Synechococcus / Cyanobium
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ABSTRACT:
PROVIDER: PRJNA718564 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The salinity gradient separating marine and freshwater environments is a major ecological divide, and the mechanisms by which most organisms adapt to new salinity environments are poorly understood. Diatoms are a lineage of ancestrally marine microalgae that have repeatedly colonized and diversified in freshwaters. Cyclotella cryptica is a euryhaline diatom that naturally tolerates a broad range of salinities, thus providing a powerful system for understanding the genomic mechanisms for mitigating and acclimating to low salinity. To understand how diatoms mitigate acute hypoosmotic stress, we abruptly shifted C. cryptica from seawater to freshwater and performed transcriptional profiling at 8 time points across 10 hours. We found substantial remodeling of the transcriptome, with over half of the genome differentially expressed in at least one time point. The peak response occurred within 1 hour, with strong repression of genes involved in functions related to cell growth and osmolyte production, and strong induction of genes implicated in stress defense such as scavenging reactive oxygen species and maintaining osmotic balance. Notably, transcripts largely returned to baseline levels within 4–10 hours, with growth resuming shortly thereafter, suggesting that gene expression dynamics may be useful for predicting acclimation. Moreover, comparison to a study of expression profiling following months-long acclimation of C. cryptica to freshwater revealed little overlap between the genes and processes differentially expressed in cells exposed to acute stress versus fully acclimated conditions. Altogether, this study highlights the power of time-resolved transcriptomics to reveal fundamental insights into how cells dynamically respond to an acute environmental shift and provides new insights into how diatoms mitigate natural salinity fluctuations and have successfully diversified across freshwater habitats worldwide.
2022-06-23 | GSE206725 | GEO
Project description:Picocyanobacteria from the genus Synechococcus are ubiquitous in ocean waters. Their phylogenetic and genomic diversity suggests ecological niche differentiation, but the selective forces influencing this are not well defined. Marine picocyanobacteria are sensitive to Cu toxicity, so adaptations to this stress could represent a selective force within, and between, “species” also known as clades. We compared Cu stress responses in cultures and natural populations of marine Synechococcus from two co-occurring major mesotrophic clades (I and IV). Using custom microarrays and proteomics to characterize expression responses to Cu in the lab and field, we found evidence for a general stress regulon in marine Synechococcus. However, the two clades also exhibited distinct responses to copper. The Clade I representative induced expression of genomic island genes in cultures and Southern California Bight populations, while the Clade IV representative downregulated Fe-limitation proteins. Copper incubation experiments suggest that Clade IV populations may harbor stress-tolerant subgroups, and thus fitness tradeoffs may govern Cu-tolerant strain distributions. This work demonstrates that Synechococcus has distinct adaptive strategies to deal with Cu toxicity at both the clade and subclade level, implying that metal toxicity and stress response adaptations represent an important selective force for influencing diversity within marine Synechococcus populations.
2016-10-28 | GSE89262 | GEO
Project description:In an abundant aquatic groups of microorganisms, SAR11, the transition between salt- and freshwater environments has happened only once: all freshwater SAR11 belong to subclade IIIb/LD12, which has also been found to inhabit coastal environments where salinity varies widely. The first reported isolates of the SAR11 freshwater clade LD12 and a member of the sister clade IIIa from the same region are now available. This project quantifed concentrations of select, known intracellular metabolites within two strains of SAR11: LSUCC0261 and LSUCC0530.
2023-05-09 | MTBLS6991 | MetaboLights
Project description:In this study, RNA-Seq was used to reveal the differences of molecular pathways in hepatopancreas of O. niloticus adapated to water with salinity of 8 or 16 practical salinity (psu), respectively, with fish at freshwater as the control,. Significantly changed pathways were mainly related to lipid metabolism, glucose utilization, protein consumption, osmotic regulation, signal transduction and immunology. Based on the tendencies from freshwater to 8 or 16 psu, the differentially expressed gene unions were categorized into eight unique models, which were further classified into three categories which were constant-change (either keep increasing or decreasing), change-then-stable and stable-then-change. In constant-change category, steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were extremely significantly affected by ambient salinity (P < 0.01), indicating that these pathways play pivotal roles in molecular response to salinity acclimation from freshwater to saline water in O. niloticus, and should be the main research focus in the future. In change-then-stable category, ribosome, oxidative phosphorylation, peroxisome proliferator-activated receptors (PPAR) signaling pathway, fat digestion and absorption changed significantly with ambient increasing salinity (P < 0.01), showing these pathways were sensitive to environmental salinity variation, but had a response threshold, and would stop changing once salinity exceeds the threshold. In stable-then-change category, protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis - keratan sulfate were the top changed pathways (P < 0.01), suggesting that these pathways were not sensitive to salinity variation, but these pathways will respond significantly under salinity exceeding a certain level. The pathways and genes reported in this study laid on a solid foundation for future studies in understanding the underlying mechanism for salinity adaptation of freshwater fish. Examination of 3 different salinities treated hepatopancreas in Nile tilapia
2015-10-31 | E-GEOD-67671 | biostudies-arrayexpress
Project description:In this study, RNA-Seq was used to reveal the differences of molecular pathways in hepatopancreas of O. niloticus adapated to water with salinity of 8 or 16 practical salinity (psu), respectively, with fish at freshwater as the control,. Significantly changed pathways were mainly related to lipid metabolism, glucose utilization, protein consumption, osmotic regulation, signal transduction and immunology. Based on the tendencies from freshwater to 8 or 16 psu, the differentially expressed gene unions were categorized into eight unique models, which were further classified into three categories which were constant-change (either keep increasing or decreasing), change-then-stable and stable-then-change. In constant-change category, steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were extremely significantly affected by ambient salinity (P < 0.01), indicating that these pathways play pivotal roles in molecular response to salinity acclimation from freshwater to saline water in O. niloticus, and should be the main research focus in the future. In change-then-stable category, ribosome, oxidative phosphorylation, peroxisome proliferator-activated receptors (PPAR) signaling pathway, fat digestion and absorption changed significantly with ambient increasing salinity (P < 0.01), showing these pathways were sensitive to environmental salinity variation, but had a response threshold, and would stop changing once salinity exceeds the threshold. In stable-then-change category, protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis - keratan sulfate were the top changed pathways (P < 0.01), suggesting that these pathways were not sensitive to salinity variation, but these pathways will respond significantly under salinity exceeding a certain level. The pathways and genes reported in this study laid on a solid foundation for future studies in understanding the underlying mechanism for salinity adaptation of freshwater fish.
2015-10-31 | GSE67671 | GEO
Project description:Colors in the dark: Ancestral trade-offs in picocyanobacteria from the Early Ocean analogue
| PRJNA966923 | ENA