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.
FLO1 is a variable green beard gene that drives biofilm-like cooperation in budding yeast.
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View SamplesRNA-Seq is an effective method to study the transcriptome, but can be difficult to apply to scarce or degraded RNA from fixed clinical samples, rare cell populations, or cadavers. Recent studies have proposed several methods for RNA-Seq of low quality and/or low quantity samples, but their relative merits have not been systematically analyzed. Here, we compare five such methods using a comprehensive set of metrics, relevant to applications such as transcriptome annotation, transcript discovery, and gene expression. Using a single human RNA sample, we constructed and deeply sequenced 10 libraries with these methods and two control libraries. We find that the RNase H method performed best for low quality RNA, and can even effectively replace oligo (dT) based methods for standard RNA-Seq. SMART and NuGEN had distinct strengths for low quantity RNA. Our analysis allows biologists to select the most suitable methods and provides a benchmark for future method development. Overall design: Examination of 9 different RNA-Seq libraries starting from total RNA from 5 distinct methods; also 3 control RNA-Seq libraries
Comparative analysis of RNA sequencing methods for degraded or low-input samples.
Specimen part, Cell line, Subject
View SamplesWe have developed a new transgenic mouse strain, expressing a CyclinB1-GFP fusion reporter, which marks replicating cells in the S/G2/M phases of the cell cycle to isolate live replicating and quiescent cells from the liver.
A transgenic mouse marking live replicating cells reveals in vivo transcriptional program of proliferation.
Age, Specimen part
View SamplesThree different cell populations (6 healthy B-lymphocytes, 6 leukemic CLL B-lymphocyte of indolent form and 5 leukemic CLL B-lymphocyte of aggressive form) were stimulated in vitro with an anti-IgM antibody, activating the B-cell receptor (BCR). We analyzed the gene expression at 4 time points (60, 90, 210 and 390 minutes). Each gene expression measurement is performed both in stimulated cells and in control unstimulated cells.
Reverse-engineering the genetic circuitry of a cancer cell with predicted intervention in chronic lymphocytic leukemia.
Specimen part
View SamplesAmyotrophic lateral sclerosis (ALS) is a paralytic degenerative disease of the nervous system. In the SOD1 mouse model of ALS we found loss of the molecular and functional microglia signature associated with pronounced expression of miR-155 in SOD1 mice. We also found increased expression of miR-155 in the spinal cord of ALS subjects. Genetic ablation of miR-155 increased survival in SOD1 mice and reversed the abnormal microglial and monocyte molecular signature. In addition, dysregulated proteins in the spinal cord of SOD1 mice that we identified in human ALS spinal cords and CSF were restored in SOD1G93A/miR155-/- mice. Treatment of SOD1 mice with anti-miR-155 SOD1 mice injected systemically or into the cerebrospinal fluid prolonged survival and restored the microglial unique genetic and microRNA profiles. Our findings provide a new avenue for immune based therapy of ALS by targeting miR-155. Overall design: Total RNA was isolated from whole lumbar spinal cord homogenate from healthy control donors without known neurologic diseases and sporadic and familial ALS.
Targeting miR-155 restores abnormal microglia and attenuates disease in SOD1 mice.
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View SamplesWnt pathway is dysregulated in CLL-We characterized Wnt pathway gene expression in normal B and CLL-B cells and identified Wnt targets in normal B and CLL-B cells through this data set.
Somatic mutation as a mechanism of Wnt/β-catenin pathway activation in CLL.
Specimen part
View SamplesNeuroprotective therapies for retinal degeneration may be used to rescue retinal cells and preserve vision. Hypoxic preconditioning stabilizes the transcription factor HIF-1 in the retina and strongly protects photoreceptors in an animal model of light-induced retinal degeneration.
Analysis of the retinal gene expression profile after hypoxic preconditioning identifies candidate genes for neuroprotection.
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View SamplesPeripheral blood neutrophils were isolated from septic patients and treated in vitro with LPS or HMGB1
HMGB1 and LPS induce distinct patterns of gene expression and activation in neutrophils from patients with sepsis-induced acute lung injury.
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View SamplesWe developed a computational framework that integrates chromosomal copy number and gene expression data for detecting aberrations that promote cancer progression. We demonstrate the utility of this framework using a melanoma dataset. Our analysis correctly identified known drivers of melanoma and predicted multiple novel tumor dependencies. Two dependencies, TBC1D16 and RAB27A, confirmed empirically, suggest that abnormal regulation of protein trafficking contributes to proliferation in melanoma. Together, these results demonstrate the ability of integrative Bayesian approaches to identify novel candidate drivers with biological, and possibly therapeutic, importance in cancer.
An integrated approach to uncover drivers of cancer.
Cell line
View SamplesBackground and aims: Hepatitis C virus (HCV) infection is a major cause of liver disease including steatosis, fibrosis and liver cancer. Viral cure cannot fully eliminate the risk of disease progression and hepatocellular carcinoma (HCC) in advanced liver disease. The mechanisms for establishment of infection, liver disease progression and hepatocarcinogenesis are only partially understood. To address these questions, we probed the functional proteogenomic architecture of HCV infection within a hepatocyte-model. Methods: Time-resolved HCV infection of hepatocyte-like cells was analyzed by RNA sequencing, proteomics, metabolomics, and leveraged by integrative genomic analyses. Using differential expression, gene set enrichment analyses, and protein-protein interaction mapping we identified pathways relevant for liver disease pathogenesis that we validated in livers of 216 cirrhotic patients with HCV. Results: We uncovered marked changes in the protein expression of gene sets involved in innate immunity, metabolism and hepatocarcinogenesis. In infected cells, HCV enhances glucose metabolism and creates a Warburg-like shift of the lactate flux. HCV infection impaired the formation of peroxisomes -organelles required for long-chain fatty acid oxidation- causing intracellular fatty acid accumulation, which is a hallmark of non-alcoholic fatty liver disease (NAFLD). Ex vivo studies confirmed perturbed peroxisomes and revealed an association of hepatic catalase expression with clinical outcomes and phenotypes in HCV-associated cirrhosis, NAFLD and HCC cohorts. Conclusion: Our integrative analyses uncover how HCV perturbs the hepatocyte cell circuits to drive chronic liver disease and hepatocarcinogenesis. This proteogenomic atlas of HCV infection provides a model for the discovery of novel drivers for viral- and non-viral induced liver disease. Overall design: mRNA profiles of either mock or HCV-infected Huh7.5.1dif cells, performed in triplicates and collected every day between days 0 and 10 post infection. HCV infection reached plateau at day 7 post infection (pi). After day 7 pi unspecific effects cannot be excluded.
Combined Analysis of Metabolomes, Proteomes, and Transcriptomes of Hepatitis C Virus-Infected Cells and Liver to Identify Pathways Associated With Disease Development.
Cell line, Subject
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