Project description:The marbled crayfish (Procambarus virginalis) is a unique freshwater crayfish characterized by genetic uniformity, phenotypic variability, and substantial invasive potential. As invasion into different habitats occurs in the absence of genetic variation, epigenetic mechanisms have been suggested to mediate phenotypic adaptation. However, epigenetic regulation has not been analyzed in this organism yet. Here we show that the recently published P. virginalis draft genome sequence encodes a conserved DNA methylation system. Whole-genome bisulfite sequencing of multiple replicates and different tissues revealed a methylation pattern that is characterized by gene body methylation of housekeeping genes. Interestingly, this pattern was largely tissue-invariant, suggesting a function that is unrelated to cell-fate specification. Indeed, integrative analysis of RNA-seq datasets showed that gene body methylation correlated with stable gene expression, while unmethylated genes often showed a high degree of inter-individual expression variation. Our findings thus establish the methylome of an emerging model organism and suggest that methylation-dependent regulation of gene expression variability may facilitate the phenotypic adaptation and invasive spread of this animal.
Project description:Lactobacillus casei is remarkably adaptive to diverse habitats. To understand the evolution and adaptation of Lb. casei strains isolated from different environments, the gene content of 22 Lb. casei strains isolated from various habitats (cheeses, n=8; plant materials, n=8; and human sources, n=6) were examined by comparative genome hybridization with an Lb. casei ATCC 334-based microarray.
2009-03-17 | GSE15030 | GEO
Project description:phyllospheric microorganism in different habitats
Project description:Polynucleobacter asymbioticus strain QLW-P1DMWA-1T represents a group of highly successful heterotrophic planktonic bacteria, dwelling in freshwater systems (lakes, ponds, and streams) across all climatic zones and across all continents. This includes habitats characterised by strongly fluctuating environmental conditions. So the experiments were designed to mimick winter and summer scenarios with additional impact of UV irradiation. Comparative transcriptomic studies were conducted to analyse gene-expression levels in contrasting experimental conditions. Overall, molecular candidates were revealed that may contribute in rapid acclimatisation of this strain in their immediate environment.
Project description:Iron-sulfur minerals such as pyrite are found in many marine benthic habitats. At deep-sea hydrothermal vent sites they occur as massive sulfide chimneys. Hydrothermal chimneys formed by mineral precipitation from reduced vent fluids upon mixing with cold oxygenated sea water. While microorganisms inhabiting actively venting chimneys and utilizing reduced compounds dissolved in the fluids for energy generation are well studied, only little is known about the microorganisms inhabiting inactive sulfide chimneys. We performed a comprehensive meta-proteogenomic analysis combined with radiometric dating to investigate the diversity and function of microbial communities found on inactive sulfide chimneys of different ages from the Manus Basin (SW Pacific). Our study sheds light on potential lifestyles and ecological niches of yet poorly described bacterial clades dominating inactive chimney communities.
Project description:In many habitats, microorganisms are exposed to high or fluctuating salinities and evolved specific acclimation strategies to thrive in those environments. Euryhaline microorganisms can grow in a broad range of salinities, from low ionic strength like freshwater up to twofold seawater salinities. Here, we analyzed the salt acclimation process of the euryhaline model cyanobacterium Synechocystis sp. PCC 6803 in a multi-omics approach by combining transcriptomic, proteomic and metabolomic analyses. The Overall, the comparison of salt-induced proteome and transcriptome changes revealed a good correleation between the proteome and transcriptome that as most the majority of stably up-regulated proteins also showed elevated mRNA transcript levels. However, a dynamic reorganization of the transcriptome occurred during the first hours after salt shock, which probably also involves the action of small regulatory RNAs acting at the post-transcriptional level. In addition to the rapid and stable steady upregulation of compatible solute biochemistry, a dynamic reorganization of the transcriptome occurred during the first hours after salt shock, which probably involves the action of small regulatory RNAs. Moreover, the coordinated induction of several stress proteins known to be involved in iron and oxidative stress responses as well as of mechano-sensitive channels was observed. Based on these data, an extended salt stimulon can be defined comprising many proteins directly or indirectly related to compatible solute metabolism, ion and water movements as well as a defined set of small regulatory RNAs. Moreover, the massive accumulation of the compatible solute glucosylglycerol had large impact on the overall carbon and nitrogen metabolism. Our comprehensive data set provides the basis for future attempts to engineer cyanobacterial salt tolerance and to search for processes regulating this important environmental acclimation process.
Project description:Plants are colonized by a variety of microorganisms, the plant microbiota. In the phyllosphere, the above-ground parts of plants, bacteria are the most abundant inhabitants. Most of these microorganisms are not pathogenic and the plant responses to commensals or to pathogen infection in the presence of commensals are not well understood. We report the Arabidopsis leaf transcriptome after 3 to 4 weeks of colonization by Methylobacterium extorquens PA1 and Sphingomonas melonis Fr1, representatives of two abundant genera in the phyllosphere, compared to axenic plants. In addition, we also sequenced the transcriptome of Arabidopsis 2 and 7 days after spray-infection with a low dose of P. syringae DC3000 and in combination with the commensals.