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SRP151306
Saccharomyces cerevisiae
50 Downloadable Samples
Illumina HiSeq 2500
Description
Transcriptome of S. cerevisiae in shifts between glucose and maltose media with different re-growth conditions Overall design: Cells are pregrown in maltose, then grown for different durations in glucose and then washed back to maltose
Publication Title
A new protocol for single-cell RNA-seq reveals stochastic gene expression during lag phase in budding yeast.
Sample Metadata Fields
Subject
View Samples- Saccharomyces cerevisiae
- 24 Downloadable Samples
- Illumina HiSeq 2000
Description
The behavior of yeast cells during industrial processes such as the production of beer, wine and bioethanol has been extensively studied. By contrast, our knowledge about yeast physiology during solid state processes, such as bread dough, cheese or cocoa fermentation remains limited. We investigated changes in the transcriptome of three genetically distinct Saccharomyces cerevisiae strains during bread dough fermentation. Our results show that regardless of the genetic background, all three strains exhibit similar changes in expression patterns. At the onset of fermentation, expression of glucose-regulated genes changes dramatically, and the osmotic stress response is activated. The middle fermentation phase is characterized by the induction of genes involved in amino acid metabolism. Finally, at the latest time point, cells suffer from nutrient depletion and activate pathways associated with starvation and stress response. Further analysis shows that genes regulated by the High Osmolarity Glycerol (HOG) pathway, the major pathway involved in the response to osmotic stress and glycerol homeostasis, are among the most differentially expressed genes at the onset of fermentation. More importantly, deletion of HOG1 and other genes of this pathway significantly reduces fermentation capacity. Together, our results demonstrate that cells embedded in a solid matrix such as bread dough suffer severe osmotic stress, and that a proper induction of the HOG pathway is critical for an optimal fermentation.
Publication Title
Dynamics of the Saccharomyces cerevisiae transcriptome during bread dough fermentation.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 18 Downloadable Samples
Affymetrix Yeast Genome 2.0 Array (yeast2)
Description
When grown on solid substrates, different microorganisms often form colonies with very specific morphologies. Whereas the pioneers of microbiology often used colony morphology to discriminate between species and strains, the phenomenon has not received much recent attention. In this study, we use a genome-wide assay in the model yeast Saccharomyces cerevisiae to identify all genes that affect colony morphology. We show that several major signaling cascades, including the MAPK, TORC, SNF1 and RIM101 pathways play a role, indicating that morphological changes are a reaction to changing environments. Other genes that affect colony morphology are involved in protein sorting and epigenetic regulation. Interestingly, the screen reveals only few genes that are likely to play a direct role in establishing colony morphology, one notable exception being FLO11, a gene encoding a cell-surface adhesin that has already been implicated in colony morphology, biofilm formation, and invasive and pseudohyphal growth. Using a series of modified promoters to tune FLO11 expression, we confirm the central role of Flo11 and show that differences in FLO11 expression result in distinct colony morphologies. Together, our results provide a first comprehensive looks at the complex genetic network that underlies the diversity in the morphologies of yeast colonies.
Publication Title
Identification of a complex genetic network underlying Saccharomyces cerevisiae colony morphology.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 4 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
The budding yeast, Saccharomyces cerevisiae, has emerged as an archetype of eukaryotic cell biology. Here we show that S. cerevisiae is also a model for the evolution of cooperative behavior by revisiting flocculation, a self-adherence phenotype lacking in most laboratory strains. Expression of the gene FLO1 in the laboratory strain S288C restores flocculation, an altered physiological state, reminiscent of bacterial biofilms. Flocculation protects the FLO1-expressing cells from multiple stresses, including antimicrobials and ethanol. Furthermore, FLO1+ cells avoid exploitation by non-expressing flo1 cells by self/non-self recognition: FLO1+ cells preferentially stick to one another, regardless of genetic relatedness across the rest of the genome. Flocculation, therefore, is driven by one of a few known green beard genes, which direct cooperation towards other carriers of the same gene. Moreover, FLO1 is highly variable among strains both in expression and in sequence, suggesting that flocculation in S. cerevisiae is a dynamic, rapidly-evolving social trait.
Publication Title
FLO1 is a variable green beard gene that drives biofilm-like cooperation in budding yeast.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 36 Downloadable Samples
- Affymetrix Human Genome U219 Array (hgu219), Affymetrix Human Gene 1.1 ST Array (hugene11st)
Description
Interleukin-6 (IL-6) is an important growth factor for estrogen receptor-alpha (ER) positive breast cancer, and elevated serum IL-6 is associated with poor prognosis. We firstly demonstrated that pSTAT3 is the primary downstream IL-6 signaling pathway in ER-positive breast cancer, using ten different breast cancer cell lines. Three-dimensional cultures of these cell lines were also used to develop a 17-gene IL-6 specific gene signature that could be used to identify IL-6 driven disease. This signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. To further validate this IL-6 signature, we obtained 36 human ER-positive breast cancer tumor samples with matched serum for gene expression profiling and determination of an IL-6 pathway activation score (PAS). Patients with high IL-6 PAS were also enriched for elevated serum IL-6 (>=10 pg/ml). We then utilized a murine MCF-7 xenograft model to determine the role of IL-6 in ER-positive breast cancer and potential anti-IL-6 therapy in vivo. When IL-6 was administered in vivo, MCF-7 cells engrafted without the need for estrogen supplementation. Subsequently, we prophylactically treated mice at MCF-7 engraftment with an anti-IL-6 antibody (siltuximab), fulvestrant or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, when tumors were allowed to grow to 125 mm3 before treatment, siltuximab alone demonstrated tumor regressions in 90% (9/10) of tumors. Given the established role for IL-6 in ER+ breast cancer, this data demonstrates the potential for anti-IL-6 therapeutics.
Publication Title
Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer.
Sample Metadata Fields
Specimen part
View Samples- Escherichia coli
- 12 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
We measured transcriptional changes resulting from overexpression or downregulation of the GTPase Obg.
Publication Title
Obg and Membrane Depolarization Are Part of a Microbial Bet-Hedging Strategy that Leads to Antibiotic Tolerance.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 49 Downloadable Samples
- Illumina HiSeq 2000
Description
We tested how complete or partial loss of endophilin A1, A2 and A3 affects gene expression in mouse hippocampus. Total loss of endophilin (triple knock-outs, TKO) was assessed in newborn mice, since the TKO mice only survive only several hours after birth. Partial loss of endophilin (endoA1,A2 double knock-out, DKO) was assessed between Overall design: 2-3 weeks of age (p13-21).
Publication Title
Endophilin-A Deficiency Induces the Foxo3a-Fbxo32 Network in the Brain and Causes Dysregulation of Autophagy and the Ubiquitin-Proteasome System.
Sample Metadata Fields
Subject
View Samples- Homo sapiens
- 19 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Hypoxia is a low oxygen condition that occurs in the developing tumor mass and that is associated with poor prognosis and resistance to chemo- and radio-therapy. The definition of the hypoxia gene signature is fundamental for the understanding of tumor biology, as in the case of neuroblastoma, the most common pediatric solid tumor. The issue of identifying a significant group of variables in microarray gene expression experiments is particularly difficult due to the typical high dimensional nature of the data and great effort has been spent in the development of feature selection techniques.
Publication Title
A biology-driven approach identifies the hypoxia gene signature as a predictor of the outcome of neuroblastoma patients.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 9 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Neuroblastoma is a pediatric tumor of the peripheral sympathetic nervous system with a highly variable prognosis. Activation of the PI3K/AKT pathway in neuroblastoma is correlated with poor patient prognosis, but the precise downstream effectors mediating this effect have not been determined. Here, we identify the forkhead transcription factor FOXO3a as a key target of the PI3K/AKT pathway in neuroblastoma. FOXO3a expression was elevated in low stage neuroblastoma tumors and normal embryonal neuroblasts, but reduced in late stage neuroblastoma. Inactivation of FOXO3a by AKT was essential for neuroblastoma cell survival. Treatment of neuroblastoma cells with the dual PI3K/mTOR inhibitor PI-103 activated FOXO3a and triggered apoptosis. This effect was rescued by FOXO3a silencing. Conversely, apoptosis induced by PI-103 or the AKT inhibitor MK-2206 was potentiated by FOXO3a overexpression. Further, levels of total or phosphorylated FOXO3a correlated closely with apoptotic sensitivity to MK-2206. In clinical specimens, there was an inverse relationship between gene expression signatures regulated by PI3K signaling and FOXO3a transcriptional activity. Moreover, high PI3K activity and low FOXO3a activity were each associated with an extremely poor prognosis. Our work indicates that expression of FOXO3a and its targets offer useful prognostic markers as well as biomarkers for PI3K/AKT inhibitor efficacy in neuroblastoma.
Publication Title
FOXO3a is a major target of inactivation by PI3K/AKT signaling in aggressive neuroblastoma.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 23 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The transcription factor OTX2 has been implicated as an oncogene in medulloblastoma, which is the most common malignant brain tumor in children. It is highly expressed in most medulloblastomas and amplified in a subset of them. The role of OTX2 in medulloblastoma and its downstream targets are unclear. Therefore, we generated D425 medulloblastoma cells in which we can silence endogenous OTX2 by inducible shRNA. Silencing of OTX2 strongly inhibited cell proliferation and resulted in a neuronal-like differentiation. Expression profiling of time courses after silencing showed a progressive change in gene expression for many cellular processes. Down regulated genes were highly enriched for cell cycle and visual perception genes, while up regulated genes were enriched for genes involved in development and differentiation. This shift in expression profiles is reminiscent to changes described to occur during normal cerebellum development. OTX2 is expressed in proliferating granular progenitor cells, but the expression diminishes when these cells exit the cell cycle and start differentiating. ChIP-on-chip analyses of OTX2 in D425 cells showed that cell cycle and perception genes were direct OTX2 targets, while regulation of most differentiation genes appears to be indirect. These analyses provide the first insight in the molecular network of OTX2, demonstrating that OTX2 is essential in medulloblastoma and directly drives proliferation by regulating the expression of cell cycle genes. Since many of these genes also correlate in expression with OTX2 in primary tumors, they might be potential targets for therapy in medulloblastoma patients.
Publication Title
OTX2 directly activates cell cycle genes and inhibits differentiation in medulloblastoma cells.
Sample Metadata Fields
Cell line, Time
View Samples