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: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:RNA sequence was performed using mRNAs of motor neurons derived from iPSCs of four patients of spinal bulbar muscular atrophy (SBMA) and four age- and sex- matched controls. The analysis was performed using purified motor neurons by flowcytometry and cell sorting based on the expression of HB9e438::Venus reporter gene (P4) or unpurified motor neurons (NT).
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:In our original grant we proposed to use the NR3B-null mouse model to study the role of NR3B subunit in motor neuron function. We have now successfully generated NR3B null mice. Interestingly, NR3B-null mice invariably die at age P4-P8. Our preliminary examination indicates that the motor strength of these mice is severely impaired prior to death. As we continue to explore the cause of death in NR3B null mice, we propose to conduct gene profiling experiments to search for transcription changes in the brain related to ablation of the NR3B gene. We have used the facility provided by the NINDS/NIMH Microarray Consortium to identify genes that show abnormal expression patterns in these mice. We would like to compare these changes with that opccured in SOD1 mice, a mouse model of motor neuron diseases. Analysis of these genes will help to identify changes in networks and pathways that may cause the death of NR3B-null mice. These studies will further help to elucidate the functional role of NR3B in motor neurons. We will compare samples from motor neurons of wild type and SOD1 mice to identify genes that show abnormal expression patterns, which may be implicated in the death of SOD1 mice and shared with the same changes in NR3B-null mice. We hypothesize that genes with their transcription level changing significantly by ablation of NR3B will be associated with the molecular mechanism underlying the death of motor neurons in NR3B null mice. As NR3B is expressed primarily in the motor neurons of hindbrain and spinal cord, we have first collected and analyzed the spinal cord samples from NR3B null mice and wild-type controls in P4, an age of disease onset. We like to compare motor neuron and spinal cord smaples from SOD1 mice at the age prior to the disease onset. Total RNA from total 12 samples will be purified from ~200 motor neurons obtained by Laser Capture Microdissection and the total spinal cord. Extracted RNAs will be subjected to one or two rounds of amplification and the obtained cRNA will be biotinylated. The purified cRNA will be sent to the NINDS/NIMH Microarray Consortium be used to hybridize the GeneChip Mouse Genome 430 2.0 Array. The hybridization, scanning, and initial data analysis of these GeneChips will be conducted by the Consortium staff. We will analyze the collected data further after data collection. We will first identify genes that show significant changes between wild-type and SOD1 mice and then compare that with the result from NR3B null mice.
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.
Project description:The expression of v5-tagged Hoxc9 is induced and ChIP-seq is used to profile genome-wide occupancy in differentiating motor neurons The differentiation of ventral motor neurons is induced by treating embryonic stem cell cultures with retinoic acid and hedgehog signaling. Here, ChIP-seq is used to profile the genome-wide occupancy of Hoxc9 after five days of differentiation.