Project description:Evaluation of short-read-only, long-read-only, and hybrid assembly approaches on metagenomic samples demonstrating how they affect gene and protein prediction which is relevant for downstream functional analyses. For a human gut microbiome sample, we use complementary metatranscriptomic, and metaproteomic data to evaluate the metagenomic-based protein predictions.
Project description:In this study transcriptomic data of three life history stages of Orciraptor agilis was generated: 1) Gliding cells in absence of food ('gliding'), 2) Cells attached to the cell wall of its algal prey during perforation ('fattacking'), 3) Cells after acquisition of the algal plastid material ('digesting'). Furthermore, RNA-seq of the algal prey Mougeotia sp. was also performed. A de novo transcriptome assembly of the algal reads was performed in order to identify and substract algal reads of the Orciraptor samples by mapping the Orciraptor reads to the algal transcriptome. After this filtering step the remaining Orciraptor reads from all libraries were pooled for a de novo transcriptome assembly of Orciraptor agilis. This transcriptome was the basis for a comparative transcriptomic study in which transcript expression was compared between the three life history stages.
Project description:The gut microbiome is significantly altered in inflammatory bowel diseases, but the basis of these changes is not well understood. We have combined metagenomic and metatranscriptomic profiling of the gut microbiome to assess changes to both bacterial community structure and transcriptional activity in a mouse model of colitis. Gene families involved in microbial resistance to oxidative stress, including Dps/ferritin, Fe-dependent peroxidase and glutathione S-transferase, were transcriptionally up-regulated in colitis, implicating a role for increased oxygen tension in gut microbiota modulation. Transcriptional profiling of the host gut tissue and host RNA in the gut lumen revealed a marked increase in the transcription of genes with an activated macrophage and granulocyte signature, suggesting the involvement of these cell types in influencing microbial gene expression. Down-regulation of host glycosylation genes further supports a role for inflammation-driven changes to the gut niche that may impact the microbiome. We propose that members of the bacterial community react to inflammation-associated increased oxygen tension by inducing genes involved in oxidative stress resistance. Furthermore, correlated transcriptional responses between host glycosylation and bacterial glycan utilisation support a role for altered usage of host-derived carbohydrates in colitis. Complementary transcription profiling data from the mouse hosts have also been deposited at ArrayExpress under accession number E-MTAB-3590 ( http://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-3590/ ).
Project description:<p>Studies have emphasized the importance of disease-associated microorganisms in perturbed communities, however, the protective roles of commensals are largely under recognized and poorly understood. Using acne as a model disease, we investigated the determinants of the overall virulence property of the skin microbiota when disease- and health-associated organisms coexist in the community. By ultra-deep metagenomic shotgun sequencing, we revealed higher relative abundances of propionibacteria and Propionibacterium acnes phage in healthy skin. In acne patients, the microbiome composition at the species level and at P. acnes strain level was more diverse than in healthy individuals, with enriched virulence-associated factors and reduced abundance of metabolic synthesis genes. Based on the abundance profiles of the metagenomic elements, we constructed a quantitative prediction model, which classified the clinical states of the host skin with high accuracy in both our study cohort (85%) and an independent sample set (86%). Our results suggest that the balance between metagenomic elements, not the mere presence of disease-associated strains, shapes the overall virulence property of the skin microbiota. This study provides new insights into the microbial mechanism of acne pathogenesis and suggests probiotic and phage therapies as potential acne treatments to modulate the skin microbiota and to maintain skin health.</p>
Project description:The Lobaria pulmonaria holobiont consists of algal, fungal, cyanobacterial, and integrated diverse bacterial components and thrives in undisturbed, humid forests. We set out to investigate the role of the microbiome of L. pulmonaria in the adaptation of this ecologically sensitive lichen species to diverse climatic conditions. Our central hypothesis posited that microbiome composition and functionality aligns with continental-scale climatic parameters related to temperature and precipitation. In addition, we tested whether short-term weather dynamics, sampling season, and the genotypes of the fungal and algal partners influenced the variation in the lichen microbiome. Insights into compositional and functional changes within the microbiome were obtained using metaproteomics. Comparative examinations between Sub-Atlantic Lowland (SAL) and Alpine (ALP) regions unveiled the distinct impact of climate on microbiome functions.