Project description:The ability of Microlunatus phosphovorus to accumulate large amounts of polyphosphate (Poly-P) plays an important role in removing soluble phosphorus from wastewater. Our analyses indicate that Microlunatus phosphovorus accumulates Poly-P under aerobic conditions but releases phosphorus under anaerobic conditions. To determine the mechanisms underlying Poly-P metabolism, we compared transcriptional profiles under aerobic and anaerobic conditions. Significant differences were detected in the expression levels of genes associated with Poly-P metabolism between aerobic and anaerobic conditions. These findings enhance our understanding of phosphate metabolism in a major bacterial species involved in wastewater phosphorus reduction.
Project description:Intestinal microbiota dysbiosis is related to many metabolic diseases in human health. Meanwhile, as an irregular environmental light-dark cycle, short-day (SD) may induce host circadian rhythms disturbances and worsen the risks of gut dysbiosis. Herein, we investigated how LD cycles regulate intestinal metabolism upon the destruction of gut microbes with antibiotic treatments. The transcriptome data indicated that SD have some negative effects on hepatic metabolism, endocrine, digestive, and diseases processes compared with normal light-dark cycle (NLD).The SD induced epithelial and hepatic purine metabolism pathway imbalance in ABX mice, the gut microbes, and their metabolites, all of which could contribute to host metabolism and digestion, endocrine system disorders, and may even cause diseases in the host.
Project description:We report the application of bulk RNA-sequencing-based technology for high-throughput profiling to examine the individual and combinatorial effects of the liver circadian clock and gut microbes on the liver transcriptome over 24-hours. Principle Component Analysis demonstrated that functionality of the liver circadian clock is the primary driver of the hepatic transcriptome profile, and presence of microbes is the secondary driver. We identified a range of significantly oscillating transcripts within each experimental group using empirical_JTK_CYCLE, and revealed an overall increase in oscillating transcripts with both the loss of cuntional liver clock and gut microbes. Network analysis via Spearman correlation revealed that a broken liver clock results in increased connections and correlated transcripts only in the presence of gut microbes. Finally, we show by differential expression and gene set enrichment analysis that several key metabolic pathways, particularly carbohydrate and lipid metabolism, were significantly downregulated when the liver clock is broken, regardless of microbial status. This study demonstrates the complex contributions of the liver circadian clock and gut microbes in transcriptome programming, both over time and overall.
Project description:The liver circadian clock is reprogrammed by nutritional challenge through the rewiring of specific transcriptional pathways. As the gut microbiota is tightly connected to host metabolism, whose coordination is governed by the circadian clock, we explored whether gut microbes influence circadian homeostasis and how they distally control the peripheral clock in the liver. Using fecal transplant procedures we reveal that, in response to high fat diet, the gut microbiota drives PPARγ-mediated activation of newly oscillatory transcriptional programs in the liver. Moreover, antibiotics treatment prevents PPARγ-driven transcription in the liver, underscoring the essential role of gut microbes in clock reprogramming and hepatic circadian homeostasis. Thus, a specific molecular signature characterizes the influence of the gut microbiome in the liver, leading to the transcriptional rewiring of hepatic metabolism. We used microarray to quantify the tissue specific expression level of circadian genes in terms of total RNA.
Project description:Chinese fir (Cunninghamia lanceolata) is an excellent fast-growing timber species occurring in southern China and has significant value in the forestry industry. In order to enhance the phosphorus utilization efficiency in Chinese fir, four clones named X6, S3, S39 and FK were used, and low phosphorus (LP) stress experiments were performed to analyze the response of different clones to phosphorus deficiency. According to the results on seedling height, maximum root length, leaf blade aspect ratio, root ratio, malondialdehyde content, acid phosphates activity, proline content, soluble protein level, and chlorophyll a and b levels of the tested clones, compared to the control groups (CK), the phosphorus high efficiency clone X6 was screen out for transcriptome sequencing experiments. De novo RNA-seq was then used to sequence the root transcriptomes of X6 under LP stress and CK, and we then compared the gene expression differences under the two conditions. A total of 3416 SDEGs were obtained by comparing the LP and CK groups, among which 1742 were up-regulated and 1682 were down-regulated. All SDEGs obtained from the LP and CK treated samples were subjected to KEGG annotation and classification. Through classification statistical analysis using WEGO software, 607 SDEGs obtained KEGG pathway annotations, which were related to 206 metabolic pathways. In Chinese fir subjected to LP stress, 53 SDEGs related with phosphorus metabolism, and phosphate uptake and transport were obtained from our transcriptome data. Based on the phosphorus metabolism pathway obtained by KEGG classification, combined with previously report on gene annotation related with phosphorus metabolism, the enzymes encoded by SDEG related with phosphorus metabolism and their expression pattern were mapped onto phosphorus metabolism pathway.
Project description:Within the human gut reside diverse microbes coexisting with the host in a mutually advantageous relationship. We comprehensively identified the modulatory effects of phylogenetically diverse human gut microbes on the murine intestinal transcriptome. Gene-expression profiles were generated from the whole-tissue intestinal RNA of mice colonized with various single microbial strains. The selection of microbe-specific effects, from the transcriptional response, yielded only a small number of transcripts, indicating that symbiotic microbes have only limited effects on the gut transcriptome overall. Moreover, none of these microbe-specific transcripts was uniformly induced by all microbes. Interestingly, these responsive transcripts were induced by some microbes but repressed by others, suggesting different microbes can have diametrically opposed consequences.
Project description:In the early stages (30 days) of phosphorus deficiency stress, Epimedium pubescens leaves cope with short-term phosphorus deficiency by increasing the expression of related genes such as carbon metabolism, flavonoid synthesis and hormone signal transduction pathways, producing sufficient energy, scavenging ROS, and adjusting plant morphology. However, with the extension of stress duration to 90 days, the expression of genes related to phosphorus cycling and phosphorus recovery (PHT1-4, PHO1 homolog3, PAP) was upregulated, and transcriptional changes and post-transcriptional regulation (miRNA regulation and protein modification) were enhanced to resist long-term phosphorus deficiency stress. In addition, bHLH, MYB, NAC, WRKY and other families also play an important role in regulating gene expression and coping with phosphorus deficiency stress, especially MYB60 negatively regulates flavonoid synthesis pathway, which is significantly down-regulated in leaves treated with phosphorus deficiency for 30 days, thereby promoting the accumulation of flavonoid compounds in leaves.
Project description:Choline is a water-soluble nutrient essential for human life. Gut microbial metabolism of choline results in the production of trimethylamine (TMA), which upon absorption by the host is converted in the liver to trimethylamine N-oxide (TMAO). Recent studies revealed that TMAO exacerbates atherosclerosis in mice, and positively correlates with the severity of this disease in human. However, which microbes contribute to TMA production in the human gut; the extent to which host factors, e.g., genotype and diet, affect TMA production and colonization of these microbes; as well as the effects TMA-producing microbes have on bioavailability of dietary choline remain largely unknown. We screened a collection of 78 sequenced human intestinal isolates encompassing the major phyla found in the human gut and identified eight strains capable of producing TMA from choline in vitro. Gnotobiotic mouse studies showed that TMAO accumulates in the serum of animals colonized with TMA-producing species, but not in the serum of animals colonized with intestinal isolates that do not generate TMA from choline in vitro. Remarkably, low levels of colonization of TMA-producing bacteria significantly reduced choline levels available to the host. This effect was more pronounced as the abundance of TMA-producing bacteria increased. Our findings provide a framework for designing strategies aimed at changing the representation or activity of TMA-producing bacteria in the human gut and suggest the TMA producing status of the gut microbiota should be considered when making recommendations about choline intake requirements for humans.
Project description:Coronary artery disease (CAD) is a widespread heart condition caused by atherosclerosis and influences millions of people worldwide. Early detection of CAD is challenging due to the lack of specific biomarkers. The gut microbiota and host-microbiota interactions have been well documented to affect human health. However, investigation that reveals the role of gut microbes in CAD is still limited. This study aims to uncover the synergistic effects of host genes and gut microbes associated with CAD through integrative genomic analyses.