Tibetan diets. Here, we analyze preserved proteins from the dental calculus of 40 ancient individuals to report the earliest direct evidence of dairy consumption on the Tibetan Plateau. Our palaeoproteomic results demonstrate that dairy pastoralism began on the higher plateau by approximately 3,500 years ago, more than 2,000 years earlier than the recording of dairying in historical sources. With less than 1% of the Tibetan Plateau dedicated to farmland, pastoralism and the milking of ruminants were essential for large-scale human expansion into agriculturally-marginal regions that make up the majority of the plateau. Dairy pastoralism allowed conversion of abundant grasslands into nutritional human food, which facilitating adaptation in the face of extreme climatic and altitudinal pressures, and maximizing the land area available for long-term human occupation of the “roof of the world”.
Project description:Due to its high altitude and extreme climate conditions, the Tibetan plateau is a region vulnerable to the impact of climate changes and anthropogenic perturbation, thus understanding how its microbial communities function may be of high importance. Here, we report a study to profile soil microbial structural genes, which infers functional roles of microbial communities, aiming to explore potential microbial responses to climate changes and anthropogenic perturbation. Using a microarray-based metagenomics tool named GeoChip 4.0, we showed that microbial communities in treatment site were distinct, compared with those in control site, e.g. shrubland vs grassland, grazing site vs ungrazing site, or warmer site vs colder site. Substantial variations were apparent in stress, N and C cycling genes, but they were in line with the functional roles of these genes.
Project description:The altitude gradient limits the growth and distribution of alpine plants.Alpine plants have developed strategies to survive the extremely cold conditions prevailing at high altitudes; however, the mechanism underlying the evolution of these strategies remains unknown. The alpine plant Potentilla saundersiana is widespread in the Northwestern Tibetan Plateau. In this study, we conducted a comparative proteomics analysis to investigate the dynamic patterns of protein expression of P. saundersiana located at five different altitudes. We detected and functionally characterized 118 differentially expressed proteins. Our study confirmed that increasing levels of antioxidant proteins, and their respective activities, and accumulation of primary metabolites, such as proline and sugar, confer tolerance to the alpine environment in P. saundersiana. Proteins species associated with the epigenetic regulation of DNA stability and post-translational protein degradation were also involved in this process. Furthermore, our results showed that P. saundersiana modulated the root architecture and leaf phenotype to enhance adaptation to alpine environmental stress through mechanisms that involved hormone synthesis and signal transduction, particularly the cross-talk between auxin and strictosidine. Based on these findings, we conclude that P. saundersiana uses multiple strategies to adapt to the high-altitude environment of the Northwestern Tibetan Plateau.
Project description:A dentine sample from a previously unknown hominin specimen deriving from the Tibetan Plateau was analyzed using LC-MS/MS in order to characterize its proteome, protein damage characteristics, and phylogenetic affinities to known Late Pleistocene hominin clades (humans, Neanderthals, Denisovans).
Project description:Tibetan's adaptation to high-altitude environment at the Qinghai-Tibetan plateau represents a remarkable case of natural selection during recent human evolution. We generated time series paired RNAseq, ATACseq and Hi-C data in Tibetan and Han Chinese's umbilical endothelial cells from normoxia to hypoxia condition. Our results provide a broad resource of genome-wide hypoxia regulatory network to characterize the effect of genetic variation in high-altitude adaptation, and indicates large-scale maps of variants need proper cell types to understand its act on gene regulation.
Project description:Tibet is one of the most threatened regions by climate warming, thus understanding how its microbial communities function may be of high importance for predicting microbial responses to climate changes. Here, we report a study to profile soil microbial structural genes, which infers functional roles of microbial communities, along four sites/elevations of a Tibetan mountainous grassland, aiming to explore potential microbial responses to climate changes via a strategy of space-for-time substitution. Using a microarray-based metagenomics tool named GeoChip 4.0, we showed that microbial communities were distinct for most but not all of the sites. Substantial variations were apparent in stress, N and C cycling genes, but they were in line with the functional roles of these genes. Cold shock genes were more abundant at higher elevations. Also, gdh converting ammonium into urea was more abundant at higher elevations while ureC converting urea into ammonium was less abundant, which was consistent with soil ammonium contents. Significant correlations were observed between N-cycling genes (ureC, gdh and amoA) and nitrous oxide flux, suggesting that they contributed to community metabolism. Lastly, we found by CCA, Mantel tests and the similarity tests that soil pH, temperature, NH4+M-bM-^@M-^SN and vegetation diversity accounted for the majority (81.4%) of microbial community variations, suggesting that these four attributes were major factors affecting soil microbial communities. Based on these observations, we predict that climate changes in the Tibetan grasslands are very likely to change soil microbial community functional structure, with particular impacts on microbial N cycling genes and consequently microbe-mediated soil N dynamics. Twelve samples were collected from four elevations (3200, 3400, 3600 and 3800 m) along a Tibetan grassland; Three replicates in every elevation
Project description:Soils in the alpine grassland store a large amount of nitrogen (N) due to slow decomposition. However, the decomposition could be affected by climate change, which has profound impacts on soil N cycling. We investigated the changes of soil total N and five labile N stocks in the topsoil, the subsoil and the entire soil profile in response to three years of experimental warming and altered precipitation in a Tibetan alpine grassland. We found that warming significantly increased soil nitrate N stock and decreased microbial biomass N (MBN) stock. Increased precipitation reduced nitrate N, dissolved organic N and amino acid N stocks, but increased MBN stock in the topsoil. No change in soil total N was detected under warming and altered precipitation regimes. Redundancy analysis further revealed that soil moisture (26.3%) overrode soil temperature (10.4%) in explaining the variations of soil N stocks across the treatments. Our results suggest that precipitation exerted stronger influence than warming on soil N pools in this mesic and high-elevation grassland ecosystem. This indicates that the projected rise in future precipitation may lead to a significant loss of dissolved soil N pools by stimulating the biogeochemical processes in this alpine grassland.
Project description:Genetic and limited palaeoanthropological data suggest that Denisovans, a sister group to Neanderthals, were once widely distributed in eastern Eurasia, likely stretching from high-latitude Siberia, to the high-altitude Tibetan Plateau, to the low-latitude subtropical regions of southeast Asia. This suggests that Denisovans were capable of adapting to a highly diverse range of environments, but archaeological evidence for this is currently limited. As a result, we know little about their behaviours, including subsistence strategies, across the vast areas they likely occupied. Here, we describe the late Middle to Late Pleistocene faunal assemblage from Baishiya Karst Cave on the Tibetan Plateau, where the Xiahe Denisovan mandible and Denisovan sedimentary mtDNA were found, by integrating proteomic screening into traditional zooarchaeological analysis. The results indicate that the faunal assemblage consists of a diverse range of animals, including megafauna, large mammals, small mammals and birds, but is dominated by medium-sized herbivores. Frequent cut marks and percussion traces on bone surfaces throughout the assemblage, even on carnivore bones, indicate that Denisovan activities in Baishiya Karst Cave from at least 190 to 30 thousand years are responsible for the fauna assemblage accumulation. Thorough utilization of acquired animal resources, even perhaps the fur, too, might have helped Denisovans to survive through the last two glacial-interglacial cycles on the cold high-altitude Tibetan Plateau. Our results shed new light on Denisovan behaviours and their adaptations to the diverse and fluctuated environments in the Middle and Late Pleistocene eastern Eurasia.