Drosophila melanogaster neural stem cells (neuroblasts [NBs]) divide asymmetrically by differentially segregating protein determinants into their daughter cells. Although the machinery for asymmetric protein segregation is well understood, the events that reprogram one of the two daughter cells toward terminal differentiation are less clear. In this study, we use time-resolved transcriptional profiling to identify the earliest transcriptional differences between the daughter cells on their way toward distinct fates. By screening for coregulated protein complexes, we identify vacuolar-type H+–ATPase (v-ATPase) among the first and most significantly down-regulated complexes in differentiating daughter cells. We show that v-ATPase is essential for NB growth and persistent activity of the Notch signaling pathway. Our data suggest that v-ATPase and Notch form a regulatory loop that acts in multiple stem cell lineages both during nervous system development and in the adult gut. We provide a unique resource for investigating neural stem cell biology and demonstrate that cell fate changes can be induced by transcriptional regulation of basic, cell-essential pathways. Overall design: Comparison of transcriptomes of wild-type type I NBs and GMCs of different ages (1.5h, 3h or 5h old) isolated by FACS from Drosophila melanogaster larval brains.
Time-resolved transcriptomics in neural stem cells identifies a v-ATPase/Notch regulatory loop.
Specimen part, Subject
View SamplesArabidopsis thaliana genes MLO2 (Mildew resistance locus-O 2), MLO6 and MLO12 exhibit unequal genetic redundancy with respect to the modulation of defense responses against powdery mildew fungi and the control of developmental phenotypes such as premature leaf decay. We show that early chlorosis and necrosis of rosette leaves in mlo2 mlo6 mlo12 mutants reflects an authentic but untimely leaf senescence program. Comparative transcriptional profiling revealed that transcripts of several genes encoding tryptophan/indole biosynthetic enzymes hyper-accumulate during vegetative development in the mlo2 mlo6 mlo12 mutant. Elevated expression levels of these genes correlate with altered steady-state levels of several indolic metabolites, including the phytoalexin camalexin and indolic glucosinolates, during development in the mlo2 single and the mlo2 mlo6 mlo12 triple mutant. Results of genetic epistasis analysis suggest a decisive role for indolic metabolites in mlo2-conditioned antifungal defense against both biotrophic powdery mildews and a camalexin-sensitive strain of the necrotrophic fungus, Botrytis cinerea. The wound- and pathogen-responsive callose synthase Powdery mildew resistance 4/Glucan-synthase-like 5 (PMR4/GSL5) was found to be responsible for the spontaneous callose deposits in mlo2 mutant plants but dispensable for mlo2-conditioned penetration resistance. Our data strengthen the notion that powdery mildew resistance of mlo2 genotypes is based on the same defense execution machinery as innate antifungal immune responses that restrict invasion of non-adapted fungal pathogens.
Tryptophan-derived metabolites are required for antifungal defense in the Arabidopsis mlo2 mutant.
Specimen part, Time
View SamplesGenome-wide transcriptome analyses have allowed for systems- level insights into gene regulatory networks. Due to the limited depth of quantitative proteomics, however, our understanding of post-transcriptional gene regulation and its effects on protein complex stoichiometry are lagging behind. Here, we employ deep sequencing and iTRAQ technology to determine transcript and protein expression changes of a Drosophila brain tumour model at near genome-wide resolution. In total, we quantify more than 6,200 tissue-specific proteins, corresponding to about 70% of all transcribed protein-coding genes. Using our integrated data set, we demonstrate that post-transcriptional gene regulation varies considerably with biological function and is surprisingly high for genes regulating transcription. We combine our quantitative data with protein-protein interaction data and show that post-transcriptional mechanisms significantly enhance co-regulation of protein complex subunits beyond transcriptional co-regulation. Interestingly, our results suggest that only about 11% of the annotated Drosophila protein complexes are co-regulated in the brain. Finally, we refine the composition of some of these core protein complexes by analysing the co-regulation of potential subunits. Our comprehensive transcriptome and proteome data provide a rich resource for quantitative biology and offer novel insights into understanding post- transcriptional gene regulation in a tumour model. Overall design: Transcriptomes of 1-3 day old adult female Drosophila melanogaster heads of control and brat mutant were generated by deep sequencing, in triplicate, using Illumina GAIIx.
Transcriptome and proteome quantification of a tumor model provides novel insights into post-transcriptional gene regulation.
Subject
View SamplesDrosophila neuroblasts have emerged as a model for stem cell biology that is ideal for genetic analysis but is limited by the lack of cell-type specific gene expression data. Here, we describe a methodology to isolate large numbers of pure neuroblasts and differentiating neurons that retain both cell cycle and lineage characteristics. We determine transcriptional profiles by mRNA sequencing and identify 28 predicted neuroblast specific transcription factors, which can be arranged in a network containing hubs for Notch signaling, growth control and chromatin regulation. Overexpression and RNAi for these factors identify Klumpfuss as a regulator of self-renewal. We show that loss of Klu function causes premature differentiation while overexpression results in the formation of transplantable brain tumors. Our data represent a valuable resource for Drosophila developmental neurobiology and we describes methodology that can be applied to other invertebrate stem cell lineages as well. Overall design: comparison of transcriptomes of Drosophila melanogaster larval neuroblasts and their differentiated daughter cells (neurons)
FACS purification and transcriptome analysis of drosophila neural stem cells reveals a role for Klumpfuss in self-renewal.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Chromatinized protein kinase C-θ directly regulates inducible genes in epithelial to mesenchymal transition and breast cancer stem cells.
Cell line, Treatment
View SamplesEpithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. The epithelial cell line MCF7, can be induced to undergo EMT with the induction of PKC by PMA. 5-10% of the resulting cells have a CSC phenotype. This study looks at the transcriptome of these cells and how it differs from cells with a non-CSC phenotype.
Chromatinized protein kinase C-θ directly regulates inducible genes in epithelial to mesenchymal transition and breast cancer stem cells.
Cell line, Treatment
View SamplesEarly innate lymphoid progenitors (EILP) have recently been identified in the mouse adult bone marrow as a multipotential progenitor population committed to ILC lineages, but their relationship with other described ILC progenitors is still unclear. In this study, we examine the progenitor-successor relationships between EILP, IL-7R+ common lymphoid progenitors (ALP), and ILC precursors (ILCp). Bioinformatic, phenotypical, functional, and genetic approaches collectively establish EILP as an intermediate progenitor between ALP and ILCp. Our work additionally provides new candidate regulators of ILC development and clearly defines the stage of requirement of transcription factors key for early ILC development. Overall design: transcriptional profiling of early ILC progenitors (EILP, ILCp), and common lymphoid progenitors (ALP) was performed by RNA sequencing
Development and differentiation of early innate lymphoid progenitors.
Specimen part, Cell line, Subject
View SamplesMembrane estrogen receptor (ER) alpha stimulates AMP kinase to suppress SREBP1 processing and lipids in liver
Estrogen reduces lipid content in the liver exclusively from membrane receptor signaling.
Specimen part
View SamplesThe recently released Affymetrix Human Gene 1.0 ST array has two major differences compared with standard 3' based arrays: (1) it interrogates the entire mRNA transcript, and (2) it uses cDNA targets. To assess the impact of these differences on array performance, we performed series of comparative hybridizations between the Human Gene 1.0 ST and the Affymetrix HG-U133 Plus 2.0 and the Illumina HumanRef-8 BeadChip arrays. Additionally, both cRNA and cDNA targets were probed on the HG-U133 Plus 2.0 array. The results show that the overall reproducibility is best using the Gene 1.0 ST array. When looking only at the high intensity probes, the reproducibility of the Gene 1.0 ST array and the Illumina BeadChip array is equally good. Concordance of array results was assessed using different inter-platform mappings. The Gene 1.0 ST is most concordant with the HG-U133 array hybridized with cDNA targets, thus showing the impact of the target type. Agreements are better between platforms with designs which choose probes from the 3' end of the gene. Overall, the high degree of correspondence provides strong evidence for the reliability of the Gene 1.0 ST array.
Affymetrix Whole-Transcript Human Gene 1.0 ST array is highly concordant with standard 3' expression arrays.
No sample metadata fields
View SamplesWe recently reported that single-cell derived isogenic subclones of SKMEL5 cells have differential initial sensitivity to BRAF-inhibitors. In order to probe differences among these subclones, we selected three subclones with unique drug responses: progressing (SK-MEL-5 SC10), stationary (SK-MEL-5 SC07), and regressing (SK-MEL-5 SC01) and performed RNASeq. This study examines differentially expressed genes (DEGs) among the subclones to identify the molecular basis for initial differences in drug sensitivity. Overall design: Transcriptomics analysis between single-cell derived isogenic subclones of BRAF-mutated melanoma cell line, SK-MEL-5
A Nonquiescent "Idling" Population State in Drug-Treated, BRAF-Mutated Melanoma.
Specimen part, Cell line, Subject
View Samples