Relationship between cell cycle and diel transcriptomic changes in metabolism in a unicellular red alga
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PROVIDER: PRJNA545900 | ENA |
REPOSITORIES: ENA
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Project description:Metabolism, cell cycle stages, and related transcriptomes in eukaryotic algae change with the diel cycle of light availability. In the unicellular red alga Cyanidioschyzon merolae, the S and M phases occur at night. To examine how diel transcriptomic changes in metabolic pathways are related to the cell cycle and to identify all genes, for which mRNA levels change depending on the cell cycle, we examined diel transcriptomic changes in C. merolae. In addition, we compared transcriptomic changes between the wild type and transgenic lines, in which the cell cycle was uncoupled from the diel cycle by the depletion of either cyclin-dependent kinase A (CDKA) or retinoblastoma-related (RBR) protein. Of 4,775 nucleus-encoded genes, the mRNA levels of 1,979 genes exhibited diel transcriptomic changes in the wild type. Of these, the periodic expression patterns of 454 genes were abolished in the transgenic lines, suggesting that the expression of these genes is dependent on cell cycle progression. The periodic expression patterns of most metabolic genes, except those involved in starch degradation and de novo dNTP synthesis, were not affected in the transgenic lines, indicating that the cell cycle and transcriptomic changes in most metabolic pathways are independent of the diel cycle. Approximately 40% of the cell–cycle–dependent genes were of unknown function, and approximately 19% of these genes of unknown function are shared with the green alga Chlamydomonas reinhardtii. The dataset presented in this study will facilitate further studies on the cell cycle and its relationship with metabolism in eukaryotic algae.
2019-11-26 | GSE131944 | GEO
Project description:Investigation of whole genome gene expression level changes in two strains of the cyanobacteria Atelocyanobacterium thalasaa (UCYN-A) from environmental samples. The diel gene expression analyzed in this study is further described in Muñoz-Marin, M., I. N. Shilova, T. Shi, H. Farnelid & J. P. Zehr. 2017. Unicellular cyanobacterial symbiosis facilitates aerobic nitrogen fixation. Science (to be submitted).
2018-12-05 | GSE100124 | GEO
Project description:Investigation of whole genome gene expression level changes in Trichodesmium erythraeum IMS101 during a 24-hr light and dark cycle. The diel gene expression analyzed in this study is further described in Muñoz-Marin, M., I. N. Shilova, T. Shi, H. Farnelid & J. P. Zehr. 2019. The transcriptional cycle is suited to daytime N2 fixation in the unicellular cyanobacterium “Candidatus Atelocyanobacterium thalassa” (UCYN-A). mBio 10:e02495-18. https://doi.org/10.1128/mBio.02495-18.
2017-06-11 | GSE99896 | GEO
Project description:Iron (Fe) is an important growth limiting factor for diatoms and its availability is further restricted by changes in the carbonate chemistry of the water. We investigated the physiological attributes and transcriptional profiles of the diatom Thalassiosira pseudonana grown on a day:night cycle under different CO2/pH and iron concentrations, that in combination generated available iron (Fe’) concentrations of 1160, 233, 58 and 12 pM. We found the light-dark conditions to be the main driver of transcriptional patterns, followed by Fe’ concentration and CO2 availability, respectively. At the highest Fe’ (1160 pM), 55% of the transcribed genes were differentially expressed between day and night, whereas at the lowest Fe’ (12 pM), only 28% of the transcribed genes displayed comparable patterns. While Fe limitation disrupts the diel transcriptional patterns for genes in most central metabolism pathways, the diel periodicity of light- signaling molecules and glycolytic genes, was relatively robust in response to reduced Fe’. Moreover, we identified a non-canonical splicing of transcripts encoding triose-phosphate isomerase, a key-enzyme of glycolysis, generating transcript isoforms that would encode proteins with and without an active site. Transcripts that encoded an active enzyme maintained a diel pattern at low Fe’, while transcripts that encoded the non-active enzyme lost the diel pattern. This work illustrates the interplay between nutrient limitation and transcriptional regulation over the diel cycle. Considering that future ocean conditions will reduce the availability of Fe in many parts of the oceans, our work identifies some of the regulatory mechanisms that may shape future ecological communities.
2019-09-12 | GSE131042 | GEO
Project description:Here, we report a transcriptomics analysis on a day in the life of Chlamydomonas reinhardtii. Cultures of this unicellular alga were grown in photobioreactors on a 12 h light / 12 h dark cycle. Samples were collected at regular intervals and subjected to a transcriptomics analysis by RNA-Seq.
2019-01-03 | GSE112394 | GEO
Project description:The unicellular, free-living, nonphotosynthetic chlorophycean alga Polytomella parva, closely related to Chlamydomonas reinhardtii and Volvox carteri, contains colorless, starch-storing plastids. The P. parva plastids lack all light-dependent processes but maintain crucial metabolic pathways. The colorless alga also lacks a plastid genome, meaning no transcription or translation should occur inside the organelle. Here, using an algal fraction enriched in plastids as well as publicly available transcriptome data, we provide a proteomic characterization of the P. parva plastid, ultimately identifying several plastid proteins, both by mass spectrometry and bioinformatic analyses. Altogether these results led us to propose a plastid proteome for P. parva, i.e., a set of proteins that participate in carbohydrate metabolism; in the synthesis and degradation of starch, amino acids and lipids; in the biosynthesis of terpenoids and tetrapyrroles; in solute transport and protein translocation; and in redox homeostasis. This is the first detailed plastid proteome from a unicellular, free-living colorless alga.
2020-12-10 | PXD022051 | Pride
Project description:In many eukaryotes, cytokinesis proceeds in two successive steps: first, ingression of the cleavage furrow and second, abscission of the intercellular bridge. In animal cells, the actomyosin contractile ring is involved in the first step, while the endosomal sorting complex required for transport (ESCRT), which participates in various membrane fusion/fission events, mediates the second step. Intriguingly, in archaea, ESCRT is involved in cytokinesis, raising the hypothesis that the function of ESCRT in eukaryotic cytokinesis descended from the archaeal ancestor. In eukaryotes other than in animals, the roles of ESCRT in cytokinesis are poorly understood. To explore the primordial core mechanisms for eukaryotic cytokinesis, we investigated ESCRT functions in the unicellular red alga Cyanidioschyzon merolae that diverged early in eukaryotic evolution. C. merolae provides an excellent experimental system. The cell has a simple organelle composition. The genome (16.5 Mb, 5335 genes) has been completely sequenced, transformation methods are established, and the cell cycle is synchronized by a light and dark cycle. Similar to animal and fungal cells, C. merolae cells divide by furrowing at the division site followed by abscission of the intercellular bridge. However, they lack an actomyosin contractile ring. The proteins that comprise ESCRT-I-IV, the four subcomplexes of ESCRT, are partially conserved in C. merolae. Immunofluorescence of native or tagged proteins localized the homologs of the five ESCRT-III components [charged multivesicular body protein (CHMP) 1, 2, and 4-6], apoptosis-linked gene-2-interacting protein X (ALIX), the ESCRT-III adapter, and the main ESCRT-IV player vacuolar protein sorting (VPS) 4, to the intercellular bridge. In addition, ALIX was enriched around the cleavage furrow early in cytokinesis. When the ESCRT function was perturbed by expressing dominant-negative VPS4, cells with an elongated intercellular bridge accumulated-a phenotype resulting from abscission failure. Our results show that ESCRT mediates cytokinetic abscission in C. merolae. The fact that ESCRT plays a role in cytokinesis in archaea, animals, and early diverged alga C. merolae supports the hypothesis that the function of ESCRT in cytokinesis descended from archaea to a common ancestor of eukaryotes.
| S-EPMC7169423 | biostudies-literature
Project description:Nannochloropsis oceanica CCMP1779 is a marine unicellular stramenopile and an emerging reference species for basic research on oleogenic microalgae with biotechnological relevance. We investigated its physiology and transcriptome under light/dark cycles. We observed oscillations in lipid content and a predominance of cell division in the first half of the dark phase. Globally, more than 60% of the genes cycled in N. oceanica CCMP1779, with gene expression peaking at different times of the day. Interestingly, the phase of expression of genes involved in certain biological processes was conserved across photosynthetic lineages. Furthermore, in agreement with our physiological studies we found the processes of lipid metabolism and cell division enriched in cycling genes. For example, there was tight coordination of genes involved in the lower part of glycolysis, fatty acid synthesis and lipid production at dawn preceding lipid accumulation during the day. Our results suggest that diel lipid storage plays a key role for N. oceanica CCMP1779 growth under natural conditions making this alga a promising model to gain a basic mechanistic understanding of triacylglycerol production in photosynthetic cells. Our data will help the formulation of new hypotheses on the regulation transcriptional control of cell growth and metabolism in Nannochloropsis. Nannochloropsis oceanica CCMP was entrained to 12:12 light:dark cycles and biological replicates collected every 3 hours for a cycle for a total of 16 samples.
2015-08-01 | E-GEOD-69460 | biostudies-arrayexpress
Project description:Comparative genomic analysis of a photosymbiont evolution
| PRJNA832740 | ENA