Infection is a major complication and cause of mortality and morbidity after acute stroke however the mechanisms are poorly understood. After experimental stroke the microarchitecture and cellular composition of the spleen are extensively disrupted resulting in deficits to immune function.
Experimental Stroke Differentially Affects Discrete Subpopulations of Splenic Macrophages.
Specimen part, Treatment
View SamplesBackground: Transposable elements are known to influence the regulation of some genes. We aimed to determine which genes show altered gene expression when transposable elements are epigenetically activated.
Genome-wide identification of genes regulated in trans by transposable element small interfering RNAs.
Specimen part
View SamplesWe report the application of ultrashort metabolic labeling of RNA for high-throughput profiling of RNA processing in Drosophila S2 cells. Overall design: Examination of 3 different labeling timepoints in Drosophila S2 cells.
The kinetics of pre-mRNA splicing in the <i>Drosophila</i> genome and the influence of gene architecture.
Cell line, Subject
View SamplesRNA-seq transcriptome measurements are typically performed by isolating RNA from large numbers of cells in culture or tissues. While highly informative, such experiments mask the variability in gene expression patterns that exists between individual cells. To gain insight into the dynamics of gene expression on the level of single-cells, we have carried out the transcriptomes of single-cells from the GM12878 cell line using RNA-seq. Overall design: Single GM12878 cells were picked and RNA-seq libraries were generated using the SMART-seq protocol. We also carried out RNA-seq experiments on pools of 10, 30 and 100 cells, on 100pg and 10ng of total RNA, and on pools of 10 cells that were subsequently split into 10 separate sample and processed as if they were single cells in order to assess technical variation in our experiments.
From single-cell to cell-pool transcriptomes: stochasticity in gene expression and RNA splicing.
No sample metadata fields
View SamplesChromatin remodelling provides a key mechanism for the regulation of gene expression through dynamic alterations in nucleosome occupancy at promoters and enhancers. Haploinsufficiency for the ATP-dependent chromatin remodeller chromodomain-helicase-DNA-binding protein 7 (CHD7) causes human CHARGE syndrome. CHARGE is characterised by a distinct pattern of congenital anomalies, including cardiovascular malformations, and has traditionally been considered a neurocristopathy. We present a new perspective, by showing severe structural cardiovascular defects following ablation of Chd7 in the anterior mesoderm and other cardiac-related lineages. We identify multiple downstream pathways affected by the loss of Chd7 and disruption of excitation-contraction coupling in cardiomyocytes. Furthermore, we demonstrate CHD7 binding at the Sema3C promoter and alterations to the local chromatin structure in vivo, indicating direct transcriptional regulation. This work therefore provides novel insights into the etiology of heart defects arising in CHARGE syndrome and reveals a requirement for CHD7 activity in mesodermal cardiac progenitors.
A critical role for the chromatin remodeller CHD7 in anterior mesoderm during cardiovascular development.
Specimen part
View SamplesBAF57, a component of the SWI/SNF chromatin remodeling complex conglomerate,modulates androgen receptor activity to promote prostate cancer. However the molecular consequences of tumor associated BAF57 elevation have remianed undefined in advanced disease such as castration resistant prostate cancer and/or metastasis
Aberrant BAF57 signaling facilitates prometastatic phenotypes.
Specimen part, Treatment
View SamplesThe highly conserved Epidermal Growth Factor-receptor (Egfr) pathway is required in all animals for normal development and homeostasis; consequently, aberrant Egfr signaling is implicated in a number of diseases. Genetic analysis of Drosophila melanogaster Egfr has contributed significantly to understanding this conserved pathway and has led to the discovery of new components and targets. Here we used microarray analysis of Drosophila third instar wing discs, in which Egfr signaling was perturbed, to identify new Egfr-responsive genes. Upregulated transcripts included five known targets suggesting the approach was valid. We investigated the function of 29 previously uncharacterized genes, which had pronounced responses. The Egfr pathway is important for wing-vein patterning and using reverse genetic analysis we identified five genes that showed venation defects. Three of these genes are expressed in vein primordia and all showed transcriptional changes in response to altered Egfr activity consistent with being targets of the pathway. Genetic interactions with Egfr further linked two of the genes, Sulfated (Sulf1), an endosulfatase gene, and CG4096, an ADAMTS (A Disintegrin And Metalloproteinase with ThromboSpondin motifs) gene, to the pathway. Sulf1 showed a strong genetic interaction with the neuregulin-like ligand vein (vn) and may influence binding of Vn to heparan-sulfated proteoglycans (HSPGs). Genetic evidence also shows that CG4096 functions by modulating activity of the Egfr ligands. The substrate(s) and how ligand activity is affected are unknown, but interestingly vertebrate EGF ligands are regulated by a related ADAMTS protein. We conclude Sulf1 and CG4096 are negative feedback regulators of Egfr signaling that function in the extracellular space to influence ligand activity.
New negative feedback regulators of Egfr signaling in Drosophila.
Specimen part
View SamplesIt is well-established that neurons in the adult mammalian central nervous system are terminally differentiated and, if injured, will be unable to regenerate their connections. In contrast to mammals, zebrafish and other teleosts display a robust neuroregenerative response. Following optic nerve crush (ONX), retinal ganglion cells (RGC) regrow their axons to synapse with topographically correct targets in the optic tectum, such that vision is restored in ~21 days. What accounts for these differences between teleostean and mammalian responses to neural injury is not fully understood. A time course analysis of global gene expression patterns in the zebrafish eye after optic nerve crush can help to elucidate cellular and molecular mechanisms that contribute to a successful neuroregeneration.
Time Course Analysis of Gene Expression Patterns in Zebrafish Eye During Optic Nerve Regeneration.
Specimen part
View SamplesTransfer cells (TCs) play important roles in facilitating enhanced rates of nutrient transport at key apoplasmic/symplasmic junctions along the nutrient acquisition and transport pathways in plants. TCs achieve this capacity by developing elaborate wall ingrowth networks which serve to increase plasma membrane surface area thus increasing the cell's surface area-to-volume ratio to achieve increased flux of nutrients across the plasma membrane. Phloem parenchyma (PP) cells of Arabidopsis leaf veins trans-differentiate to become PP TCs which likely function in a two-step phloem loading mechanism by facilitating unloading of photoassimilates into the apoplasm for subsequent energy-dependent uptake into the sieve element/companion cell (SE/CC) complex. We are using PP TCs in Arabidopsis as a genetic model to identify transcription factors involved in coordinating deposition of the wall ingrowth network. Confocal imaging of pseudo-Schiff propidium iodide-stained tissue revealed different profiles of temporal development of wall ingrowth deposition across maturing cotyledons and juvenile leaves, and a basipetal gradient of deposition across mature adult leaves. RNA-Seq analysis was undertaken to identify differentially expressed genes common to these three different profiles of wall ingrowth deposition. This analysis identified 68 transcription factors up-regulated two-fold or more in at least two of the three experimental comparisons, with six of these transcription factors belonging to Clade III of the NAC-domain family. Phenotypic analysis of these NAC genes using insertional mutants revealed significant reductions in levels of wall ingrowth deposition, particularly in a double mutant of NAC056 and NAC018, as well as compromised sucrose-dependent root growth, indicating impaired capacity for phloem loading. Collectively, these results support the proposition that Clade III members of the NAC domain family in Arabidopsis play important roles in regulating wall ingrowth deposition in PP TCs. Overall design: The sampling enabled three different temporal and spatial pair-wise comparisons for RNA-Seq analysis, namely: (i) cotyledons at Day 5 vs Day 10; (ii) Leaf 1 and Leaf 2 (first juvenile leaves) at Day 10 vs Day 16; and (iii) basal vs apical third (base vs tip) of Leaf 12 at Day 31. This analysis provided temporal and spatial comparisons of tissues with absent vs abundant wall ingrowth deposition in phloem parenchyma transfer cells.
Transcript Profiling Identifies NAC-Domain Genes Involved in Regulating Wall Ingrowth Deposition in Phloem Parenchyma Transfer Cells of <i>Arabidopsis thaliana</i>.
Specimen part, Subject
View SamplesSubpopulations of human fetal thymocyte and circulating nave T cells were obtained through FACS sorting, including CD3-CD4+CD8- intrathymic T progenitor cells (ITTP), CD3intCD4+CD8+ "double positive" thymocytes (DP), CD3highCD4+CD8- "single positive" thymocytes (SP4), CD3+CD4+CD8-CD45RA+CD62L+ nave T cells from cord blood (CB4+), and CD3+CD4+CD8-CD45RA+CD62L+ nave T cells from adult blood (AB4+).
Gene expression profiles during human CD4+ T cell differentiation.
No sample metadata fields
View Samples