Project description:Desert microbial communities live in a pulsed ecosystem shaped by isolated and rare precipitation events. The Namib desert is one of the oldest continuously hyperarid ecosystems on Earth. In this study, surface microbial communities of open soils (without sheltering features like rocks, vegetation or biological soil crusts) are analysed. We designed an artificial rainfall experiment where a 7x7 (3.5 x 3.5 m) plot remained dry while an adjacent one received a 30 mm simulated rain. Samples were taken randomly in parallel from both plots at 10 min, 1 h, 3 h, 7 h, 24 h and 7 days after the watering moment. Duplicate libraries were generated from total (rRNA depleted) RNA and sequenced 2x150 bp in an Illumina Hiseq 4000 instrument.
Project description:Global warming substantially changes precipitation patterns in the Tibetan plateau, with projection of increased precipitation in southern and northern Tibet but decreased precipitation in the center. Understanding mechanisms of such changes in greenhouse gas emissions is of vital importance in predicting ecosystem feedbacks to climate changes. Nonetheless, it has been hampered by limited knowledge in soil microbial communities, one of the major drivers of greenhouse gas emission. Here, we report a field experiment simulating drying and wetting conditions in the Tibetan grassland. Our field site is located at the Haibei Alpine Grassland Ecosystem Research Station in the northeast of Tibet Plateau, China, and we employed GeoChip 5.0 180K to analyze microbial responses.
Project description:Global warming substantially changes precipitation patterns in the Tibetan plateau, with projection of increased precipitation in southern and northern Tibet but decreased precipitation in the center. Understanding mechanisms of such changes in greenhouse gas emissions is of vital importance in predicting ecosystem feedbacks to climate changes. Nonetheless, it has been hampered by limited knowledge in soil microbial communities, one of the major drivers of greenhouse gas emission. Here, we report a field experiment simulating drying and wetting conditions in the Tibetan grassland. Our field site is located at the Haibei Alpine Grassland Ecosystem Research Station in the northeast of Tibet Plateau, China, and we employed GeoChip 5.0 180K to analyze microbial responses. 18 samples were collected from 3 plots in Haibei Station, with 6 replicates in each plot
Project description:Gene deserts spanning more than 500kb of non-protein coding genomic sequence are considered evolutionarily ancient and stable and are enriched in the vicinity of developmental regulator genes (Ovcharenko 2005). These extensive genomic regions typically harbor numerous conserved elements with predicted gene regulatory potential pointing to critical tissue-specific functions during development. Nevertheless, the biological necessity and underlying funtional enhancer landscapes of most gene deserts near developmental transcription factors (TFs) remain unknown, and it is unclear how precise pleiotropic expression patterns emerge from gene desert sequence. Here, we investigated the cis-regulatory architecture and function of a gene desert flanking the mouse Shox2 transcriptional regulator which itself is essential for embryonic limb, craniofacial, and cardiac pacemaker development. By combining epigenomic enhancer prediction, transgenic reporter validation and region-specific chromatin capture (C-HiC), we define the embryonic in vivo enhancer landscape and chromatin topology of the Shox2 gene desert. Targeted and context-specific genomic deletions uncover the gene desert not only as a regulator of embryonic survival through enhancer-mediated control of cardiac Shox2 expression, but also link distinct subsets of tissue-specific gene desert enhancers to the regulation of craniofacial patterning and proximal limb development. Our results hence identify the Shox2 gene desert as a fundamental genomic unit indispensable for pleiotropic patterning, robust organ morphogenesis and embryonic development progression by serving as a dynamic hub for tissue-specific developmental enhancers.