Purpose: Communication between growth cones and their environment plays a central role in assembling neural circuits. We use Tandemly-Tagged Ribosome Affinity Purification (T-TRAP) of mRNA from R cells followed by RNA-seq for multiple time points during development to follow gene expression during target selection and synapse formation. Methods: We chose a ribosome trap method by modifying the N-terminus of the Drosophila ribosomal protein RpL10 with two tandemly arranged epitopes, 3X FLAG and GFP, separated by the Tobacco Etch Virus (TEV) protease site and expressed this in specific cell types using the GAL4/UAS system. cDNA libraries were prepared from mRNA associated with the affinity purified ribosomes and sequenced using an Illumina HiSeq 2000. We mapped raw reads to the D. melanogaster reference genome (release FB2013_01) with the gapped aligner Tophat. Only reads uniquely aligned were collected.Transcript expression levels were quantified using RPKM units using customized scripts written in Perl. Results: In this study, we observed massive changes in expression of cell surface proteins over short time scales (i.e. 5 fold differences in the expression of many hundreds of genes over 5 hr intervals) as R cell growth cones encounter the processes of many different neurons during their conversion from growth cones to synaptic terminals. In addition, to changes in transcripts encoding cell surface proteins, other mRNAs changed significantly as did non-coding RNAs (lincRNAs) associated with ribosomes. Although dramatic changes in transcript levels of presynaptic proteins were not observed preceding the onset of synapse formation, marked changes in the 3''-untranslated regions of these transcripts were seen. Conclusions: These studies provide a step towards merging traditional genetic and global genomic approaches to understanding cellular recognition underlying the assembly of neural circuits. Overall design: We chose 7 time points for RNA-seq analysis of R cells during pupal development corresponding to 24, 35, 40, 45, 53, 65 and 96 hrs after pupal formation (APF).
Rapid Changes in the Translatome during the Conversion of Growth Cones to Synaptic Terminals.
Age, Specimen part, Subject
View SamplesWhen the yeast Saccharomyces cerevisiae is subjected to increasing glycolytic fluxes under aerobic conditions, there is a threshold value of the glucose uptake rate at which the metabolism shifts from being purely respiratory to mixed respiratory and fermentative. This shift is characterized by ethanol production, a phenomenon known as the Crabtree effect due to its analogy with lactate overflow in cancer cells. It is well known that at high glycolytic fluxes there is glucose repression of respiratory pathways resulting in a decrease in the respiratory capacity. Despite many years of detailed studies on this subject, it is not known whether the onset of the Crabtree effect (or overflow metabolism) is due to a limited respiratory capacity or caused by glucose-mediated repression of respiration. We addressed this issue by increasing respiration in S. cerevisiae by introducing a heterologous alternative oxidase, and observed reduced aerobic ethanol formation. In contrast, increasing non-respiratory NADH oxidation by overexpression of a water-forming NADH oxidase reduced aerobic glycerol formation. The metabolic response to elevated alternative oxidase occurred predominantly in the mitochondria, while NADH oxidase affected genes that catalyze cytosolic reactions. Moreover, NADH oxidase restored the deficiency of cytosolic NADH dehydrogenases in S. cerevisiae. These results indicate that NADH oxidase localizes in the cytosol, while alternative oxidase is directed to the mitochondria. The onset of aerobic ethanol formation is demonstrated to be a consequence of an imbalance in mitochondrial redox balancing. In addition to answering fundamental physiological questions, our findings are relevant for all biomass derived applications of S. cerevisiae.
Increasing NADH oxidation reduces overflow metabolism in Saccharomyces cerevisiae.
No sample metadata fields
View SamplesMale Sprague-Dawley rats 8 weeks old, were adrenalectomized, treated with 300ug/kg corticosterone or vehicle 3 days after surgery then sacrificed 1 hour later. Hippocampi were removed and RNA extracted and processed for sequencing at the Massachusetts General Hospital Nex-Generation Sequening Core. Overall design: Includes 6 cort treated and 6 control biological replicates
Stress and corticosteroids regulate rat hippocampal mitochondrial DNA gene expression via the glucocorticoid receptor.
No sample metadata fields
View SamplesNaive pluripotent embryonic stem cells (ESCs) and embryonic germ cells (EGCs) are derived from the preimplantation epiblast and primordial germ cells (PGCs), respectively. We investigated whether differences exist between ESCs and EGCs, in view of their distinct developmental origins. PGCs are programmed to undergo global DNA demethylation; however, we find that EGCs and ESCs exhibit equivalent global DNA methylation levels. Importantly, inhibition of Erk and Gsk3b by 2i conditions leads to pronounced reduction in DNA methylation in both cell types. This is driven by Prdm14 and is associated with downregulation of Dnmt3a and Dnmt3b. However, genomic imprints are maintained in 2i, and we report derivation of EGCs with intact genomic imprints. Collectively, our findings establish that culture in 2i instills a naive pluripotent state with a distinctive epigenetic configuration that parallels molecular features observed in both the preimplantation epiblast and nascent PGCs.
Naive pluripotency is associated with global DNA hypomethylation.
Sex, Specimen part
View SamplesPurpose: Information processing in the brain relies on precise patterns of synapses between neurons. The molecular mechanisms by which this specificity is achieved remains elusive. In the medulla of the Drosophila visual system, different neurons form synaptic connections in different layers. Methods: we developed methods to purify seven neuronal cell types (R7, R8 and L1-L5 neurons) using Fluorescence Activated Cell Sorting. Results: we show that neurons with different synaptic specificities express unique combinations of mRNAs encoding hundreds of cell surface and secreted proteins. Using RNA sequencing and MiMIC-based protein tagging, we demonstrate that 21 paralogs of the Dpr family, a subclass of Immunoglobulin (Ig)-domain containing proteins, are expressed in unique combinations in homologous neurons with different layer-specific synaptic connections. Dpr interacting proteins (DIPs), comprising nine paralogs of another subclass of Ig superfamily proteins, are expressed in a complementary layer-specific fashion in a subset of synaptic partners. We propose that pairs of Dpr/DIP paralogs contribute to layer-specific patterns of synaptic connectivity. Conclusions: This complexity is mirrored by the complexity of the cell surface and secreted molecules expressed by each of the R cell and lamina neurons profiled in this study. How this complexity contributes to specificity remains elusive, but the convergence of improved histological, genetic and molecular tools promises to provide important insights into the molecular recognition strategies controlling synaptic specificity. Overall design: We chose 7 time points for RNA-seq analysis of R cells during pupal development corresponding to 24, 35, 40, 45, 53, 65 and 96 hrs after pupal formation (APF).
Ig Superfamily Ligand and Receptor Pairs Expressed in Synaptic Partners in Drosophila.
Age, Specimen part, Subject
View SamplesMany pathogens secrete toxins that target key host processes resulting in the activation of immune pathways. The secreted Pseudomonas aeruginosa toxin Exotoxin A (ToxA) disrupts intestinal protein synthesis which triggers the induction of a subset of P. aeruginosa-response genes in the nematode Caenorhabditis elegans. We found that losing one ToxA-induced C. elegans gene, the Tribbles pseudokinase ortholog nipi-3, results in hypersusceptibility to both P. aeruginosa and ToxA. We determined that NIPI-3 mediates the post-developmental expression of intestinal immune genes and proteins and primarily functions in parallel to known immune pathways, including p38 PMK-1 MAPK signaling. Here we present the microarray data that was used to determine that (1) nipi-3 regulates immune gene expression and that (2) nipi-3 and pmk-1 regulate non-overlapping gene sets consistent with them functioning in parallel.
Tribbles ortholog NIPI-3 and bZIP transcription factor CEBP-1 regulate a Caenorhabditis elegans intestinal immune surveillance pathway.
Specimen part
View SamplesExperiment to understand relationships between sheep rumen wall transcriptome and microbial methane emissions Overall design: RNA seq of ventral rumen wall of Australian sheep
Across-Experiment Transcriptomics of Sheep Rumen Identifies Expression of Lipid/Oxo-Acid Metabolism and Muscle Cell Junction Genes Associated With Variation in Methane-Related Phenotypes.
Subject
View SamplesLNCaP cells were maintained in charcoal-stripped serum containing medium for 48 hours and treated with vehicle or 10 uM of UT-69, UT-155, R-UT-155, or enzalutamide. Twenty four hours after treatment, the cells were harvested, RNA was isolated and expression of genes was measured using microarray (Affymetrix Clarion S)
Novel Selective Agents for the Degradation of Androgen Receptor Variants to Treat Castration-Resistant Prostate Cancer.
Cell line
View SamplesAnalysis of C4-2 prostate cancer cell line after 6 hrs of treatment with TOPK-32. PBK is overexpressed in a number of solid tumours, including prostate cancer. Results provide insight into the molecular mechanisms of PBK in prostate carcinogenesis. Overall design: This experiment was designed to understand the regulation of transcriptome by PDZ domain binding kinase, which is an important kinase with role in cell cycle. The cells were treated with a catalytic inhibitor TOPK32 which inhibits the kinase activity of PBK protein.
A reciprocal feedback between the PDZ binding kinase and androgen receptor drives prostate cancer.
No sample metadata fields
View SamplesAnalysis of C4-2 Prostate cancer cell line after 72 hours of knockdown. PBK is overexpressed in a number of solid tumours, including prostate cancer. Results provide insight into the molecular mechanisms of PBK in prostate carcinogenesis. Overall design: This experiment was designed to understand the regulation of transcriptiome by PDZ domain binding kinase (PBK), which is an important kinase with role in cell cycle. In order to achieve this, the endogenous protein was knocked down using siRNA pool that targets the PBK mRNA.
A reciprocal feedback between the PDZ binding kinase and androgen receptor drives prostate cancer.
No sample metadata fields
View Samples