Project description:To determine target genes, biological functions of Jun and mechanisms of gene regulation by Jun in regenerating neurons, gene expression profiling was carried out of axotomized and uninjured facial motor neurons in floxed c-Jun mice crossed with nestin-cre mice. Nestin-promoter-driven Cre ensures deletion of Jun in the central nervous system including facial motor neurons. KO animals were Jun Flox/Fox Cre+, while WT animals were Jun Flox/Flox, Cre-.
Project description:The motor neurons innervating the muscles of facial expression are organized into somatotopic hindbrain clusters termed subnuclei. Each of the medial, intermediate, dorsolateral, and lateral subnuclei gives rise to a specific branch of the facial motor nerve (cranial nerve VII). How subnucleus-specific gene expression could mediate the accurate development of facial nerve projections was not well understood. We isolated specific facial motor subnuclei from E16.5 hindbrain cryosections using laser capture microdissection, purified the total RNA and analyzed it on Affymetrix Mouse Genome 430 2.0 arrays.
Project description:The original objectives of the study were to identify surface markers specifically expressed in motor neurons. We now use the data to profile the expression of Cdk family members in motor neurons.
Project description:Background: Differential gene expression specifies the highly diverse cell types that constitute the nervous system. With its sequenced genome and simple, well-defined neuroanatomy, the nematode C. elegans is a useful model system in which to correlate gene expression with neuron identity. The UNC-4 transcription factor is expressed in thirteen embryonic motor neurons where it specifies axonal morphology and synaptic function. These cells can be marked with an unc-4::GFP reporter transgene. Here we describe a powerful strategy, Micro-Array Profiling of C. elegans cells (MAPCeL), and confirm that this approach provides a comprehensive gene expression profile of unc-4::GFP motor neurons in vivo. Results: Fluorescence Activated Cell Sorting (FACS) was used to isolate unc-4::GFP neurons from primary cultures of C. elegans embryonic cells. Microarray experiments detected 6,217 unique transcripts of which ~1,000 are enriched in unc-4::GFP neurons relative to the average nematode embryonic cell. The reliability of these data was validated by the detection of known cell-specific transcripts and by expression in UNC-4 motor neurons of GFP reporters derived from the enriched data set. In addition to genes involved in neurotransmitter packaging and release, the microarray data include transcripts for receptors to a remarkably wide variety of signaling molecules. The added presence of a robust array of G-protein pathway components is indicative of complex and highly integrated mechanisms for modulating motor neuron activity. Over half of the enriched genes (537) have human homologs, a finding that could reflect substantial overlap with the gene expression repertoire of mammalian motor neurons. Conclusion: We have described a microarray-based method, MAPCeL, for profiling gene expression in specific C. elegans motor neurons and provide evidence that this approach can reveal candidate genes for key roles in the differentiation and function of these cells. These methods can now be applied to generate a gene expression map of the C. elegans nervous system. Experiment Overall Design: Our goal is to profile gene expression throughout the nervous system of the model organism Caenorhabditis elegans. As a first goal, we profiled a single class of embryonic motor neurons. To isolate transcripts from thesec neurons we developed the MAPCeL (Microarray Profiling C. elegans Cells) technique in which unc-4::GFP+ cells are captured by FACS for RNA isolation. We verified these data by bioinformatic means and by in vivo validation by creating GFP reporters for a random set of genes in our enriched gene list.
Project description:Whole genome transcriptional profiling is used to compare ESTs found in cell bodies and processes of Aplysia motor neurons RNA samples derived from cell bodies or processes of Aplysia single cultured motor neurons were hybridized to custom Aplysia EST microarrays. Two-condition experiment; four biological replicates for each condition were reciprocally hybridized on each two-color array
Project description:Gene expression profiling has been performed previously on motor cortex and spinal cord homogenates and of sporadic ALS cases and controls, to identify genes and pathways differentially expressed in ALS. More recent studies have combined the use of laser capture microdissection (LCM) with gene expression profiling to isolate the motor neurons from the surrounding cells, such as microglia and astrocytes, in order to determine those genes differentially expressed in the vulnerable cell population – i.e. motor neuron. The aim of the present study is to combine LCM and microarray analysis to determine those genes and pathways differentially expressed in MNs from human SOD1-related MND and to establish potential pathways for therapeutic intervention. Keywords: Human motor neurons The aim of this study was to determine the gene expression profiles from a small subset of cases which all carry mutations in the SOD1 gene. Expression profiles from isolated motor neurons in SOD1-related ALS cases were compared to those from control motor neurons, in order to establish the pathways implicated in SOD1-related motor neuronal cell death. The 'control' samples were originally submitted to GEO as GSE19332.
Project description:Gene expression changes in spinal motor neurons of the SOD1G93A-transgenic model for ALS after treatment with G-CSF. To gain insight into the mode of action of G-CSF, we performed gene expression profiling on isolated lumbar motor neurons from SOD1G93A mice, the most frequently studied animal model for ALS, with and without G-CSF treatment. A first group of SOD1G93A and WT mice was included in the study at week 11 of age when SOD1G93A mice present no signs of motor dysfunction but subtle signs of denervation detectable by electromyography. The second cohort of mice was treated with G-CSF or vehicle from week 11 to week 15. At the time of study completion, SOD1G93A mice presented clear motor impairment and motor neuron degeneration is documented. This design should provide information on genes altered in motor neurons of SOD1G93A mice from the clinically non-symptomatic to an early symptomatic stage, and give insight into genes influenced by G-CSF treatment. We sampled 300 motoneurons per mouse spinal cord by laser microdissection.
Project description:The purpose of this array was to investigate age-dependent changes the transcriptome of a highly homogenous cell population (Drosophila motor neurons) in order to help understand the contribution of changes in gene expression to age-dependent motor deficiencies. Drosophila motor neurons expressing GFP (via the UAS-Gal4 binary expression system) were isolated using flow cytometry from flies that were 7, 35 or 45 days old. The microarray design was highly redundant for calcium-binding and ion channel genes as we had apriori reasons to believe changes in these genes would be important. The ages were chosen because previous work had identified a major shift in neurotransmitter release between the ages of 35 and 45 days in Drosophila motor neurons. Although no significant changes were identified in that window, several genes showed elevated expression in old (35 day and 45 day) motor neurons compared to young (7 day) including matrix metalloproteinase 1 (dMMP1).
Project description:Progenitor motor neurons can be generated with high-efficiency by differentiating ES cells in vitro in the presence of retinoic acid and hedgehog signalling. Here, we characterize the chromatin landscape associated with progenitor motor neurons (pMNs) in order to assess how histone modification domains shift during the differentiation process. In this study, we characterize the genomic occupancy of H3K27me3, H3K4me3, H3K79me2 and Pol2 using ChIP-seq in progenitor motor neurons that have been differentiated in vitro from ES cells. An appropriate whole-cell extract control experiment for these ChIP-seq experiments is also included.