Molecular topography of an entire nervous system
Ontology highlight
ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE136049 | GEO | 2019/08/21
REPOSITORIES: GEO
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Project description:<p>Lysosomes are key cellular organelles that metabolize extra- and intra-cellular substrates. Alterations in lysosomal metabolism are implicated in aging-associated metabolic and neurodegenerative diseases. However, how lysosomal metabolism actively coordinates the metabolic and nervous systems to regulate aging remains unclear. Here, we report a fat-to-neuron lipid signaling pathway induced by lysosomal metabolism and its longevity promoting role in <em>Caenorhabditis elegans</em>. We discovered that induced lysosomal lipolysis in peripheral fat storage tissue up-regulates the neuropeptide signaling pathway in the nervous system to promote longevity. This cell-non-autonomous regulation is mediated by a 47 specific polyunsaturated fatty acid, dihomo-gamma-linolenic acid (DGLA) and LBP-3 lipid chaperone protein transporting from the fat storage tissue to neurons. LBP-3 binds to DGLA, and acts through NHR-49 nuclear receptor and NLP-11 neuropeptide in neurons to extend lifespan. These results reveal lysosomes as a signaling hub to coordinate metabolism and aging, and lysosomal signaling mediated inter-tissue communication in promoting longevity.</p>
2022-05-06 | MTBLS4654 | MetaboLights
Project description:Motor neurons (MNs) are the cellular targets of multiple adult-onset diseases. Because distinct MN populations differ in disease susceptibility, it is important to define in animal models the degree of diversity within adult MNs. Here, we generated a comprehensive molecular resource of adult MNs in C. elegans. Single-cell RNA-sequencing of 12,603 cells revealed that all eight morphologically defined MN classes of the ventral nerve cord and its flanking ganglia subdivide into 29 distinct subclasses, almost quadrupling the degree of their previously described diversity. We find that four of the six C. elegans Hox genes delineate most, but not all MN subclasses. Strikingly, all 29 subclasses are delineated by unique expression codes of neuropeptide genes and receptors, critical for extra-synaptic (wireless) signaling. Leveraging the C. elegans connectome, we found a strong correlation between molecularly and connectivity defined MN subclasses. Beyond providing a valuable resource and searchable database (spinalcordatlas.com), our study identifies Hox and neuropeptide codes as key molecular descriptors of adult MN diversity, codes likely conserved in MNs across species.
2023-06-26 | GSE234962 | GEO
Project description:The nervous system of animals is functional at early postembryonic stages but undergoes extensive anatomical and functional changes throughout postembryonic development to eventually form a fully mature nervous system at adulthood. The molecular changes in post-mitotic neurons across post-embryonic development and the genetic programs that control these temporal transitions are not well understood. Using the model organism C. elegans, we comprehensively characterized the distinct functional states (locomotor behavior) and corresponding distinct molecular states (transcriptome) of the post-mitotic nervous system across temporal transitions from early post-embryonic periods to adulthood. We observed pervasive changes in gene expression, many of which controlled by the conserved heterochronic miRNA lin-4/mir-125 and its target, the transcription factor lin-14. The functional relevance of these molecular, lin-4/lin-14 controlled transitions are exemplified by a novel neuropeptide, nlp-45, which confers temporally controlled anti-exploratory activities. Our studies provide new insights into a perhaps generalizable regulatory mechanism that alters neuron-type specific gene batteries to modulate distinct behaviors states, and also provides a rich atlas of post-embryonic molecular changes to uncover additional regulatory mechanisms.
2021-10-25 | GSE158274 | GEO
Project description:The nervous system of animals is functional at early postembryonic stages but undergoes extensive anatomical and functional changes throughout postembryonic development to eventually form a fully mature nervous system at adulthood. The molecular changes in post-mitotic neurons across post-embryonic development and the genetic programs that control these temporal transitions are not well understood. Using the model organism C. elegans, we comprehensively characterized the distinct functional states (locomotor behavior) and corresponding distinct molecular states (transcriptome) of the post-mitotic nervous system across temporal transitions from early post-embryonic periods to adulthood. We observed pervasive changes in gene expression, many of which controlled by the conserved heterochronic miRNA lin-4/mir-125 and its target, the transcription factor lin-14. The functional relevance of these molecular, lin-4/lin-14 controlled transitions are exemplified by a novel neuropeptide, nlp-45, which confers temporally controlled anti-exploratory activities. Our studies provide new insights into a perhaps generalizable regulatory mechanism that alters neuron-type specific gene batteries to modulate distinct behaviors states, and also provides a rich atlas of post-embryonic molecular changes to uncover additional regulatory mechanisms.
2021-10-25 | GSE181288 | GEO
Project description:Background: With its fully sequenced genome and simple, well-defined nervous system, the nematode C. elegans offers a unique opportunity to correlate gene expression with neuronal differentiation. The lineal origin, cellular morphology and synaptic connectivity of each of the 302 neurons are known. In many instances, specific behaviors can be attributed to particular neurons or circuits. Here we describe microarray-based methods that monitor gene expression in C. elegans neurons and thereby link comprehensive profiles of neuronal transcription to key developmental and functional attributes of the nervous system. Results: We employed complementary microarray-based strategies to profile gene expression in the embryonic and larval nervous systems. In the MAPCeL (Micro-Array Profiling C. elegans Cells) method, we used Fluorescence Activated Cell Sorting (FACS) to isolate GFP-tagged embryonic neurons for microarray analysis. To profile the larval nervous system, we used the mRNA-tagging technique in which an epitope-labeled mRNA binding protein (FLAG-PAB-1) was transgenically expressed in neurons for immunoprecipitation of cell-specific transcripts. These combined approaches identified approximately 2,500 mRNAs that are highly enriched in either the embryonic or larval C. elegans nervous system. These data are validated in part by the detection of gene classes (e.g. transcription factors, ion channels, synaptic vesicle components) with established roles in neuronal development or function. In addition to utilizing these profiling approaches to define stage specific gene expression, we also applied the mRNA-tagging method to fingerprint a specific neuron type, the A-class group of cholinergic motor neurons, during early larval development. A comparison of these data to a MAPCeL profile of embryonic A-class motor neurons identified genes with common functions in both types of A-class motor neurons as well as transcripts with roles specific to each motor neuron type. Conclusion: We describe microarray-based strategies for generating expression profiles of embryonic and larval C. elegans neurons. These methods can be applied to particular neurons at specific developmental stages and therefore provide an unprecedented opportunity to obtain spatially and temporally defined snapshots of gene expression in a simple model 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 the entire nervous system at two developmental timepoints. To isolate transcripts from embryonic neurons we employed the MAPCeL (Microarray Profiling C. elegans Cells) technique in which pan-neuronal GFP+ cells are captured by FACS for RNA isolation. Since postembryonic cells are unattainable via this method, we used mRNA-tagging to isolated pan-neural RNAs from larval animals. In short, an epitope tagged poly-A binding protein (FLAG-PAB-1) was driven in all neurons using the F25B3.3 promoter. Following formaldehyde cross-linking, animals were passed through a French press and Dounce homogenized to isolate a cell-free extract. Anti-FLAG antibodies were incubated with the cell-free extract to capture FLAG-PAB bound RNAs. After elution and reversal of the crosslinks, RNAs are isolated by TriZOL extraction. We also identified transcripts enriched in a subset of C. elegans larval neurons, the A-class neurons (using unc-4::3xFLAG::PAB-1). Experiment Overall Design: 3 sets of experiments normalized separately by RMA Experiment Overall Design: larval references of sets 2 and 3 originate from the same hybridizations (accompanying CEL files are identical)
2008-06-15 | E-GEOD-8004 | biostudies-arrayexpress
Project description:Background: With its fully sequenced genome and simple, well-defined nervous system, the nematode C. elegans offers a unique opportunity to correlate gene expression with neuronal differentiation. The lineal origin, cellular morphology and synaptic connectivity of each of the 302 neurons are known. In many instances, specific behaviors can be attributed to particular neurons or circuits. Here we describe microarray-based methods that monitor gene expression in C. elegans neurons and thereby link comprehensive profiles of neuronal transcription to key developmental and functional attributes of the nervous system. Results: We employed complementary microarray-based strategies to profile gene expression in the embryonic and larval nervous systems. In the MAPCeL (Micro-Array Profiling C. elegans Cells) method, we used Fluorescence Activated Cell Sorting (FACS) to isolate GFP-tagged embryonic neurons for microarray analysis. To profile the larval nervous system, we used the mRNA-tagging technique in which an epitope-labeled mRNA binding protein (FLAG-PAB-1) was transgenically expressed in neurons for immunoprecipitation of cell-specific transcripts. These combined approaches identified approximately 2,500 mRNAs that are highly enriched in either the embryonic or larval C. elegans nervous system. These data are validated in part by the detection of gene classes (e.g. transcription factors, ion channels, synaptic vesicle components) with established roles in neuronal development or function. In addition to utilizing these profiling approaches to define stage specific gene expression, we also applied the mRNA-tagging method to fingerprint a specific neuron type, the A-class group of cholinergic motor neurons, during early larval development. A comparison of these data to a MAPCeL profile of embryonic A-class motor neurons identified genes with common functions in both types of A-class motor neurons as well as transcripts with roles specific to each motor neuron type. Conclusion: We describe microarray-based strategies for generating expression profiles of embryonic and larval C. elegans neurons. These methods can be applied to particular neurons at specific developmental stages and therefore provide an unprecedented opportunity to obtain spatially and temporally defined snapshots of gene expression in a simple model nervous system. Keywords: nervous system, development
2007-06-25 | GSE8004 | GEO
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.
2008-06-16 | E-GEOD-8159 | biostudies-arrayexpress
Project description:Panneuronally expressed genes, such as genes involved in the synaptic vesicle release cycle or in neuropeptide maturation, are critical for proper function of all neurons, but the transcriptional control mechanisms that direct such genes to all neurons of a nervous system remain poorly understood in any organism. We show here that six members of the CUT superfamily of homeobox genes, which are each panneuronally expressed, control panneuronal identity specification in C. elegans. Single mutants show barely any effects on panneuronal gene expression or global nervous system function, but such effects become apparent and progressively worsen upon removal of additional CUT family members. Phenotypes of compound mutants can be rescued non-discriminately by overexpression of individual family members, indicating that gene dosage is critical for CUT gene function. Genome-wide binding profiles as well as mutation of CUT binding sites by CRISPR/Cas9 genome engineering show that CUT genes directly control the expression of panneuronal features. Lastly, we found that CUT genes act in conjunction with neuron-type specific transcription factors to control panneuronal gene expression. In conclusion, our study provides a previously missing key insight into how neuronal gene expression programs are specified and reveals a highly buffered and robust mechanism that controls the most critical functional features of all neurons.
2022-03-07 | GSE188489 | GEO
Project description:During their lifetime, animals must adapt their behavior to survive in changing environments. This ability requires the nervous system to adjust through dynamic expression of neurotransmitters and receptors but also through growth, spatial reorganization and connectivity while integrating external stimuli. For instance, despite having a fixed neuronal cell lineage, the nematode Caenorhabditis elegans’ nervous system remains plastic throughout its development. Here, we focus on a specific example of nervous system plasticity, the C. elegans dauer exit decision. Under unfavorable conditions, larvae will enter the non-feeding and non-reproductive dauer stage and adapt their behavior to cope with a new environment. Upon improved conditions, this stress resistant developmental stage is actively reversed to resume reproductive development. However, how different environmental stimuli regulate the exit decision mechanism and thereby drive the larva’s behavioral change is unknown. To fill this gap, we developed a new open hardware method for long-term imaging (12h) of C.elegans larvae. We identified dauer-specific behavioral motifs and characterized the behavioral trajectory of dauer exit in different environments to identify key decision points. Combining long-term behavioral imaging with transcriptomics, we find that bacterial ingestion triggers a change in neuropeptide gene expression to establish post-dauer behavior. Taken together, we show how a developing nervous system can robustly integrate environmental changes, activate a developmental switch and adapt the organism’s behavior to a new environment.
2022-09-29 | GSE214208 | GEO
Project description:Neuropeptides constitute a vast and functionally diverse family of neurochemical signaling molecules, and are widely involved in the regulation of various physiological processes. The nematode C. elegans is well-suited for the study of neuropeptide biochemistry and function, as neuropeptide biosynthesis enzymes are not essential for C. elegans viability. This permits the study of neuropeptide biosynthesis in mutants lacking certain neuropeptide-processing enzymes. Mass spectrometry has been used to study the effects of proprotein convertase and carboxypeptidase mutations on proteolytic processing of neuropeptide precursors and on the peptidome in C. elegans. However, the enzymes required for the last step in the production of many bioactive peptides – the carboxyterminal amidation reaction – have not been characterized in this manner. Here, we describe three genes that encode homologs of neuropeptide amidation enzymes in C. elegans and used tandem LC-MS to compare neuropeptides in wild-type animals with those in newly generated mutants for these putative amidation enzymes. We report that mutants lacking both a functional peptidylglycine α-hydroxylating monooxygenase (PHM) and a peptidylglycine α-amidating monooxygenase (PAM) had a severely altered neuropeptide profile and also a decreased number of offspring. Interestingly, single mutants of the amidation enzymes still expressed some fully processed amidated neuropeptides, indicating the existence of a redundant amidation mechanism in C. elegans. In summary, the key steps in neuropeptide-processing in C. elegans seem to be executed by redundant enzymes, and loss of these enzymes severely affects brood size, supporting the need of amidated peptides for C. elegans reproduction.
2018-03-12 | PXD008942 | Pride