Freshwater metagenome
Ontology highlight
ABSTRACT:
PROVIDER: PRJDB11759 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Eukaryotic community structures in anaerobic granular sludge based on 18S rRNA gene sequencing
| PRJDB7247 | ENA
Project description:Iron-rich pelagic aggregates (iron snow) were collected directly onto silicate glass filters using an electronic water pump installed below the redoxcline. RNA was extracted and library preparation was done using the NEBNext Ultra II directional RNA library prep kit for Illumina. Data was demultiplied by GATC sequencing company and adaptor was trimmed by Trimgalore. After trimming, data was processed quality control by sickle and mRNA/rRNA sequences were sorted by SortmeRNA. mRNA sequences were blast against NCBI-non redundant protein database and the outputs were meganized in MEGAN to do functional analysis. rRNA sequences were further sorted against bacterial/archeal 16S rRNA, eukaryotic 18S rRNA and 10,000 rRNA sequences of bacterial 16S rRNA, eukaryotic 18S rRNA were subset to do taxonomy analysis.
2021-10-15 | E-MTAB-9686 | biostudies-arrayexpress
Project description:Environmental variation along the geographical space can shape populations by natural selection. In the context of global warming and changing precipitation regimes, it is crucial to understand the role of environmental heterogeneity in tropical trees adaptation, given their disproportional contribution to water and carbon biogeochemical cycles. Here, we investigated how heterogeneity in freshwater availability along tropical wetlands has influenced molecular variations of the black mangrove (Avicennia germinans). A total of 57 trees were sampled at seven sites differing markedly in precipitation regime and riverine freshwater inputs. Using 2,297 genome‐wide single nucleotide polymorphic markers, we found signatures of natural selection by the association between variations in allele frequencies and environmental variables, including the precipitation of the warmest quarter and the annual precipitation. Additionally, we found candidate loci for selection based on statistical deviations from neutral expectations of interpopulation differentiation. Most candidate loci within transcribed sequences were functionally associated with central aspects of drought tolerance or plant response to drought. Moreover, our results suggest the occurrence of the rapid evolution of a population, probably in response to sudden and persistent limitations in plant access to soil water, following a road construction in 1974. Observations supporting rapid evolution included the reduction in tree size and changes in allele frequencies and in transcript expression associated with increased drought tolerance through the accumulation of osmoprotectants and antioxidants, biosynthesis of cuticles, protection against protein degradation, stomatal closure, photorespiration and photosynthesis. We describe a major role of spatial heterogeneity in freshwater availability in the specialization of this typically tropical tree.
2020-05-15 | GSE123659 | GEO
Project description:Eutrophication can lead to an uncontrollable increase in algal biomass, which has repercussions for the entire microbial and pelagic community. Studies have shown how nutrient enrichment affects microbial species succession, however details regarding the impact on community functionality are rare. Here, we applied a metaproteomic approach to investigate the functional changes to algal and bacterial communities, over time, in oligotrophic and eutrophic conditions, in freshwater microcosms. Samples were taken early during algal and cyanobacterial dominance and later under bacterial dominance. 1048 proteins, from the two treatments and two timepoints, were identified and quantified by their exponentially modified protein abundance index. In oligotrophic conditions, Bacteroidetes express extracellular hydrolases and Ton-B dependent receptors to degrade and transport high molecular weight compounds captured while attached to the phycosphere. Alpha- and Beta-proteobacteria were found to capture different substrates from algal exudate (carbohydrates and amino acids, respectively) suggesting resource partitioning to avoid direct competition. In eutrophic conditions, environmental adaptation proteins from cyanobacteria suggested better resilience compared to algae in a low carbon nutrient enriched environment. This study provides insight into differences in functional microbial processes between oligo- and eutrophic conditions at different timepoints and highlights how primary producers control bacterial resources in freshwater environments.
2016-08-01 | PXD004592 | Pride
Project description:Three-spined stickleback (Gasterosteus aculeatus) represents a convenient model to study microevolution - adaptation to freshwater environment. While genetic adaptations to freshwater are well-studied, epigenetic adaptations attracted little attention. In this work, we investigated the role of DNA methylation in the adaptation of marine stickleback population to freshwater conditions. DNA methylation profiling was performed in marine and freshwater populations of sticklebacks, as well as in marine sticklebacks placed into freshwater environment and freshwater sticklebacks placed into seawater. For the first time, we demonstrated that genes encoding ion channels kcnd3, cacna1fb, gja3 are differentially methylated between marine and freshwater populations. We also showed that after placing marine stickleback into fresh water, its DNA methylation profile partially converges to the one of a freshwater stickleback. This suggests that immediate epigenetic response to freshwater conditions can be maintained in freshwater population. Interestingly, we observed enhanced epigenetic plasticity in freshwater sticklebacks that may serve as a compensatory regulatory mechanism for the lack of genetic variation in the freshwater population. Some of the regions that were reported previously to be under selection in freshwater populations also show differential methylation. Thus, epigenetic changes might represent a parallel mechanism of adaptation along with genetic selection in freshwater environment. This is the RNA-seq experiment, DNA methylation data (bisulfite-seq) is provided under accession number GSE82310.
2021-11-03 | GSE186925 | GEO
Project description:In eukaryotes, biogenesis of ribosomes requires folding and assembly of the precursor rRNA (pre-rRNA) with a large number of proteins and snoRNPs into huge RNA-protein complexes. In spite of intense genetic, biochemical and high resolution cryo-EM studies in Saccharomyces cerevisiae, information about the conformation of the earliest 35S pre-rRNA is limited. To overcome this, we performed high-throughput SHAPE chemical probing on the 35S pre-rRNA associated with 90S pre-ribosomes. We focused our analyses on external (5´ETS) and internal (ITS1) transcribed spacers as well as the 18S region. We show that in the 35S pre-rRNA, the central region of the 18S is in a more open configuration compared to 20S pre-rRNA and that the central pseudoknot is not formed. The essential ribosome biogenesis protein Mrd1 influences the structure of the 18S part locally and is involved in organizing the central pseudoknot and surrounding structures. Our results demonstrate that the U3 snoRNA dynamically interacts with the 35S pre-rRNA and that Mrd1 is required for disrupting U3 snoRNA base-pairing interactions in the 5'ETS. We propose that the dynamic U3 snoRNA interactions and Mrd1 are essential for establishing the structure of the central region of 18S that is required for processing and 40S subunit function.
2018-01-15 | GSE106868 | GEO
Project description:freshwater metagenome Targeted loci environmental
| PRJNA517944 | ENA