Chlamydomonas reinhardtii
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA255778 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR1521610.fastq.gz | Fastqsanger.gz | |||
| SRR1521620.fastq.gz | Fastqsanger.gz | |||
| SRR1521630.fastq.gz | Fastqsanger.gz | |||
| SRR1521640.fastq.gz | Fastqsanger.gz | |||
| SRR1521650.fastq.gz | Fastqsanger.gz |
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Project description:Alga-derived lipids represent an attractive potential source of biofuels. However, lipid accumulation in algae is a stress response tightly coupled to growth arrest, thereby imposing a major limitation on productivity. To identify master regulators of lipid accumulation and decipher the regulation of lipid biosynthetic pathway, we performed an integrative chromatin signature and transcriptomic analysis in the alga Chlamydomonas reinhardtii. Genome-wide histone modification profiling revealed remarkable differences in functional chromatin states between algae and higher eukaryotes and uncovered regulatory components at the core of lipid accumulation pathways. We identified the transcription factor PSR1 as a pivotal master switch that triggers cytosolic lipid hyper-accumulation an order of magnitude higher than stress regimens have achieved. Dissection of the PSR1 target network corroborates its central role in coordinating multiple stress responses. The comprehensive maps of functional chromatin signatures in a major clade of eukaryotic life and the discovery of a central regulator of algal lipid metabolism will facilitate targeted engineering strategies in microalgae.
2015-07-28 | GSE59629 | GEO
Project description:The metabolites derived from microalgae have been attributed with various nutritional and medicinal properties. Therefore, our study aimed to investigate the potential beneficial effects of Chlamydomonas reinhardtii (red), a type of microalgae, in individuals with type 2 diabetes mellitus (T2DM). Mice were fed on high-fat diet and injected with a low dose of streptozotocin to induce T2DM. The diabetic mice were orally treated with either 1% sodium carboxymethylcellulose or Chlamydomonas reinhardtii (red) at doses of 1, 2, or 3 g/kg BW/day for a duration of 4 weeks. The liver sections were subjected to hematoxylin and eosin staining as well as oil red staining for the detection of pathological changes and lipid deposition, respectively. Inflammatory factors in serum were quantified using ELISA kits, while commercial kits were employed to assess oxidative stress-related indicators. Gene expression in liver was analysed by RNA-seq. The results revealed that Chlamydomonas reinhardtii (red) significantly ameliorated fasting blood glucose levels, body weight, triglyceride, and low density lipoprotein cholesterin, while also enhancing oral glucose tolerance and insulin sensitivity. In pathological analysis, Chlamydomonas reinhardtii (red) significantly improved lipid deposition and hepatic tissue damage. Furthermore, Chlamydomonas reinhardtii (red) could obviously decreased the protein expression of G-6-Pase and PEPCK, and regulated the SOCS2/JAK2/STAT5 signaling pathway. Transcriptomic analysis indicated that a total of 972 significantly differentially expressed genes in diabetic mice treated with Chlamydomonas reinhardtii (red). KEGG analyses revealed that lipid and atherosclerosis, MAPK signaling pathway, B cell receptor signaling pathway, TNF signaling pathway, NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, PI3K-Akt signaling pathway were involved in Chlamydomonas reinhardtii (red) modulated process. Therefore, the continuous consumption of Chlamydomonas reinhardtii (red) may have anti-T2DM effects through the inhibition of gluconeogenesis, thus offering a promising alternative for T2DM patient.
2025-01-31 | GSE287670 | GEO
Project description:Alga-derived lipids represent an attractive potential source of biofuels. However, lipid accumulation in algae is a stress response tightly coupled to growth arrest, thereby imposing a major limitation on productivity. To identify master regulators of lipid accumulation and decipher the regulation of lipid biosynthetic pathway, we performed an integrative chromatin signature and transcriptomic analysis in the alga Chlamydomonas reinhardtii. Genome-wide histone modification profiling revealed remarkable differences in functional chromatin states between algae and higher eukaryotes and uncovered regulatory components at the core of lipid accumulation pathways. We identified the transcription factor PSR1 as a pivotal master switch that triggers cytosolic lipid hyper-accumulation an order of magnitude higher than stress regimens have achieved. Dissection of the PSR1 target network corroborates its central role in coordinating multiple stress responses. The comprehensive maps of functional chromatin signatures in a major clade of eukaryotic life and the discovery of a central regulator of algal lipid metabolism will facilitate targeted engineering strategies in microalgae. 1. Genome-wide H3K4me3 time series profiling (at 0 hr, 10 min, 30 min, 1 hr, 2hr, 6 hr, 8 hr, 24 hr and 48 hr after nitrogen starvation) was performed to determine time point to capture maximal chromatin changes. 2. Genome-wide H3K4me3, H3K27ac, H3K9me3, H3K27me3, H3K36me3 and Pol II profiling were performed at 0 hr, 1 hr after nitrogen starvation and 1 hr after sulfur starvation to determine chromatin signatures. Genome-wide H3K4me2 profiling was performed at 0 hr before starvation. 3. Transcriptome time series profiling (at 0 hr, 10 min, 30 min, 1 hr, 2hr, 6 hr, 8 hr, 24 hr and 48 hr after nitrogen and sulfur starvation separately) for chromatin signature characterization and integrative analysis. 4. Genome-wide PSR1 binding profiling was performed with polyclonal antibody against PSR1 peptide A region and PSR1 peptide B region individually. (At 30 min and 1 hr after nitrogen starvation, and 1 hr, 2 hr and 6 hr after sulfur starvation.) Please note that the following reference genome and gene models used in these experiments are linked below; C.reinhardtii_v5.3_genomic_scaffold_plastids.fasta.gz reference_gene_model.gtf.gz These are based off Phytozome (http://www.phytozome.net/) which does not provide access to earlier version data.
2015-07-28 | E-GEOD-59629 | biostudies-arrayexpress
Project description:Chlamydomonas reinhardtii forms lipid droplets rich in triacylglycerols when nutrient-deprived. To begin studying the mechanisms underlying this process, N-deprivation was used to induce triacylglycerol accumulation and changes in developmental programs such as gametogenesis. Comparative global analysis of transcripts under induced and non-induced conditions was applied as a first approach to study molecular changes that promote or accompany triacylglycerol accumulation in cells encountering a new nutrient environment. Towards this goal, high-throughput sequencing technology was employed to generate large numbers of expressed sequence tags of 8 biologically independent libraries (6 Illumina libraries, 2 454 libraries), four for each condition, N-replete and N-deprived, that allowed a statistically sound comparison of expression levels under the two tested conditions. Inferences on metabolism based on transcriptional analysis can only be indirect but were supported in parts by biochemical experiments. N-deprivation led to a marked redirection of metabolism as the carbon source acetate was no longer converted to cell building blocks by the glyoxylate cycle and gluconeogensis, but funneled directly into fatty acid biosynthesis. Protein biosynthesis and photosynthesis were down-regulated and genes of gametogenesis activated. A notable finding was that the genes encoding photosynthetic accessory PSBS proteins of currently unclear function in C. reinhardtii were strongly expressed following N-deprivation, providing a clue to their physiological role. Lipase-encoding genes were found to be some of the most regulated following N-deprivation, suggesting a remodeling of membranes under these conditions. The data provided here represent a rich source for the exploration of the mechanism of oil accumulation in microalgae. Examining N-replete and N-deprived conditions. Three biological replicates each condition.
2010-09-24 | E-GEOD-24365 | biostudies-arrayexpress
Project description:Photosynthesis, the fundamental process using light energy to convert carbon dioxide to organic matter, is vital for life on Earth. It relies on capturing light through light-harvesting complexes (LHC) in photosystem I (PSI) and PSII and on the conversion of light energy into chemical energy. Composition and organization of PSI and PSII core complexes are well conserved across evolution. PSII is particularly sensitive to photodamage but benefits from a large diversity of photoprotective mechanisms, finely tuned to handle the dynamic and ever-changing light conditions. Light Harvesting Complex protein family members (LHC and LHC-like families) have acquired a dual function during evolution. Members of the LHC antenna complexes of PS capture light energy, whereas others dissipate excess energy that cannot be harnessed for photosynthesis. This process mainly occurs through nonphotochemical quenching (NPQ). In this work, we focus on the Light Harvesting complex-Like 4 (LHL4) protein, a LHC-like protein induced by ultraviolet-B (UV-B) and blue light through UV Resistance locus 8 (UVR8) and phototropin photoreceptor-activated signaling pathways in the model green microalgae Chlamydomonas reinhardtii. We demonstrate that alongside established NPQ effectors, LHL4 plays a key role in photoprotection, preventing singlet oxygen accumulation in PSII and promoting cell survival upon light stress. LHL4 protective function is distinct from that of NPQ-related proteins, as LHL4 specifically and uniquely binds to the transient monomeric form of the core PSII complex, safeguarding its integrity. LHL4 characterization expands our understanding of the interplay between light harvesting and photoprotection mechanisms upon light stress in photosynthetic microalgae.
2025-01-28 | GSE255943 | GEO
Project description:Microalgae technology is a promising alternative feedstock for biodiesel production. Chlamydomonas reinhardtii is a unicellular green alga, one of the most important model organisms, that can produce increased lipid yields under abiotic conditions. In this study we show that treatment with 0.1 M of NaCl rapidly raises the amount of neutral lipids in C. reinhardtii, without impairing cellular growth rate, being, therefore, a favorable condition for biomass and energy production. A nuclear proteomic analysis was conducted on salt stress to better understand the molecular mechanism and the regulatory proteins involved in the adaptation to salt stress and increased lipid yields.
2025-10-14 | PXD034581 | Pride
Project description:The widespread presence of microplastics (MPs) in freshwater systems has raised concerns about their potential ecotoxicity on aquatic organisms. In this study, we evaluated the effects of four MPs with different compositions, namely polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC) and polypropylene (PP), on freshwater microalgae Chlamydomonas reinhardtii. PS and PVC MPs caused greater growth inhibition and stronger oxidative stress response than PP and PE MPs. Proteomics analysis was employed to explore the mechanical understanding of the composition-dependent toxicity of MPs on microalgae. Proteins involved in photosynthesis processes were identified as contributors to the diverse responses of microalgae to differently composed MPs. Photosynthesis activity of algae, including pigment content and photoprotective response, was determined to reflect the distinct effect of the four MPs. The indicated down-regulated expression of photosynthetic proteins by proteomics analysis was further confirmed using western blot, with PVC and PS showing greater impacts on their expression reduction. Our findings not only show the composition-dependent effect of MPs on microalgae but also provide important insights into the molecular mechanism of MPs’ toxicity on natural phytoplankton species.
2024-06-06 | PXD052887 |
Project description:Selenium (Se) deficiency is associated with the occurrence of many diseases. However, excessive Se supplementation, especially with inorganic Se, can result in toxicity. Selenoproteins are the major forms of Se in vivo to exert its biological function. Expression of those selenoproteins, especially with the application of a newly developed system, is thus very important for studying the mechanism of Se in nutrition. The use of Chlamydomonas reinhardtii (C. reinhardtii) as a biological vector to express an heterogeneous protein is still at the initial stages of development. In order to investigate the possibility of using this system to express selenoproteins, human 15-KDa selenoprotein (Sep15), a small but widely distributed selenoprotein in mammals, was chosen for the expression platform test. Apart from the wild-type human Sep15 gene fragment, two Sep15 recombinants were constructed containing Sep15 open reading frame (ORF) and the selenocysteine insertion sequence (SECIS) element from either human Sep15 or C. reinhardtii selenoprotein W1, a highly expressed selenoprotein in this alga. Those Sep15-containing plasmids were transformed into C. reinhardtii CC-849 cells. Results showed that Sep15 fragments were successfully inserted into the nuclear genome and expressed Sep15 protein in the cells. The transgenic and wild-type algae demonstrated similar growth curves in low Se culture medium. To our knowledge, this is the first report on expressing human selenoprotein in green alga.
| S-EPMC3705309 | biostudies-literature
Project description:Linear tetrapyrrole (bilin)-based phytochrome sensors optimize photosynthetic light capture by mediating massive gene reprogramming in land plants, yet surprisingly, many sequenced chlorophyte (green) algae lack phytochrome genes. Previous studies on the heme oxygenase (hmox1) mutant of Chlamydomonas reinhardtii suggest that bilin biosynthesis in plastids is needed for regulation of a limited nuclear gene network implicated in oxygen detoxification during dark to light transitions. The hmox1 mutant is unable to grow photoautotrophically and poorly acclimates to increased illumination even in the presence of acetate. Here we show that these phenotypes reflect the reduced accumulation of PSI reaction centers as well as a loss of PSI and PSII antennae complexes during photoacclimation. Phenotypically, the hmox1 mutant is similar to the chlorophyll biosynthesis mutants, gun4, crd1 and cth1. However, many of the hmox1 phenotypes can be rescued by the application of exogenous biliverdin IXα, the bilin product of HMOX1; this rescue is independent of photosynthesis but strongly dependent upon blue light. RNA-Seq comparisons of hmox1, 4A+ wild type and two genetically complemented lines also reveal that bilins restore regulation of a small network of photosynthesis-associated nuclear genes. These include genes responsible for chlorophyll biosynthesis (CHLI1/2), PSI light-harvesting (LHCA4) and naphthoquinone metabolism (MEN2), all of which show reduced photoinduction in the hmox1 mutant. We propose that a bilin-based, blue light sensory system is responsible for the maintenance of a functional photosynthetic apparatus in light-grown C. reinhardtii. This critical and possibly ancestral role for bilins may be responsible for retention of bilin biosynthesis in all eukaryotic photosynthetic species.
2019-01-24 | GSE77388 | GEO
Project description:Changes in membrane lipid composition during Iron depletion and starvation in Chlamydomonas reinhardtii
| PRJNA190650 | ENA