Project description:Aeolian soil erosion, exacerbated by anthropogenic perturbations, has become one of the most alarming processes of land degradation and desertification. By contrast, dust deposition might confer a potential fertilization effect. To examine how they affect topsoil microbial community, we conducted a study GeoChip techniques in a semiarid grassland of Inner Mongolia, China. We found that microbial communities were significantly (P<0.039) altered and most of microbial functional genes associated with carbon, nitrogen, phosphorus and potassium cycling were decreased or remained unaltered in relative abundance by both erosion and deposition, which might be attributed to acceleration of organic matter mineralization by the breakdown of aggregates during dust transport and deposition. As a result, there were strong correlations between microbial carbon and nitrogen cycling genes. amyA genes encoding alpha-amylases were significantly (P=0.01) increased by soil deposition, reflecting changes of carbon profiles. Consistently, plant abundance, total nitrogen and total organic carbon were correlated with functional gene composition, revealing the importance of environmental nutrients to soil microbial function potentials. Collectively, our results identified microbial indicator species and functional genes of aeolian soil transfer, and demonstrated that functional genes had higher susceptibility to environmental nutrients than taxonomy. Given the ecological importance of aeolian soil transfer, knowledge gained here are crucial for assessing microbe-mediated nutrient cyclings and human health hazard. The experimental sites comprised of three treatments of control, soil erosion and deposition, with 5 replicates of each treatment.
Project description:Aeolian soil erosion, exacerbated by anthropogenic perturbations, has become one of the most alarming processes of land degradation and desertification. By contrast, dust deposition might confer a potential fertilization effect. To examine how they affect topsoil microbial community, we conducted a study GeoChip techniques in a semiarid grassland of Inner Mongolia, China. We found that microbial communities were significantly (P<0.039) altered and most of microbial functional genes associated with carbon, nitrogen, phosphorus and potassium cycling were decreased or remained unaltered in relative abundance by both erosion and deposition, which might be attributed to acceleration of organic matter mineralization by the breakdown of aggregates during dust transport and deposition. As a result, there were strong correlations between microbial carbon and nitrogen cycling genes. amyA genes encoding alpha-amylases were significantly (P=0.01) increased by soil deposition, reflecting changes of carbon profiles. Consistently, plant abundance, total nitrogen and total organic carbon were correlated with functional gene composition, revealing the importance of environmental nutrients to soil microbial function potentials. Collectively, our results identified microbial indicator species and functional genes of aeolian soil transfer, and demonstrated that functional genes had higher susceptibility to environmental nutrients than taxonomy. Given the ecological importance of aeolian soil transfer, knowledge gained here are crucial for assessing microbe-mediated nutrient cyclings and human health hazard.
2015-03-28 | GSE67347 | GEO
Project description:soil erosion and fungi
| PRJNA637997 | ENA
Project description:soil erosion effect fungi community
Project description:PRDM9, a histone methyltransferase, initiates meiotic recombination by binding DNA at recombination hotspots and directing the position of DNA double-strand breaks (DSB). The DSB repair mechanism suggests that hotspots should eventually self-destruct, yet genome-wide recombination levels remain constant, a conundrum known as the hotspot paradox. To test if PRDM9 drives this evolutionary erosion, we compared activity of the Prdm9Cst allele in two Mus musculus subspecies, M.m. castaneus, in which Prdm9Cst arose, and M.m. domesticus, into which Prdm9Cst was introduced. Comparing these two strains, we find that haplotype differences at hotspots leads to qualitative and quantitative changes in PRDM9 binding and activity. Most variants affecting PRDM9Cst binding arose and were fixed in M.m castaneus, suppressing hotspot activity. Furthermore, M.m castaneus x M.m domesticus F1 hybrids exhibit novel hotspots, representing sites of historic evolutionary erosion. Together these data support a model where haplotype-specific PRDM9 binding directs biased gene conversion at hotspots, ultimately leading to hotspot erosion. Identify position of meiotic H3K4me3 from various sub-species of mice and F1 hybrids from crosses between subspecies. In addition, perform ChIP-seq analysis on the meiosis-specific methyltransferase PRDM9.
Project description:Cover cropping is an effective method to protect agricultural soils from erosion, promote nutrient and moisture retention, encourage beneficial microbial activity, and maintain soil structure. Reusing winter cover crop root channels with the maize roots during the summer allows the cash crop to extract resources from farther niches in the soil horizon. In this study, we investigate how reusing winter cover crop root channels to grow maize (Zea mays L.) affects the composition and function of the bacterial communities in the rhizosphere using 16S rRNA gene amplicon sequencing and metaproteomics. We discovered that the bacterial community significantly differed among cover crop variations, soil profile depths, and maize growth stages. Re-usage of the root channels increased bacterial abundance, and it further increases as we elevate the complexity from monocultures to mixtures. Upon mixing legumes with brassicas and grasses, the overall expression of several steps of the carbon cycle (C) and the nitrogen cycle (N) improved. The deeper root channels of legumes and brassicas compared to grasses correlated with higher bacterial 16S rRNA gene copy numbers and community roles in the respective variations in the subsoil regimes due to the increased availability of root exudates secreted by maize roots. In conclusion, root channel re-use (monocultures and mixtures) improved the expression of metabolic pathways of the important C and N cycles, and the bacterial communities, which is beneficial to the soil rhizosphere as well as to the growing crops.
Project description:To compare the salivary proteins from healthy and dental erosion patients to determine if there is an absence of proteins forming the enamel pellicle that may reduce their protection from acid erosion
Project description:Female human induced pluripotent stem cells frequently undergo X-chromosome inactivation (XCI) erosion, marked by XIST RNA loss and partial reactivation of the inactive X (Xi). This overlooked phenomenon limits our understanding of its impact on stem cell applications. Here, we show that XCI erosion is frequent and heterogeneous, leading to the reactivation of several X-linked genes. These are primarily located on the short arm of the X chromosome, particularly near escape genes and within H3K27me3-enriched domains, with reactivation linked to reduced promoter DNA methylation. Interestingly, escape genes further increase their expression from Xi upon XCI erosion, highlighting the critical role of XIST in their dosage regulation. Importantly, global (hydroxy)methylation levels and imprinted regions remain unaffected, and analysis of trilineage commitment and cardiomyocyte formation reveals that XCI erosion persists across differentiation. These findings underscore the need for greater awareness of the implications of XCI erosion for stem cell research and clinical applications.
Project description:During culture, female human pluripotent stem cells (hPSCs), including human induced PSCs (hiPSCs) exhibit a propensity for erosion of X-chromosome inactivation (XCI). This phenomenon is characterized by loss of XIST RNA expression and reactivation of a subset of X-linked genes from the inactive X chromosome (Xi). XCI erosion, despite its common occurrence, is often overlooked by the stem cell community, hindering a complete understanding of its impact on both fundamental and translational applications of hiPSCs. Investigating erosion dynamics in female hiPSCs, our study reveals that XCI erosion is a frequent yet heterogeneous phenomenon, resulting in reactivation of several X-linked genes. The likelihood of a gene to erode increases for those located on the short arm of the X chromosome and within H3K27me3-enriched domains. Paradoxically, genes that typically escape XCI are hypersensitive to loss of XIST RNA and XCI erosion. This implies that XIST RNA normally restrain expression levels of these genes on the Xi. Importantly, increased X-linked gene expression upon erosion does not globally impact (hydroxy)methylation levels in hiPSCs or at imprinted regions. By exploring diverse differentiation paradigms, such as trilineage commitment and cardiac differentiation, our study reveals the persistence of abnormal XCI patterns throughout differentiation. This finding has significant implications for fundamental research, translational applications, and clinical use of stem cells. We underscore the importance of raising awareness within the stem cell community regarding XCI erosion and advocate for its inclusion in comprehensive hiPSC quality control.