1
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. Front Cell Dev Biol 2024; 12:1389077. [PMID: 38946799 PMCID: PMC11211535 DOI: 10.3389/fcell.2024.1389077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the Caenorhabditis elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6, a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1, which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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Affiliation(s)
- Peter C Breen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Kendall G Kanakanui
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Martin A Newman
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Robert H Dowen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
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2
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Heiman MG, Bülow HE. Dendrite morphogenesis in Caenorhabditis elegans. Genetics 2024; 227:iyae056. [PMID: 38785371 PMCID: PMC11151937 DOI: 10.1093/genetics/iyae056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/02/2024] [Indexed: 05/25/2024] Open
Abstract
Since the days of Ramón y Cajal, the vast diversity of neuronal and particularly dendrite morphology has been used to catalog neurons into different classes. Dendrite morphology varies greatly and reflects the different functions performed by different types of neurons. Significant progress has been made in our understanding of how dendrites form and the molecular factors and forces that shape these often elaborately sculpted structures. Here, we review work in the nematode Caenorhabditis elegans that has shed light on the developmental mechanisms that mediate dendrite morphogenesis with a focus on studies investigating ciliated sensory neurons and the highly elaborated dendritic trees of somatosensory neurons. These studies, which combine time-lapse imaging, genetics, and biochemistry, reveal an intricate network of factors that function both intrinsically in dendrites and extrinsically from surrounding tissues. Therefore, dendrite morphogenesis is the result of multiple tissue interactions, which ultimately determine the shape of dendritic arbors.
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Affiliation(s)
- Maxwell G Heiman
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA 02115, USA
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Hannes E Bülow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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3
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Ouzounidis VR, Green M, van Capelle CDC, Gebhardt C, Crellin H, Finlayson C, Prevo B, Cheerambathur DK. The outer kinetochore components KNL-1 and Ndc80 complex regulate axon and neuronal cell body positioning in the C. elegans nervous system. Mol Biol Cell 2024; 35:ar83. [PMID: 38656792 PMCID: PMC11238089 DOI: 10.1091/mbc.e23-08-0325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024] Open
Abstract
The KMN (Knl1/Mis12/Ndc80) network at the kinetochore, primarily known for its role in chromosome segregation, has been shown to be repurposed during neurodevelopment. Here, we investigate the underlying neuronal mechanism and show that the KMN network promotes the proper axonal organization within the C. elegans head nervous system. Postmitotic degradation of KNL-1, which acts as a scaffold for signaling and has microtubule-binding activities at the kinetochore, led to disorganized ganglia and aberrant placement and organization of axons in the nerve ring - an interconnected axonal network. Through gene-replacement approaches, we demonstrate that the signaling motifs within KNL-1, responsible for recruiting protein phosphatase 1, and activating the spindle assembly checkpoint are required for neurodevelopment. Interestingly, while the microtubule-binding activity is crucial to KMN's neuronal function, microtubule dynamics and organization were unaffected in the absence of KNL-1. Instead, the NDC-80 microtubule-binding mutant displayed notable defects in axon bundling during nerve ring formation, indicating its role in facilitating axon-axon contacts. Overall, these findings provide evidence for a noncanonical role for the KMN network in shaping the structure and connectivity of the nervous system in C. elegans during brain development.
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Affiliation(s)
- Vasileios R. Ouzounidis
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Mattie Green
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Charlotte de Ceuninck van Capelle
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Clara Gebhardt
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Helena Crellin
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Cameron Finlayson
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Bram Prevo
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Dhanya K. Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
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4
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Shi R, Ho XY, Tao L, Taylor CA, Zhao T, Zou W, Lizzappi M, Eichel K, Shen K. Stochastic growth and selective stabilization generate stereotyped dendritic arbors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.591205. [PMID: 38766073 PMCID: PMC11100716 DOI: 10.1101/2024.05.08.591205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Stereotyped dendritic arbors are shaped by dynamic and stochastic growth during neuronal development. It remains unclear how guidance receptors and ligands coordinate branch dynamic growth, retraction, and stabilization to specify dendritic arbors. We previously showed that extracellular ligand SAX-7/LICAM dictates the shape of the PVD sensory neuron via binding to the dendritic guidance receptor DMA-1, a single transmembrane adhesion molecule. Here, we perform structure-function analyses of DMA-1 and unexpectedly find that robust, stochastic dendritic growth does not require ligand-binding. Instead, ligand-binding inhibits growth, prevents retraction, and specifies arbor shape. Furthermore, we demonstrate that dendritic growth requires a pool of ligand-free DMA-1, which is maintained by receptor endocytosis and reinsertion to the plasma membrane via recycling endosomes. Mutants defective of DMA-1 endocytosis show severely truncated dendritic arbors. We present a model in which ligand-free guidance receptor mediates intrinsic, stochastic dendritic growth, while extracellular ligands instruct dendrite shape by inhibiting growth.
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5
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590113. [PMID: 38712300 PMCID: PMC11071313 DOI: 10.1101/2024.04.18.590113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the C. elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6 , a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1 , which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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6
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Ramirez-Suarez NJ, Belalcazar HM, Rahman M, Trivedi M, Tang LTH, Bülow HE. Convertase-dependent regulation of membrane-tethered and secreted ligands tunes dendrite adhesion. Development 2023; 150:dev201208. [PMID: 37721334 PMCID: PMC10546877 DOI: 10.1242/dev.201208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 08/01/2023] [Indexed: 09/19/2023]
Abstract
During neural development, cellular adhesion is crucial for interactions among and between neurons and surrounding tissues. This function is mediated by conserved cell adhesion molecules, which are tightly regulated to allow for coordinated neuronal outgrowth. Here, we show that the proprotein convertase KPC-1 (homolog of mammalian furin) regulates the Menorin adhesion complex during development of PVD dendritic arbors in Caenorhabditis elegans. We found a finely regulated antagonistic balance between PVD-expressed KPC-1 and the epidermally expressed putative cell adhesion molecule MNR-1 (Menorin). Genetically, partial loss of mnr-1 suppressed partial loss of kpc-1, and both loss of kpc-1 and transgenic overexpression of mnr-1 resulted in indistinguishable phenotypes in PVD dendrites. This balance regulated cell-surface localization of the DMA-1 leucine-rich transmembrane receptor in PVD neurons. Lastly, kpc-1 mutants showed increased amounts of MNR-1 and decreased amounts of muscle-derived LECT-2 (Chondromodulin II), which is also part of the Menorin adhesion complex. These observations suggest that KPC-1 in PVD neurons directly or indirectly controls the abundance of proteins of the Menorin adhesion complex from adjacent tissues, thereby providing negative feedback from the dendrite to the instructive cues of surrounding tissues.
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Affiliation(s)
| | - Helen M. Belalcazar
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Maisha Rahman
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Meera Trivedi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Leo T. H. Tang
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Hannes E. Bülow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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7
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Tzeng CP, Shen K. Wnt signaling and contact-mediated repulsion shape sensory dendritic fields. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557812. [PMID: 37781584 PMCID: PMC10540810 DOI: 10.1101/2023.09.14.557812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The complete and non-redundant coverage of sensory tissues by neighboring neurons enables effective detection of stimuli in the environment. How the neurites of adjacent neurons establish their boundaries to achieve this completeness in coverage remains incompletely understood. Here, we use distinct fluorescent reporters to study two neighboring sensory neurons with complex dendritic arbors, FLP and PVD, in C. elegans . We quantify the sizes of their dendritic fields, and identify CWN-2/Wnt and LIN-17/Frizzled as a ligand and receptor that regulate the relative dendritic field sizes of these two neurons. Loss of either cwn-2 or lin-17 results in complementary changes in the size of the dendritic fields of both neurons; the FLP arbor expands, while that of PVD shrinks. Using an endogenous knock-in mNeonGreen-CWN-2/Wnt, we find that CWN-2/Wnt is localized along the path of growing FLP dendrites. Dynamic imaging shows a significant braking of FLP dendrite growth upon CWN-2/Wnt contact. We find that LIN-17/Frizzled functions cell-autonomously in FLP to limit dendritic field size and propose that PVD fills the space left by FLP through contact-induced retraction. Our results reveal that interactions of dendrites with adjacent dendrites and with environmental cues both shape the boundaries of neighboring dendritic fields. Highlights ▫ Secreted Wnt CWN-2 and cell-autonomous activity of neuronal LIN-17/Frizzled receptors restrict FLP dendritic field sizes▫ Endogenously tagged CWN-2/Wnt is punctate and visible in the same plane of growing FLP dendrites▫ Growth of developing FLP dendrites is inhibited upon contact with extracellular CWN-2/Wnt and with PVD dendrites.
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8
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Xie J, Zou W, Tugizova M, Shen K, Wang X. MBL-1 and EEL-1 affect the splicing and protein levels of MEC-3 to control dendrite complexity. PLoS Genet 2023; 19:e1010941. [PMID: 37729192 PMCID: PMC10511122 DOI: 10.1371/journal.pgen.1010941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 08/28/2023] [Indexed: 09/22/2023] Open
Abstract
Transcription factors (TFs) play critical roles in specifying many aspects of neuronal cell fate including dendritic morphology. How TFs are accurately regulated during neuronal morphogenesis is not fully understood. Here, we show that LIM homeodomain protein MEC-3, the key TF for C. elegans PVD dendrite morphogenesis, is regulated by both alternative splicing and an E3 ubiquitin ligase. The mec-3 gene generates several transcripts by alternative splicing. We find that mbl-1, the orthologue of the muscular dystrophy disease gene muscleblind-like (MBNL), is required for PVD dendrite arbor formation. Our data suggest mbl-1 regulates the alternative splicing of mec-3 to produce its long isoform. Deleting the long isoform of mec-3(deExon2) causes reduction of dendrite complexity. Through a genetic modifier screen, we find that mutation in the E3 ubiquitin ligase EEL-1 suppresses mbl-1 phenotype. eel-1 mutants also suppress mec-3(deExon2) mutant but not the mec-3 null phenotype. Loss of EEL-1 alone leads to excessive dendrite branches. Together, these results indicate that MEC-3 is fine-tuned by alternative splicing and the ubiquitin system to produce the optimal level of dendrite branches.
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Affiliation(s)
- Jianxin Xie
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Zou
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, United States of America
| | - Madina Tugizova
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, United States of America
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, California, United States of America
| | - Xiangming Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Department of Cell Biology, School of Basic Medical Science, Capital Medical University, Beijing, China
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9
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Fang J, Wang J, Wang Y, Liu X, Chen B, Zou W. Ribo-On and Ribo-Off tools using a self-cleaving ribozyme allow manipulation of endogenous gene expression in C. elegans. Commun Biol 2023; 6:816. [PMID: 37542105 PMCID: PMC10403566 DOI: 10.1038/s42003-023-05184-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 07/26/2023] [Indexed: 08/06/2023] Open
Abstract
Investigating gene function relies on the efficient manipulation of endogenous gene expression. Currently, a limited number of tools are available to robustly manipulate endogenous gene expression between "on" and "off" states. In this study, we insert a 63 bp coding sequence of T3H38 ribozyme into the 3' untranslated region (UTR) of C. elegans endogenous genes using the CRISPR/Cas9 technology, which reduces the endogenous gene expression to a nearly undetectable level and generated loss-of-function phenotypes similar to that of the genetic null animals. To achieve conditional knockout, a cassette of loxP-flanked transcriptional termination signal and ribozyme is inserted into the 3' UTR of endogenous genes, which eliminates gene expression spatially or temporally via the controllable expression of the Cre recombinase. Conditional endogenous gene turn-on can be achieved by either injecting morpholino, which blocks the ribozyme self-cleavage activity or using the Cre recombinase to remove the loxP-flanked ribozyme. Together, our results demonstrate that these ribozyme-based tools can efficiently manipulate endogenous gene expression both in space and time and expand the toolkit for studying the functions of endogenous genes.
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Affiliation(s)
- Jie Fang
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 322000, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, 310058, Hangzhou, China
- Department of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China
| | - Jie Wang
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 322000, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, 310058, Hangzhou, China
| | - Yuzhi Wang
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 322000, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, 310058, Hangzhou, China
| | - Xiaofan Liu
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 322000, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, 310058, Hangzhou, China
| | - Baohui Chen
- Department of Cell Biology and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China.
- Zhejiang Laboratory for Systems & Precision Medicine, Zhejiang University Medical Center, Hangzhou, China.
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, China.
- Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Hangzhou, China.
| | - Wei Zou
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, 322000, Yiwu, China.
- Institute of Translational Medicine, Zhejiang University, 310058, Hangzhou, China.
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10
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Sakai N, Sun P, Kim B, Emmons SW. Function of cell adhesion molecules in differentiation of ray sensory neurons in C. elegans. G3 (BETHESDA, MD.) 2023; 13:jkac338. [PMID: 36573343 PMCID: PMC9997551 DOI: 10.1093/g3journal/jkac338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 11/29/2022] [Indexed: 12/28/2022]
Abstract
For proper functioning of the nervous system, it is crucial that neurons find their appropriate partners and build the correct neural connection patterns. Although cell adhesion molecules (CAMs) have been studied for many years as essential players in neural connections, we have yet to unravel the code by which CAMs encode synaptic specificity. We analyzed the effects of mutations in CAM genes on the morphology and synapses of a set of sensory neurons in the Caenorhabditis elegans male tail. B-type ray sensory neurons express 10 genes encoding CAMs. We examined the effect on axon trajectory and localization of pre-synaptic components in viable mutants of nine of these. We found axon trajectory defects in mutants of UNC-40/DCC, SAX-3/ROBO, and FMI-1/Flamingo/Celsr1. None of the mutations caused loss of pre-synaptic components in axons, and in several the level even appeared to increase, suggesting possible accumulation of pre-synapses. B-type sensory neurons fasciculate with a second type of ray sensory neuron, the A-type, in axon commissures. We found a CAM expressed in A-type functions additively with a CAM expressed in B-type in axon guidance, and lack of a CAM expressed in B-type affected A-type axon guidance. Overall, single and multiple mutants of CAM genes had limited effects on ray neuron trajectories and accumulation of synaptic components.
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Affiliation(s)
- Naoko Sakai
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 162-8666, USA
- Department of Physiology, Tokyo Women’s Medical University School of Medicine, Shinjyuku, Tokyo 10326, Japan
| | - Peter Sun
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 162-8666, USA
| | - Byunghyuk Kim
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 162-8666, USA
- Department of Life Science, Dongguk University, Bronx 10461, South Korea
| | - Scott W Emmons
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York 162-8666, USA
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11
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Choi K, Kim WK, Hyeon C. Polymer Physics-Based Classification of Neurons. Neuroinformatics 2023; 21:177-193. [PMID: 36190621 DOI: 10.1007/s12021-022-09605-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2022] [Indexed: 11/26/2022]
Abstract
Recognizing that diverse morphologies of neurons are reminiscent of structures of branched polymers, we put forward a principled and systematic way of classifying neurons that employs the ideas of polymer physics. In particular, we use 3D coordinates of individual neurons, which are accessible in recent neuron reconstruction datasets from electron microscope images. We numerically calculate the form factor, F(q), a Fourier transform of the distance distribution of particles comprising an object of interest, which is routinely measured in scattering experiments to quantitatively characterize the structure of materials. For a polymer-like object consisting of n monomers spanning over a length scale of r, F(q) scales with the wavenumber [Formula: see text] as [Formula: see text] at an intermediate range of q, where [Formula: see text] is the fractal dimension or the inverse scaling exponent ([Formula: see text]) characterizing the geometrical feature ([Formula: see text]) of the object. F(q) can be used to describe a neuron morphology in terms of its size ([Formula: see text]) and the extent of branching quantified by [Formula: see text]. By defining the distance between F(q)s as a measure of similarity between two neuronal morphologies, we tackle the neuron classification problem. In comparison with other existing classification methods for neuronal morphologies, our F(q)-based classification rests solely on 3D coordinates of neurons with no prior knowledge of morphological features. When applied to publicly available neuron datasets from three different organisms, our method not only complements other methods but also offers a physical picture of how the dendritic and axonal branches of an individual neuron fill the space of dense neural networks inside the brain.
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Affiliation(s)
- Kiri Choi
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, 02455, Korea
| | - Won Kyu Kim
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, 02455, Korea
| | - Changbong Hyeon
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, 02455, Korea.
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12
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Suzuki N, Zou Y, Sun H, Eichel K, Shao M, Shih M, Shen K, Chang C. Two intrinsic timing mechanisms set start and end times for dendritic arborization of a nociceptive neuron. Proc Natl Acad Sci U S A 2022; 119:e2210053119. [PMID: 36322763 PMCID: PMC9659368 DOI: 10.1073/pnas.2210053119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022] Open
Abstract
Choreographic dendritic arborization takes place within a defined time frame, but the timing mechanism is currently not known. Here, we report that the precisely timed lin-4-lin-14 regulatory circuit triggers an initial dendritic growth activity, whereas the precisely timed lin-28-let-7-lin-41 regulatory circuit signals a subsequent developmental decline in dendritic growth ability, hence restricting dendritic arborization within a set time frame. Loss-of-function mutations in the lin-4 microRNA gene cause limited dendritic outgrowth, whereas loss-of-function mutations in its direct target, the lin-14 transcription factor gene, cause precocious and excessive outgrowth. In contrast, loss-of-function mutations in the let-7 microRNA gene prevent a developmental decline in dendritic growth ability, whereas loss-of-function mutations in its direct target, the lin-41 tripartite motif protein gene, cause further decline. lin-4 and let-7 regulatory circuits are expressed in the right place at the right time to set start and end times for dendritic arborization. Replacing the lin-4 upstream cis-regulatory sequence at the lin-4 locus with a late-onset let-7 upstream cis-regulatory sequence delays dendrite arborization, whereas replacing the let-7 upstream cis-regulatory sequence at the let-7 locus with an early-onset lin-4 upstream cis-regulatory sequence causes a precocious decline in dendritic growth ability. Our results indicate that the lin-4-lin-14 and the lin-28-let-7-lin-41 regulatory circuits control the timing of dendrite arborization through antagonistic regulation of the DMA-1 receptor level on dendrites. The LIN-14 transcription factor likely directly represses dma-1 gene expression through a transcriptional means, whereas the LIN-41 tripartite motif protein likely indirectly promotes dma-1 gene expression through a posttranscriptional means.
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Affiliation(s)
- Nobuko Suzuki
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
| | - Yan Zou
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - HaoSheng Sun
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233
| | - Kelsie Eichel
- HHMI, Stanford University, Stanford, CA 94305
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Meiyu Shao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Mushaine Shih
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
| | - Kang Shen
- HHMI, Stanford University, Stanford, CA 94305
- Department of Biology, Stanford University, Stanford, CA 94305
| | - Chieh Chang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607
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13
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Zhao T, Guan L, Ma X, Chen B, Ding M, Zou W. The cell cortex-localized protein CHDP-1 is required for dendritic development and transport in C. elegans neurons. PLoS Genet 2022; 18:e1010381. [PMID: 36126047 PMCID: PMC9524629 DOI: 10.1371/journal.pgen.1010381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 09/30/2022] [Accepted: 08/17/2022] [Indexed: 11/23/2022] Open
Abstract
Cortical actin, a thin layer of actin network underneath the plasma membranes, plays critical roles in numerous processes, such as cell morphogenesis and migration. Neurons often grow highly branched dendrite morphologies, which is crucial for neural circuit assembly. It is still poorly understood how cortical actin assembly is controlled in dendrites and whether it is critical for dendrite development, maintenance and function. In the present study, we find that knock-out of C. elegans chdp-1, which encodes a cell cortex-localized protein, causes dendrite formation defects in the larval stages and spontaneous dendrite degeneration in adults. Actin assembly in the dendritic growth cones is significantly reduced in the chdp-1 mutants. PVD neurons sense muscle contraction and act as proprioceptors. Loss of chdp-1 abolishes proprioception, which can be rescued by expressing CHDP-1 in the PVD neurons. In the high-ordered branches, loss of chdp-1 also severely affects the microtubule cytoskeleton assembly, intracellular organelle transport and neuropeptide secretion. Interestingly, knock-out of sax-1, which encodes an evolutionary conserved serine/threonine protein kinase, suppresses the defects mentioned above in chdp-1 mutants. Thus, our findings suggest that CHDP-1 and SAX-1 function in an opposing manner in the multi-dendritic neurons to modulate cortical actin assembly, which is critical for dendrite development, maintenance and function. Neurons often grow highly-branched cell protrusions called “dendrites” to receive signals from the environment or other neurons. Inside these cells, two types of cytoskeletons, known as the actin cytoskeleton and microtubule cytoskeleton, play essential roles during dendritic branching, growth and function. However, it is not fully understood how the dynamics of the neuronal cytoskeletons are controlled. Using the nematode C. elegans (a tiny roundworm found in the soil) as a research model, we found that CHDP-1, a protein localized on the cell cortex, plays a vital role in the formation of actin and microtubule cytoskeleton in the dendrites. Mutations in chdp-1 cause defective dendrite branching and transport of intracellular organelles. chdp-1 mutants cannot secrete neuropeptides from the PVD dendrites to module the muscle contraction. Surprisingly, mutating a gene called sax-1, which encodes a protein kinase, restores dendrite formation and organelle transport. Our findings reveal novel regulatory mechanisms for dendritic cytoskeleton assembly and intracellular transport.
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Affiliation(s)
- Ting Zhao
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China
| | - Liying Guan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xuehua Ma
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Baohui Chen
- Department of Cell Biology, and Bone Marrow Transplantation Center of the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
- Institute of Hematology, Zhejiang University & Zhejiang Engineering Laboratory for Stem Cell and Immunotherapy, Hangzhou, China
| | - Mei Ding
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- * E-mail: (MD); (WZ)
| | - Wei Zou
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China
- * E-mail: (MD); (WZ)
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14
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May the force be with you: Mechanosensitivity shapes dendrite development. Dev Cell 2022; 57:1561-1562. [PMID: 35820391 DOI: 10.1016/j.devcel.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mechanical stimuli have profound effects on the structure and function of various cells and tissues. In this issue of Developmental Cell, Tao et al. report that mechanosensory ion channels mediate the effects of cell membrane guidance cues on the morphogenesis of neuronal dendrites.
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15
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Rahman M, Ramirez‐Suarez NJ, Diaz‐Balzac CA, Bülow HE. Specific N-glycans regulate an extracellular adhesion complex during somatosensory dendrite patterning. EMBO Rep 2022; 23:e54163. [PMID: 35586945 PMCID: PMC9253746 DOI: 10.15252/embr.202154163] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 04/13/2022] [Accepted: 04/22/2022] [Indexed: 09/19/2023] Open
Abstract
N-glycans are molecularly diverse sugars borne by over 70% of proteins transiting the secretory pathway and have been implicated in protein folding, stability, and localization. Mutations in genes important for N-glycosylation result in congenital disorders of glycosylation that are often associated with intellectual disability. Here, we show that structurally distinct N-glycans regulate an extracellular protein complex involved in the patterning of somatosensory dendrites in Caenorhabditis elegans. Specifically, aman-2/Golgi alpha-mannosidase II, a conserved key enzyme in the biosynthesis of specific N-glycans, regulates the activity of the Menorin adhesion complex without obviously affecting the protein stability and localization of its components. AMAN-2 functions cell-autonomously to allow for decoration of the neuronal transmembrane receptor DMA-1/LRR-TM with the correct set of high-mannose/hybrid/paucimannose N-glycans. Moreover, distinct types of N-glycans on specific N-glycosylation sites regulate DMA-1/LRR-TM receptor function, which, together with three other extracellular proteins, forms the Menorin adhesion complex. In summary, specific N-glycan structures regulate dendrite patterning by coordinating the activity of an extracellular adhesion complex, suggesting that the molecular diversity of N-glycans can contribute to developmental specificity in the nervous system.
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Affiliation(s)
- Maisha Rahman
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Dominick P. Purpura Department of NeuroscienceAlbert Einstein College of MedicineBronxNYUSA
| | - Nelson J Ramirez‐Suarez
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Present address:
Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Carlos A Diaz‐Balzac
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Present address:
University of RochesterRochesterNYUSA
| | - Hannes E Bülow
- Department of GeneticsAlbert Einstein College of MedicineBronxNYUSA
- Dominick P. Purpura Department of NeuroscienceAlbert Einstein College of MedicineBronxNYUSA
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16
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Tao L, Coakley S, Shi R, Shen K. Dendrites use mechanosensitive channels to proofread ligand-mediated neurite extension during morphogenesis. Dev Cell 2022; 57:1615-1629.e3. [PMID: 35709764 DOI: 10.1016/j.devcel.2022.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/18/2022] [Accepted: 05/23/2022] [Indexed: 11/03/2022]
Abstract
Ligand-receptor interactions guide axon navigation and dendrite arborization. Mechanical forces also influence guidance choices. However, the nature of such mechanical stimulations, the mechanosensor identity, and how they interact with guidance receptors are unknown. Here, we demonstrate that mechanosensitive DEG/ENaC channels are required for dendritic arbor morphogenesis in Caenorhabditis elegans. Inhibition of DEG/ENaC channels causes reduced dendritic outgrowth and branching in vivo, a phenotype that is alleviated by overexpression of the mechanosensitive channels PEZO-1/Piezo or YVC1/TrpY1. DEG/ENaCs trigger local Ca2+ transients in growing dendritic filopodia via activation of L-type voltage-gated Ca2+ channels. Anchoring of filopodia by dendrite ligand-receptor complexes is required for the mechanical activation of DEG/ENaC channels. Therefore, mechanosensitive channels serve as a checkpoint for appropriate chemoaffinity by activating Ca2+ transients required for neurite growth.
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Affiliation(s)
- Li Tao
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Sean Coakley
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rebecca Shi
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA; Neurosciences IDP, Stanford University, Stanford, CA 94305, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
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17
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When is a neuron like an epithelial cell. Dev Biol 2022; 489:161-164. [DOI: 10.1016/j.ydbio.2022.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/18/2022] [Indexed: 11/30/2022]
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18
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Sheardown E, Mech AM, Petrazzini MEM, Leggieri A, Gidziela A, Hosseinian S, Sealy IM, Torres-Perez JV, Busch-Nentwich EM, Malanchini M, Brennan CH. Translational relevance of forward genetic screens in animal models for the study of psychiatric disease. Neurosci Biobehav Rev 2022; 135:104559. [PMID: 35124155 PMCID: PMC9016269 DOI: 10.1016/j.neubiorev.2022.104559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 12/10/2021] [Accepted: 02/01/2022] [Indexed: 12/16/2022]
Abstract
Psychiatric disorders represent a significant burden in our societies. Despite the convincing evidence pointing at gene and gene-environment interaction contributions, the role of genetics in the etiology of psychiatric disease is still poorly understood. Forward genetic screens in animal models have helped elucidate causal links. Here we discuss the application of mutagenesis-based forward genetic approaches in common animal model species: two invertebrates, nematodes (Caenorhabditis elegans) and fruit flies (Drosophila sp.); and two vertebrates, zebrafish (Danio rerio) and mice (Mus musculus), in relation to psychiatric disease. We also discuss the use of large scale genomic studies in human populations. Despite the advances using data from human populations, animal models coupled with next-generation sequencing strategies are still needed. Although with its own limitations, zebrafish possess characteristics that make them especially well-suited to forward genetic studies exploring the etiology of psychiatric disorders.
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Affiliation(s)
- Eva Sheardown
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Aleksandra M Mech
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | | | - Adele Leggieri
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Agnieszka Gidziela
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Saeedeh Hosseinian
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Ian M Sealy
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Department of Medicine, University of Cambridge, Cambridge, UK
| | - Jose V Torres-Perez
- UK Dementia Research Institute at Imperial College London and Department of Brain Sciences, Imperial College London, 86 Wood Lane, London W12 0BZ, UK
| | - Elisabeth M Busch-Nentwich
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Margherita Malanchini
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK
| | - Caroline H Brennan
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, England, UK.
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19
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Molecular mechanisms regulating the spatial configuration of neurites. Semin Cell Dev Biol 2022; 129:103-114. [PMID: 35248463 DOI: 10.1016/j.semcdb.2022.02.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 02/08/2023]
Abstract
Precise neural networks, composed of axons and dendrites, are the structural basis for information processing in the brain. Therefore, the correct formation of neurites is critical for accurate neural function. In particular, the three-dimensional structures of dendrites vary greatly among neuron types, and the unique shape of each dendrite is tightly linked to specific synaptic connections with innervating axons and is correlated with its information processing. Although many systems are involved in neurite formation, the developmental mechanisms that control the orientation, size, and arborization pattern of neurites definitively defines their three-dimensional structure in tissues. In this review, we summarize these regulatory mechanisms that establish proper spatial configurations of neurites, especially dendrites, in invertebrates and vertebrates.
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20
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Moseley-Alldredge M, Sheoran S, Yoo H, O’Keefe C, Richmond JE, Chen L. A role for the Erk MAPK pathway in modulating SAX-7/L1CAM-dependent locomotion in Caenorhabditis elegans. Genetics 2022; 220:iyab215. [PMID: 34849872 PMCID: PMC9097276 DOI: 10.1093/genetics/iyab215] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 11/11/2021] [Indexed: 01/13/2023] Open
Abstract
L1CAMs are immunoglobulin cell adhesion molecules that function in nervous system development and function. Besides being associated with autism and schizophrenia spectrum disorders, impaired L1CAM function also underlies the X-linked L1 syndrome, which encompasses a group of neurological conditions, including spastic paraplegia and congenital hydrocephalus. Studies on vertebrate and invertebrate L1CAMs established conserved roles that include axon guidance, dendrite morphogenesis, synapse development, and maintenance of neural architecture. We previously identified a genetic interaction between the Caenorhabditis elegans L1CAM encoded by the sax-7 gene and RAB-3, a GTPase that functions in synaptic neurotransmission; rab-3; sax-7 mutant animals exhibit synthetic locomotion abnormalities and neuronal dysfunction. Here, we show that this synergism also occurs when loss of SAX-7 is combined with mutants of other genes encoding key players of the synaptic vesicle (SV) cycle. In contrast, sax-7 does not interact with genes that function in synaptogenesis. These findings suggest a postdevelopmental role for sax-7 in the regulation of synaptic activity. To assess this possibility, we conducted electrophysiological recordings and ultrastructural analyses at neuromuscular junctions; these analyses did not reveal obvious synaptic abnormalities. Lastly, based on a forward genetic screen for suppressors of the rab-3; sax-7 synthetic phenotypes, we determined that mutants in the ERK Mitogen-activated Protein Kinase (MAPK) pathway can suppress the rab-3; sax-7 locomotion defects. Moreover, we established that Erk signaling acts in a subset of cholinergic neurons in the head to promote coordinated locomotion. In combination, these results suggest a modulatory role for Erk MAPK in L1CAM-dependent locomotion in C. elegans.
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Affiliation(s)
- Melinda Moseley-Alldredge
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Seema Sheoran
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Hayoung Yoo
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Calvin O’Keefe
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Lihsia Chen
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
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21
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Shrestha BR, Burgos A, Grueber WB. The Immunoglobulin Superfamily Member Basigin Is Required for Complex Dendrite Formation in Drosophila. Front Cell Neurosci 2021; 15:739741. [PMID: 34803611 PMCID: PMC8600269 DOI: 10.3389/fncel.2021.739741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
Coordination of dendrite growth with changes in the surrounding substrate occurs widely in the nervous system and is vital for establishing and maintaining neural circuits. However, the molecular basis of this important developmental process remains poorly understood. To identify potential mediators of neuron-substrate interactions important for dendrite morphogenesis, we undertook an expression pattern-based screen in Drosophila larvae, which revealed many proteins with expression in dendritic arborization (da) sensory neurons and in neurons and their epidermal substrate. We found that reporters for Basigin, a cell surface molecule of the immunoglobulin (Ig) superfamily previously implicated in cell-cell and cell-substrate interactions, are expressed in da sensory neurons and epidermis. Loss of Basigin in da neurons led to defects in morphogenesis of the complex dendrites of class IV da neurons. Classes of sensory neurons with simpler branching patterns were unaffected by loss of Basigin. Structure-function analyses showed that a juxtamembrane KRR motif is critical for this function. Furthermore, knock down of Basigin in the epidermis led to defects in dendrite elaboration of class IV neurons, suggesting a non-autonomous role. Together, our findings support a role for Basigin in complex dendrite morphogenesis and interactions between dendrites and the adjacent epidermis.
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Affiliation(s)
- Brikha R Shrestha
- Department of Neuroscience, Columbia University Medical Center, New York, NY, United States
| | - Anita Burgos
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
| | - Wesley B Grueber
- Department of Neuroscience, Columbia University Medical Center, New York, NY, United States.,Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States.,Department of Physiology and Cellular Biophysics, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, United States
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22
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Chachar S, Chen J, Qin Y, Wu X, Yu H, Zhou Q, Fan X, Wang C, Brownell I, Xiao Y. Reciprocal signals between nerve and epithelium: how do neurons talk with epithelial cells? AMERICAN JOURNAL OF STEM CELLS 2021; 10:56-67. [PMID: 34849302 PMCID: PMC8610808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Most epithelium tissues continuously undergo self-renewal through proliferation and differentiation of epithelial stem cells (known as homeostasis), within a specialized stem cell niche. In highly innervated epithelium, peripheral nerves compose perineural niche and support stem cell homeostasis by releasing a variety of neurotransmitters, hormones, and growth factors and supplying trophic factors to the stem cells. Emerging evidence has shown that both sensory and motor nerves can regulate the fate of epithelial stem cells, thus influencing epithelium homeostasis. Understanding the mechanism of crosstalk between epithelial stem cells and neurons will reveal the important role of the perineural niche in physiological and pathological conditions. Herein, we review recent discoveries of the perineural niche in epithelium mainly in tissue homeostasis, with a limited touch in wound repair and pathogenesis.
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Affiliation(s)
- Sadaruddin Chachar
- Central Lab of Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
- Department of Biotechnology, Faculty of Crop Production, Sindh Agriculture UniversityTandojam 70060, Pakistan
| | - Jing Chen
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang UniversityHangzhou 310016, Zhejiang, China
- Zhejiang University-University of Edinburgh Institute, International Campus, Zhejiang UniversityHaining 314400, Zhejiang, China
| | - Yumei Qin
- School of Food Science and Bioengineering, Zhejiang Gongshang UniversityHangzhou 310018, Zhejiang, China
| | - Xia Wu
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Haiyan Yu
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Qiang Zhou
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
| | - Xiaojiao Fan
- School of Pharmacy, Jiangsu UniversityZhenjiang, Jiangsu, China
| | - Chaochen Wang
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang UniversityHangzhou 310016, Zhejiang, China
- Zhejiang University-University of Edinburgh Institute, International Campus, Zhejiang UniversityHaining 314400, Zhejiang, China
| | - Isaac Brownell
- Dermatology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of HealthBethesda 20892, Maryland, USA
| | - Ying Xiao
- Central Lab of Biomedical Research Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang UniversityHangzhou 310020, Zhejiang, China
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23
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Rapti G. A perspective on C. elegans neurodevelopment: from early visionaries to a booming neuroscience research. J Neurogenet 2021; 34:259-272. [PMID: 33446023 DOI: 10.1080/01677063.2020.1837799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The formation of the nervous system and its striking complexity is a remarkable feat of development. C. elegans served as a unique model to dissect the molecular events in neurodevelopment, from its early visionaries to the current booming neuroscience community. Soon after being introduced as a model, C. elegans was mapped at the level of genes, cells, and synapses, providing the first metazoan with a complete cell lineage, sequenced genome, and connectome. Here, I summarize mechanisms underlying C. elegans neurodevelopment, from the generation and diversification of neural components to their navigation and connectivity. I point out recent noteworthy findings in the fields of glia biology, sex dimorphism and plasticity in neurodevelopment, highlighting how current research connects back to the pioneering studies by Brenner, Sulston and colleagues. Multifaceted investigations in model organisms, connecting genes to cell function and behavior, expand our mechanistic understanding of neurodevelopment while allowing us to formulate emerging questions for future discoveries.
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Affiliation(s)
- Georgia Rapti
- European Molecular Biology Laboratory, Unit of Developmental Biology, Heidelberg, Germany
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24
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Shi R, Kramer DA, Chen B, Shen K. A two-step actin polymerization mechanism drives dendrite branching. Neural Dev 2021; 16:3. [PMID: 34281597 PMCID: PMC8290545 DOI: 10.1186/s13064-021-00154-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 06/14/2021] [Indexed: 11/10/2022] Open
Abstract
Background Dendrite morphogenesis plays an essential role in establishing the connectivity and receptive fields of neurons during the development of the nervous system. To generate the diverse morphologies of branched dendrites, neurons use external cues and cell surface receptors to coordinate intracellular cytoskeletal organization; however, the molecular mechanisms of how this signaling forms branched dendrites are not fully understood. Methods We performed in vivo time-lapse imaging of the PVD neuron in C. elegans in several mutants of actin regulatory proteins, such as the WAVE Regulatory Complex (WRC) and UNC-34 (homolog of Enabled/Vasodilator-stimulated phosphoprotein (Ena/VASP)). We examined the direct interaction between the WRC and UNC-34 and analyzed the localization of UNC-34 in vivo using transgenic worms expressing UNC-34 fused to GFP. Results We identify a stereotyped sequence of morphological events during dendrite outgrowth in the PVD neuron in C. elegans. Specifically, local increases in width (“swellings”) give rise to filopodia to facilitate a “rapid growth and pause” mode of growth. In unc-34 mutants, filopodia fail to form but swellings are intact. In WRC mutants, dendrite growth is largely absent, resulting from a lack of both swelling and filopodia formation. We also found that UNC-34 can directly bind to the WRC. Disrupting this binding by deleting the UNC-34 EVH1 domain prevented UNC-34 from localizing to swellings and dendrite tips, resulting in a stunted dendritic arbor and reduced filopodia outgrowth. Conclusions We propose that regulators of branched and linear F-actin cooperate to establish dendritic branches. By combining our work with existing literature, we propose that the dendrite guidance receptor DMA-1 recruits the WRC, which polymerizes branched F-actin to generate “swellings” on a mother dendrite. Then, WRC recruits the actin elongation factor UNC-34/Ena/VASP to initiate growth of a new dendritic branch from the swelling, with the help of the actin-binding protein UNC-115/abLIM. Extension of existing dendrites also proceeds via swelling formation at the dendrite tip followed by UNC-34-mediated outgrowth. Following dendrite initiation and extension, the stabilization of branches by guidance receptors further recruits WRC, resulting in an iterative process to build a complex dendritic arbor. Supplementary Information The online version contains supplementary material available at 10.1186/s13064-021-00154-0.
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Affiliation(s)
- Rebecca Shi
- Department of Biology, Stanford University, Stanford, CA, 94305, USA.,Neurosciences IDP, Stanford University, Stanford, CA, 94305, USA
| | - Daniel A Kramer
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Baoyu Chen
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA, 94305, USA. .,Howard Hughes Medical Institute, Stanford University, Stanford, CA, 94305, USA.
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25
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Yuval O, Iosilevskii Y, Meledin A, Podbilewicz B, Shemesh T. Neuron tracing and quantitative analyses of dendritic architecture reveal symmetrical three-way-junctions and phenotypes of git-1 in C. elegans. PLoS Comput Biol 2021; 17:e1009185. [PMID: 34280180 PMCID: PMC8321406 DOI: 10.1371/journal.pcbi.1009185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 07/29/2021] [Accepted: 06/15/2021] [Indexed: 11/18/2022] Open
Abstract
Complex dendritic trees are a distinctive feature of neurons. Alterations to dendritic morphology are associated with developmental, behavioral and neurodegenerative changes. The highly-arborized PVD neuron of C. elegans serves as a model to study dendritic patterning; however, quantitative, objective and automated analyses of PVD morphology are missing. Here, we present a method for neuronal feature extraction, based on deep-learning and fitting algorithms. The extracted neuronal architecture is represented by a database of structural elements for abstracted analysis. We obtain excellent automatic tracing of PVD trees and uncover that dendritic junctions are unevenly distributed. Surprisingly, these junctions are three-way-symmetrical on average, while dendritic processes are arranged orthogonally. We quantify the effect of mutation in git-1, a regulator of dendritic spine formation, on PVD morphology and discover a localized reduction in junctions. Our findings shed new light on PVD architecture, demonstrating the effectiveness of our objective analyses of dendritic morphology and suggest molecular control mechanisms. Nerve cells (neurons) collect input signals via branched cellular projections called dendrites. A major aspect of the study of neurons, dating back over a century, involves the characterization of neuronal shapes and of their dendritic processes. Here, we present an algorithmic approach for detection and classification of the tree-like dendrites of the PVD neuron in C. elegans worms. A key feature of our approach is to represent dendritic trees by a set of fundamental shapes, such as junctions and linear elements. By analyzing this dataset, we discovered several novel structural features. We have found that the junctions connecting branched dendrites have a three-way-symmetry, although the dendrites are arranged in a crosshatch pattern, and that the distribution of junctions varies across distinct sub-classes of the PVD’s dendritic tree. We further quantified subtle morphological effects due to mutation in the git-1 gene, a known regulator of dendritic spines. Our findings suggest molecular mechanisms for dendritic shape regulation and may help direct new avenues of research.
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Affiliation(s)
- Omer Yuval
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- School of Computing, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, United Kingdom
| | - Yael Iosilevskii
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
| | - Anna Meledin
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
| | - Benjamin Podbilewicz
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- * E-mail: (BP); (TS)
| | - Tom Shemesh
- Faculty of Biology, Technion–Israel Institute of Technology, Haifa, Israel
- * E-mail: (BP); (TS)
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26
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Tang LTH, Trivedi M, Freund J, Salazar CJ, Rahman M, Ramirez-Suarez NJ, Lee G, Wang Y, Grant BD, Bülow HE. The CATP-8/P5A-type ATPase functions in multiple pathways during neuronal patterning. PLoS Genet 2021; 17:e1009475. [PMID: 34197450 PMCID: PMC8279360 DOI: 10.1371/journal.pgen.1009475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 07/14/2021] [Accepted: 06/10/2021] [Indexed: 11/18/2022] Open
Abstract
The assembly of neuronal circuits involves the migrations of neurons from their place of birth to their final location in the nervous system, as well as the coordinated growth and patterning of axons and dendrites. In screens for genes required for patterning of the nervous system, we identified the catp-8/P5A-ATPase as an important regulator of neural patterning. P5A-ATPases are part of the P-type ATPases, a family of proteins known to serve a conserved function as transporters of ions, lipids and polyamines in unicellular eukaryotes, plants, and humans. While the function of many P-type ATPases is relatively well understood, the function of P5A-ATPases in metazoans remained elusive. We show here, that the Caenorhabditis elegans ortholog catp-8/P5A-ATPase is required for defined aspects of nervous system development. Specifically, the catp-8/P5A-ATPase serves functions in shaping the elaborately sculpted dendritic trees of somatosensory PVD neurons. Moreover, catp-8/P5A-ATPase is required for axonal guidance and repulsion at the midline, as well as embryonic and postembryonic neuronal migrations. Interestingly, not all axons at the midline require catp-8/P5A-ATPase, although the axons run in the same fascicles and navigate the same space. Similarly, not all neuronal migrations require catp-8/P5A-ATPase. A CATP-8/P5A-ATPase reporter is localized to the ER in most, if not all, tissues and catp-8/P5A-ATPase can function both cell-autonomously and non-autonomously to regulate neuronal development. Genetic analyses establish that catp-8/P5A-ATPase can function in multiple pathways, including the Menorin pathway, previously shown to control dendritic patterning in PVD, and Wnt signaling, which functions to control neuronal migrations. Lastly, we show that catp-8/P5A-ATPase is required for localizing select transmembrane proteins necessary for dendrite morphogenesis. Collectively, our studies suggest that catp-8/P5A-ATPase serves diverse, yet specific, roles in different genetic pathways and may be involved in the regulation or localization of transmembrane and secreted proteins to specific subcellular compartments.
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Affiliation(s)
- Leo T. H. Tang
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Meera Trivedi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Jenna Freund
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Christopher J. Salazar
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Maisha Rahman
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Nelson J. Ramirez-Suarez
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Garrett Lee
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Yu Wang
- Department of Molecular Biology & Biochemistry, Rutgers Center for Lipid Research, Rutgers University, Piscataway, New Jersey, United States of America
| | - Barth D. Grant
- Department of Molecular Biology & Biochemistry, Rutgers Center for Lipid Research, Rutgers University, Piscataway, New Jersey, United States of America
| | - Hannes E. Bülow
- Department of Genetics Albert Einstein College of Medicine, Bronx, New York, United States of America
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, United States of America
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27
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Desse VE, Blanchette CR, Nadour M, Perrat P, Rivollet L, Khandekar A, Bénard CY. Neuronal post-developmentally acting SAX-7S/L1CAM can function as cleaved fragments to maintain neuronal architecture in C. elegans. Genetics 2021; 218:6296841. [PMID: 34115111 DOI: 10.1093/genetics/iyab086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 05/24/2021] [Indexed: 01/09/2023] Open
Abstract
Whereas remarkable advances have uncovered mechanisms that drive nervous system assembly, the processes responsible for the lifelong maintenance of nervous system architecture remain poorly understood. Subsequent to its establishment during embryogenesis, neuronal architecture is maintained throughout life in the face of the animal's growth, maturation processes, the addition of new neurons, body movements, and aging. The C. elegans protein SAX-7, homologous to the vertebrate L1 protein family of neural adhesion molecules, is required for maintaining the organization of neuronal ganglia and fascicles after their successful initial embryonic development. To dissect the function of sax-7 in neuronal maintenance, we generated a null allele and sax-7S-isoform-specific alleles. We find that the null sax-7(qv30) is, in some contexts, more severe than previously described mutant alleles, and that the loss of sax-7S largely phenocopies the null, consistent with sax-7S being the key isoform in neuronal maintenance. Using a sfGFP::SAX-7S knock-in, we observe sax-7S to be predominantly expressed across the nervous system, from embryogenesis to adulthood. Yet, its role in maintaining neuronal organization is ensured by post-developmentally acting SAX-7S, as larval transgenic sax-7S(+) expression alone is sufficient to profoundly rescue the null mutants' neuronal maintenance defects. Moreover, the majority of the protein SAX-7 appears to be cleaved, and we show that these cleaved SAX-7S fragments together, not individually, can fully support neuronal maintenance. These findings contribute to our understanding of the role of the conserved protein SAX-7/L1CAM in long-term neuronal maintenance, and may help decipher processes that go awry in some neurodegenerative conditions.
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Affiliation(s)
- Virginie E Desse
- Department of Biological Sciences, CERMO-FC Research Center, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
| | - Cassandra R Blanchette
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Malika Nadour
- Department of Biological Sciences, CERMO-FC Research Center, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
| | - Paola Perrat
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Lise Rivollet
- Department of Biological Sciences, CERMO-FC Research Center, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
| | - Anagha Khandekar
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Claire Y Bénard
- Department of Biological Sciences, CERMO-FC Research Center, Université du Québec à Montréal, Montréal, QC H2X 1Y4, Canada
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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28
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Yin C, Peterman E, Rasmussen JP, Parrish JZ. Transparent Touch: Insights From Model Systems on Epidermal Control of Somatosensory Innervation. Front Cell Neurosci 2021; 15:680345. [PMID: 34135734 PMCID: PMC8200473 DOI: 10.3389/fncel.2021.680345] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/28/2021] [Indexed: 12/28/2022] Open
Abstract
Somatosensory neurons (SSNs) densely innervate our largest organ, the skin, and shape our experience of the world, mediating responses to sensory stimuli including touch, pressure, and temperature. Historically, epidermal contributions to somatosensation, including roles in shaping innervation patterns and responses to sensory stimuli, have been understudied. However, recent work demonstrates that epidermal signals dictate patterns of SSN skin innervation through a variety of mechanisms including targeting afferents to the epidermis, providing instructive cues for branching morphogenesis, growth control and structural stability of neurites, and facilitating neurite-neurite interactions. Here, we focus onstudies conducted in worms (Caenorhabditis elegans), fruit flies (Drosophila melanogaster), and zebrafish (Danio rerio): prominent model systems in which anatomical and genetic analyses have defined fundamental principles by which epidermal cells govern SSN development.
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Affiliation(s)
| | | | | | - Jay Z. Parrish
- Department of Biology, University of Washington, Seattle, WA, United States
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29
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Feng Z, Zhao Y, Li T, Nie W, Yang X, Wang X, Wu J, Liao J, Zou Y. CATP-8/P5A ATPase Regulates ER Processing of the DMA-1 Receptor for Dendritic Branching. Cell Rep 2021; 32:108101. [PMID: 32905774 DOI: 10.1016/j.celrep.2020.108101] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/05/2020] [Accepted: 08/11/2020] [Indexed: 10/23/2022] Open
Abstract
Dendrite morphogenesis is essential for a neuron to establish its receptive field and is, thus, the anatomical basis for the proper functioning of the nervous system. The molecular mechanisms governing dendrite branching are not fully understood. Using the multi-dendritic PVD neuron in the nematode Caenorhabditis elegans, we identify CATP-8/P5A ATPase as a key regulator of dendrite branching that controls the translocation of the DMA-1 receptor to the endoplasmic reticulum (ER). The specific signal peptide of DMA-1 and the ATPase activity of CATP-8 are essential for this process. Our results reveal that P5A ATPase may regulate protein translocation in the ER.
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Affiliation(s)
- Zhigang Feng
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yupeng Zhao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Tingting Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Wang Nie
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiaoyan Yang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xinjian Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jianguo Wu
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Jun Liao
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Zou
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
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Ricolo D, Castro-Ribera J, Araújo SJ. Cytoskeletal players in single-cell branching morphogenesis. Dev Biol 2021; 477:22-34. [PMID: 34004181 DOI: 10.1016/j.ydbio.2021.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/25/2021] [Accepted: 05/04/2021] [Indexed: 12/22/2022]
Abstract
Branching networks are a very common feature of multicellular animals and underlie the formation and function of numerous organs including the nervous system, the respiratory system, the vasculature and many internal glands. These networks range from subcellular structures such as dendritic trees to large multicellular tissues such as the lungs. The production of branched structures by single cells, so called subcellular branching, which has been better described in neurons and in cells of the respiratory and vascular systems, involves complex cytoskeletal remodelling events. In Drosophila, tracheal system terminal cells (TCs) and nervous system dendritic arborisation (da) neurons are good model systems for these subcellular branching processes. During development, the generation of subcellular branches by single-cells is characterized by extensive remodelling of the microtubule (MT) network and actin cytoskeleton, followed by vesicular transport and membrane dynamics. In this review, we describe the current knowledge on cytoskeletal regulation of subcellular branching, based on the terminal cells of the Drosophila tracheal system, but drawing parallels with dendritic branching and vertebrate vascular subcellular branching.
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Affiliation(s)
- Delia Ricolo
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028, Barcelona, Spain; Institute of Biomedicine University of Barcelona (IBUB), Barcelona, Spain
| | - Judith Castro-Ribera
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028, Barcelona, Spain; Institute of Biomedicine University of Barcelona (IBUB), Barcelona, Spain
| | - Sofia J Araújo
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028, Barcelona, Spain; Institute of Biomedicine University of Barcelona (IBUB), Barcelona, Spain.
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31
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Hemizygous mutations in L1CAM in two unrelated male probands with childhood onset psychosis. Psychiatr Genet 2021; 30:73-82. [PMID: 32404617 DOI: 10.1097/ypg.0000000000000253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE To identify genes underlying childhood onset psychosis. METHODS Patients with onset of psychosis at age 13 or younger were identified from clinics across England, and they and their parents were exome sequenced and analysed for possible highly penetrant genetic contributors. RESULTS We report two male childhood onset psychosis patients of different ancestries carrying hemizygous very rare possibly damaging missense variants (p.Arg846His and p.Pro145Ser) in the L1CAM gene. L1CAM is an X-linked Mendelian disease gene in which both missense and loss of function variants are associated with syndromic forms of intellectual disability and developmental disorder. CONCLUSIONS This is the first study reporting a possible extension of the phenotype of L1CAM variant carriers to childhood onset psychosis. The family history and presence of other significant rare genetic variants in the patients suggest that there may be genetic interactions modulating the presentation.
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32
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Sonnenberg SB, Rauer J, Göhr C, Gorinski N, Schade SK, Abdel Galil D, Naumenko V, Zeug A, Bischoff SC, Ponimaskin E, Guseva D. The 5-HT 4 receptor interacts with adhesion molecule L1 to modulate morphogenic signaling in neurons. J Cell Sci 2021; 134:jcs.249193. [PMID: 33536244 DOI: 10.1242/jcs.249193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 01/19/2021] [Indexed: 11/20/2022] Open
Abstract
Morphological remodeling of dendritic spines is critically involved in memory formation and depends on adhesion molecules. Serotonin receptors are also implicated in this remodeling, though the underlying mechanisms remain enigmatic. Here, we uncovered a signaling pathway involving the adhesion molecule L1CAM (L1) and serotonin receptor 5-HT4 (5-HT4R, encoded by HTR4). Using Förster resonance energy transfer (FRET) imaging, we demonstrated a physical interaction between 5-HT4R and L1, and found that 5-HT4R-L1 heterodimerization facilitates mitogen-activated protein kinase activation in a Gs-dependent manner. We also found that 5-HT4R-L1-mediated signaling is involved in G13-dependent modulation of cofilin-1 activity. In hippocampal neurons in vitro, the 5-HT4R-L1 pathway triggers maturation of dendritic spines. Thus, the 5-HT4R-L1 signaling module represents a previously unknown molecular pathway regulating synaptic remodeling.
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Affiliation(s)
| | - Jonah Rauer
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Christoph Göhr
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Nataliya Gorinski
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Sophie Kristin Schade
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Dalia Abdel Galil
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Vladimir Naumenko
- Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - André Zeug
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany
| | - Stephan C Bischoff
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart 70599, Germany
| | - Evgeni Ponimaskin
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany .,Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia.,Institute of Neuroscience, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russian Federation
| | - Daria Guseva
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover 30625, Germany .,Department of Nutritional Medicine, University of Hohenheim, Stuttgart 70599, Germany
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33
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Laranjeiro R, Harinath G, Pollard AK, Gaffney CJ, Deane CS, Vanapalli SA, Etheridge T, Szewczyk NJ, Driscoll M. Spaceflight affects neuronal morphology and alters transcellular degradation of neuronal debris in adult Caenorhabditis elegans. iScience 2021; 24:102105. [PMID: 33659873 PMCID: PMC7890410 DOI: 10.1016/j.isci.2021.102105] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/17/2020] [Accepted: 01/21/2021] [Indexed: 12/21/2022] Open
Abstract
Extended space travel is a goal of government space agencies and private companies. However, spaceflight poses risks to human health, and the effects on the nervous system have to be better characterized. Here, we exploited the unique experimental advantages of the nematode Caenorhabditis elegans to explore how spaceflight affects adult neurons in vivo. We found that animals that lived 5 days of adulthood on the International Space Station exhibited hyperbranching in PVD and touch receptor neurons. We also found that, in the presence of a neuronal proteotoxic stress, spaceflight promotes a remarkable accumulation of neuronal-derived waste in the surrounding tissues, suggesting an impaired transcellular degradation of debris released from neurons. Our data reveal that spaceflight can significantly affect adult neuronal morphology and clearance of neuronal trash, highlighting the need to carefully assess the risks of long-duration spaceflight on the nervous system and to develop adequate countermeasures for safe space exploration.
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Affiliation(s)
- Ricardo Laranjeiro
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Girish Harinath
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Amelia K. Pollard
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, University of Nottingham, Medical School Royal Derby Hospital, Derby, DE22 3DT, UK
| | - Christopher J. Gaffney
- Sport and Health Sciences, University of Exeter, Exeter, EX1 2LU, UK
- Lancaster Medical School, Health Innovation One, Lancaster University, Lancaster, LA1 4AT, UK
| | - Colleen S. Deane
- Sport and Health Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | - Siva A. Vanapalli
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, USA
| | - Timothy Etheridge
- Sport and Health Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | - Nathaniel J. Szewczyk
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research and NIHR Nottingham BRC, University of Nottingham, Medical School Royal Derby Hospital, Derby, DE22 3DT, UK
- Ohio Musculoskeletal and Neurologic Institute and Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Monica Driscoll
- Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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Abstract
Neurons develop dendritic morphologies that bear cell type-specific features in dendritic field size and geometry, branch placement and density, and the types and distributions of synaptic contacts. Dendritic patterns influence the types and numbers of inputs a neuron receives, and the ways in which neural information is processed and transmitted in the circuitry. Even subtle alterations in dendritic structures can have profound consequences on neuronal function and are implicated in neurodevelopmental disorders. In this chapter, I review how growing dendrites acquire their exquisite patterns by drawing examples from diverse neuronal cell types in vertebrate and invertebrate model systems. Dendrite morphogenesis is shaped by intrinsic and extrinsic factors such as transcriptional regulators, guidance and adhesion molecules, neighboring cells and synaptic partners. I discuss molecular mechanisms that regulate dendrite morphogenesis with a focus on five aspects of dendrite patterning: (1) Dendritic cytoskeleton and cellular machineries that build the arbor; (2) Gene regulatory mechanisms; (3) Afferent cues that regulate dendritic arbor growth; (4) Space-filling strategies that optimize dendritic coverage; and (5) Molecular cues that specify dendrite wiring. Cell type-specific implementation of these patterning mechanisms produces the diversity of dendrite morphologies that wire the nervous system.
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35
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Collinet C, Lecuit T. Programmed and self-organized flow of information during morphogenesis. Nat Rev Mol Cell Biol 2021; 22:245-265. [PMID: 33483696 DOI: 10.1038/s41580-020-00318-6] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2020] [Indexed: 11/09/2022]
Abstract
How the shape of embryos and organs emerges during development is a fundamental question that has fascinated scientists for centuries. Tissue dynamics arise from a small set of cell behaviours, including shape changes, cell contact remodelling, cell migration, cell division and cell extrusion. These behaviours require control over cell mechanics, namely active stresses associated with protrusive, contractile and adhesive forces, and hydrostatic pressure, as well as material properties of cells that dictate how cells respond to active stresses. In this Review, we address how cell mechanics and the associated cell behaviours are robustly organized in space and time during tissue morphogenesis. We first outline how not only gene expression and the resulting biochemical cues, but also mechanics and geometry act as sources of morphogenetic information to ultimately define the time and length scales of the cell behaviours driving morphogenesis. Next, we present two idealized modes of how this information flows - how it is read out and translated into a biological effect - during morphogenesis. The first, akin to a programme, follows deterministic rules and is hierarchical. The second follows the principles of self-organization, which rests on statistical rules characterizing the system's composition and configuration, local interactions and feedback. We discuss the contribution of these two modes to the mechanisms of four very general classes of tissue deformation, namely tissue folding and invagination, tissue flow and extension, tissue hollowing and, finally, tissue branching. Overall, we suggest a conceptual framework for understanding morphogenetic information that encapsulates genetics and biochemistry as well as mechanics and geometry as information modules, and the interplay of deterministic and self-organized mechanisms of their deployment, thereby diverging considerably from the traditional notion that shape is fully encoded and determined by genes.
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Affiliation(s)
- Claudio Collinet
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Campus de Luminy Case 907, Marseille, France
| | - Thomas Lecuit
- Aix-Marseille Université & CNRS, IBDM - UMR7288 & Turing Centre for Living Systems, Campus de Luminy Case 907, Marseille, France. .,Collège de France, Paris, France.
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36
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Holt E, Stanton-Turcotte D, Iulianella A. Development of the Vertebrate Trunk Sensory System: Origins, Specification, Axon Guidance, and Central Connectivity. Neuroscience 2021; 458:229-243. [PMID: 33460728 DOI: 10.1016/j.neuroscience.2020.12.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/09/2020] [Accepted: 12/31/2020] [Indexed: 12/26/2022]
Abstract
Crucial to an animal's movement through their environment and to the maintenance of their homeostatic physiology is the integration of sensory information. This is achieved by axons communicating from organs, muscle spindles and skin that connect to the sensory ganglia composing the peripheral nervous system (PNS), enabling organisms to collect an ever-constant flow of sensations and relay it to the spinal cord. The sensory system carries a wide spectrum of sensory modalities - from sharp pain to cool refreshing touch - traveling from the periphery to the spinal cord via the dorsal root ganglia (DRG). This review covers the origins and development of the DRG and the cells that populate it, and focuses on how sensory connectivity to the spinal cord is achieved by the diverse developmental and molecular processes that control axon guidance in the trunk sensory system. We also describe convergences and differences in sensory neuron formation among different vertebrate species to gain insight into underlying developmental mechanisms.
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Affiliation(s)
- Emily Holt
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Danielle Stanton-Turcotte
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Angelo Iulianella
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada.
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Nechipurenko I, Lavrentyeva S, Sengupta P. GRDN-1/Girdin regulates dendrite morphogenesis and cilium position in two specialized sensory neuron types in C. elegans. Dev Biol 2021; 472:38-51. [PMID: 33460640 DOI: 10.1016/j.ydbio.2020.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
Primary cilia are located at the dendritic tips of sensory neurons and house the molecular machinery necessary for detection and transduction of sensory stimuli. The mechanisms that coordinate dendrite extension with cilium position during sensory neuron development are not well understood. Here, we show that GRDN-1, the Caenorhabditis elegans ortholog of the highly conserved scaffold and signaling protein Girdin/GIV, regulates both cilium position and dendrite extension in the postembryonic AQR and PQR gas-sensing neurons. Mutations in grdn-1 disrupt dendrite outgrowth and mislocalize cilia to the soma or proximal axonal segments in AQR, and to a lesser extent, in PQR. GRDN-1 is localized to the basal body and regulates localization of HMR-1/Cadherin to the distal AQR dendrite. However, knockdown of HMR-1 and/or loss of SAX-7/LICAM, molecules previously implicated in sensory dendrite development in C. elegans, do not alter AQR dendrite morphology or cilium position. We find that GRDN-1 localization in AQR is regulated by UNC-116/Kinesin-1, and that correspondingly, unc-116 mutants exhibit severe AQR dendrite outgrowth and cilium positioning defects. In contrast, GRDN-1 and cilium localization in PQR is modulated by LIN-44/Wnt signaling. Together, these findings identify upstream regulators of GRDN-1, and describe new cell-specific roles for this multifunctional protein in sensory neuron development.
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Affiliation(s)
- Inna Nechipurenko
- Department of Biology, Brandeis University, Waltham, MA, USA; Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA.
| | | | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA, USA.
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Palavalli A, Tizón-Escamilla N, Rupprecht JF, Lecuit T. Deterministic and Stochastic Rules of Branching Govern Dendrite Morphogenesis of Sensory Neurons. Curr Biol 2020; 31:459-472.e4. [PMID: 33212017 DOI: 10.1016/j.cub.2020.10.054] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/22/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023]
Abstract
Dendrite morphology is necessary for the correct integration of inputs that neurons receive. The branching mechanisms allowing neurons to acquire their type-specific morphology remain unclear. Classically, axon and dendrite patterns were shown to be guided by molecules, providing deterministic cues. However, the extent to which deterministic and stochastic mechanisms, based upon purely statistical bias, contribute to the emergence of dendrite shape is largely unknown. We address this issue using the Drosophila class I vpda multi-dendritic neurons. Detailed quantitative analysis of vpda dendrite morphogenesis indicates that the primary branch grows very robustly in a fixed direction, though secondary branch numbers and lengths showed fluctuations characteristic of stochastic systems. Live-tracking dendrites and computational modeling revealed how neuron shape emerges from few local statistical parameters of branch dynamics. We report key opposing aspects of how tree architecture feedbacks on the local probability of branch shrinkage. Child branches promote stabilization of parent branches, although self-repulsion promotes shrinkage. Finally, we show that self-repulsion, mediated by the adhesion molecule Dscam1, indirectly patterns the growth of secondary branches by spatially restricting their direction of stable growth perpendicular to the primary branch. Thus, the stochastic nature of secondary branch dynamics and the existence of geometric feedback emphasize the importance of self-organization in neuronal dendrite morphogenesis.
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Affiliation(s)
- Amrutha Palavalli
- Aix Marseille Université and CNRS, IBDM - UMR7288 and Turing Centre for Living Systems Campus de Luminy Case 907, Marseille 13288, France
| | - Nicolás Tizón-Escamilla
- Aix-Marseille Université, Université de Toulon, CNRS, CPT, Turing Centre for Living Systems Campus de Luminy Case 907, Marseille 13288, France
| | - Jean-François Rupprecht
- Aix-Marseille Université, Université de Toulon, CNRS, CPT, Turing Centre for Living Systems Campus de Luminy Case 907, Marseille 13288, France.
| | - Thomas Lecuit
- Aix Marseille Université and CNRS, IBDM - UMR7288 and Turing Centre for Living Systems Campus de Luminy Case 907, Marseille 13288, France; Collège de France, 11 Place Marcelin Berthelot, Paris 75005, France.
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39
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Qin Q, Zhao T, Zou W, Shen K, Wang X. An Endoplasmic Reticulum ATPase Safeguards Endoplasmic Reticulum Identity by Removing Ectopically Localized Mitochondrial Proteins. Cell Rep 2020; 33:108363. [DOI: 10.1016/j.celrep.2020.108363] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 08/05/2020] [Accepted: 10/19/2020] [Indexed: 11/29/2022] Open
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Sherry T, Handley A, Nicholas HR, Pocock R. Harmonization of L1CAM expression facilitates axon outgrowth and guidance of a motor neuron. Development 2020; 147:dev.193805. [PMID: 32994172 DOI: 10.1242/dev.193805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/18/2020] [Indexed: 12/28/2022]
Abstract
Brain development requires precise regulation of axon outgrowth, guidance and termination by multiple signaling and adhesion molecules. How the expression of these neurodevelopmental regulators is transcriptionally controlled is poorly understood. The Caenorhabditis elegans SMD motor neurons terminate axon outgrowth upon sexual maturity and partially retract their axons during early adulthood. Here we show that C-terminal binding protein 1 (CTBP-1), a transcriptional corepressor, is required for correct SMD axonal development. Loss of CTBP-1 causes multiple defects in SMD axon development: premature outgrowth, defective guidance, delayed termination and absence of retraction. CTBP-1 controls SMD axon guidance by repressing the expression of SAX-7, an L1 cell adhesion molecule (L1CAM). CTBP-1-regulated repression is crucial because deregulated SAX-7/L1CAM causes severely aberrant SMD axons. We found that axonal defects caused by deregulated SAX-7/L1CAM are dependent on a distinct L1CAM, called LAD-2, which itself plays a parallel role in SMD axon guidance. Our results reveal that harmonization of L1CAM expression controls the development and maturation of a single neuron.
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Affiliation(s)
- Tessa Sherry
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria 3800, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ava Handley
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - Hannah R Nicholas
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria 3800, Australia
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41
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Grońska-Pęski M, Schachner M, Hébert JM. L1cam curbs the differentiation of adult-born hippocampal neurons. Stem Cell Res 2020; 48:101999. [PMID: 32971459 PMCID: PMC7578921 DOI: 10.1016/j.scr.2020.101999] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 08/19/2020] [Accepted: 09/10/2020] [Indexed: 02/05/2023] Open
Abstract
L1 is an immunoglobulin domain (Ig)-containing protein essential for a wide range of neurodevelopmental processes highly conserved across species from worms to humans. L1 can act as a cell adhesion molecule by binding to other Ig-containing proteins or as a ligand for certain tyrosine kinase receptors such as FGFRs and TRKs, which are required not only during neurodevelopment but also in hippocampal neurogenesis. Yet, the role of L1 itself in adult hippocampal neurogenesis remains unaddressed. Here, we used several Cre-driver lines in mice to conditionally delete a floxed allele of L1cam at different points along the differentiation lineage of new neurons and in surrounding neurons in the adult dentate gyrus of the hippocampus. We found that L1cam deletion in stem/progenitor cells increased: 1) the differentiation of progenitors into new neurons, 2) the complexity of dendritic arbors in immature neurons, and 3) anxiety-related behavior. In addition, deletion of L1cam in neurons leads to an earlier age-related decline in hippocampal neurogenesis. These data suggest that L1 is not only important for normal nervous system development, but also for maintaining certain neural processes in adulthood.
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Affiliation(s)
- Marta Grońska-Pęski
- Departments of Neuroscience and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Melitta Schachner
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854, USA; Center for Neuroscience, Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Jean M Hébert
- Departments of Neuroscience and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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42
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Androwski RJ, Asad N, Wood JG, Hofer A, Locke S, Smith CM, Rose B, Schroeder NE. Mutually exclusive dendritic arbors in C. elegans neurons share a common architecture and convergent molecular cues. PLoS Genet 2020; 16:e1009029. [PMID: 32997655 PMCID: PMC7549815 DOI: 10.1371/journal.pgen.1009029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 10/12/2020] [Accepted: 08/05/2020] [Indexed: 12/31/2022] Open
Abstract
Stress-induced changes to the dendritic architecture of neurons have been demonstrated in numerous mammalian and invertebrate systems. Remodeling of dendrites varies tremendously among neuron types. During the stress-induced dauer stage of Caenorhabditis elegans, the IL2 neurons arborize to cover the anterior body wall. In contrast, the FLP neurons arborize to cover an identical receptive field during reproductive development. Using time-course imaging, we show that branching between these two neuron types is highly coordinated. Furthermore, we find that the IL2 and FLP arbors have a similar dendritic architecture and use an identical downstream effector complex to control branching; however, regulation of this complex differs between stress-induced IL2 branching and FLP branching during reproductive development. We demonstrate that the unfolded protein response (UPR) sensor IRE-1, required for localization of the complex in FLP branching, is dispensable for IL2 branching at standard cultivation temperatures. Exposure of ire-1 mutants to elevated temperatures results in defective IL2 branching, thereby demonstrating a previously unknown genotype by environment interaction within the UPR. We find that the FOXO homolog, DAF-16, is required cell-autonomously to control arborization during stress-induced arborization. Likewise, several aspects of the dauer formation pathway are necessary for the neuron to remodel, including the phosphatase PTEN/DAF-18 and Cytochrome P450/DAF-9. Finally, we find that the TOR associated protein, RAPTOR/DAF-15 regulates mutually exclusive branching of the IL2 and FLP dendrites. DAF-15 promotes IL2 branching during dauer and inhibits precocious FLP growth. Together, our results shed light on molecular processes that regulate stress-mediated remodeling of dendrites across neuron classes.
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Affiliation(s)
- Rebecca J. Androwski
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Nadeem Asad
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Janet G. Wood
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Allison Hofer
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Steven Locke
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Cassandra M. Smith
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Becky Rose
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Nathan E. Schroeder
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
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Jin H, Kim B. Neurite Branching Regulated by Neuronal Cell Surface Molecules in Caenorhabditis elegans. Front Neuroanat 2020; 14:59. [PMID: 32973467 PMCID: PMC7471659 DOI: 10.3389/fnana.2020.00059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 08/04/2020] [Indexed: 01/02/2023] Open
Abstract
The high synaptic density in the nervous system results from the ability of neurites to branch. Neuronal cell surface molecules play central roles during neurite branch formation. The underlying mechanisms of surface molecule activity have often been elucidated using invertebrates with simple nervous systems. Here, we review recent advances in understanding the molecular mechanisms of neurite branching in the nematode Caenorhabditis elegans. We discuss how cell surface receptor complexes link to and modulate actin dynamics to regulate dendritic and axonal branch formation. The mechanisms of neurite branching are often coupled with other neural circuit developmental processes, such as synapse formation and axon guidance, via the same cell-cell surface molecular interactions. We also cover ectopic and sex-specific neurite branching in C. elegans in an attempt to illustrate the importance of these studies in contributing to our understanding of conserved cell surface molecule regulation of neurite branch formation.
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Affiliation(s)
- HoYong Jin
- Department of Life Science, Dongguk University-Seoul, Goyang, South Korea
| | - Byunghyuk Kim
- Department of Life Science, Dongguk University-Seoul, Goyang, South Korea
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44
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ZHAO W, ZOU W. [Intrinsic and extrinsic mechanisms regulating neuronal dendrite morphogenesis]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2020; 49:90-99. [PMID: 32621417 PMCID: PMC8800678 DOI: 10.3785/j.issn.1008-9292.2020.02.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/15/2019] [Indexed: 06/11/2023]
Abstract
Neurons are the structural and functional unit of the nervous system. Precisely regulated dendrite morphogenesis is the basis of neural circuit assembly. Numerous studies have been conducted to explore the regulatory mechanisms of dendritic morphogenesis. According to their action regions, we divide them into two categories: the intrinsic and extrinsic regulators of neuronal dendritic morphogenesis. Intrinsic factors are cell type-specific transcription factors, actin polymerization or depolymerization regulators and regulators of the secretion or endocytic pathways. These intrinsic factors are produced by neuron itself and play an important role in regulating the development of dendrites. The extrinsic regulators are either secreted proteins or transmembrane domain containing cell adhesion molecules. They often form receptor-ligand pairs to mediate attractive or repulsive dendritic guidance. In this review, we summarize recent findings on the intrinsic and external molecular mechanisms of dendrite morphogenesis from multiple model organisms, including Caenorhabditis elegans, Drosophila and mice. These studies will provide a better understanding on how defective dendrite development and maintenance are associated with neurological diseases.
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45
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A Caenorhabditis elegans Model for Integrating the Functions of Neuropsychiatric Risk Genes Identifies Components Required for Normal Dendritic Morphology. G3-GENES GENOMES GENETICS 2020; 10:1617-1628. [PMID: 32132169 PMCID: PMC7202017 DOI: 10.1534/g3.119.400925] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Analysis of patient-derived DNA samples has identified hundreds of variants that are likely involved in neuropsychiatric diseases such as autism spectrum disorder (ASD) and schizophrenia (SCZ). While these studies couple behavioral phenotypes to individual genotypes, the number and diversity of candidate genes implicated in these disorders highlights the fact that the mechanistic underpinnings of these disorders are largely unknown. Here, we describe a RNAi-based screening platform that uses C. elegans to screen candidate neuropsychiatric risk genes (NRGs) for roles in controlling dendritic arborization. To benchmark this approach, we queried published lists of NRGs whose variants in ASD and SCZ are predicted to result in complete or partial loss of gene function. We found that a significant fraction (>16%) of these candidate NRGs are essential for dendritic development. Furthermore, these gene sets are enriched for dendritic arbor phenotypes (>14 fold) when compared to control RNAi datasets of over 500 human orthologs. The diversity of PVD structural abnormalities observed in these assays suggests that the functions of diverse NRGs (encoding transcription factors, chromatin remodelers, molecular chaperones and cytoskeleton-related proteins) converge to regulate neuronal morphology and that individual NRGs may play distinct roles in dendritic branching. We also demonstrate that the experimental value of this platform by providing additional insights into the molecular frameworks of candidate NRGs. Specifically, we show that ANK2/UNC-44 function is directly integrated with known regulators of dendritic arborization and suggest that altering the dosage of ARID1B/LET-526 expression during development affects neuronal morphology without diminishing aspects of cell fate specification.
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46
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Yang WK, Chien CT. Beyond being innervated: the epidermis actively shapes sensory dendritic patterning. Open Biol 2020; 9:180257. [PMID: 30914004 PMCID: PMC6451362 DOI: 10.1098/rsob.180257] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Sensing environmental cues requires well-built neuronal circuits linked to the body surface. Sensory neurons generate dendrites to innervate surface epithelium, thereby making it the largest sensory organ in the body. Previous studies have illustrated that neuronal type, physiological function and branching patterns are determined by intrinsic factors. Perhaps for effective sensation or protection, sensory dendrites bind to or are surrounded by the substrate epidermis. Recent studies have shed light on the mechanisms by which dendrites interact with their substrates. These interactions suggest that substrates can regulate dendrite guidance, arborization and degeneration. In this review, we focus on recent studies of Drosophila and Caenorhabditis elegans that demonstrate how epidermal cells can regulate dendrites in several aspects.
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Affiliation(s)
- Wei-Kang Yang
- Institute of Molecular Biology, Academia Sinica , Taipei 115 , Taiwan
| | - Cheng-Ting Chien
- Institute of Molecular Biology, Academia Sinica , Taipei 115 , Taiwan
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47
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Cebul ER, McLachlan IG, Heiman MG. Dendrites with specialized glial attachments develop by retrograde extension using SAX-7 and GRDN-1. Development 2020; 147:dev.180448. [PMID: 31988188 DOI: 10.1242/dev.180448] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 01/07/2020] [Indexed: 12/18/2022]
Abstract
Dendrites develop elaborate morphologies in concert with surrounding glia, but the molecules that coordinate dendrite and glial morphogenesis are mostly unknown. C. elegans offers a powerful model for identifying such factors. Previous work in this system examined dendrites and glia that develop within epithelia, similar to mammalian sense organs. Here, we focus on the neurons BAG and URX, which are not part of an epithelium but instead form membranous attachments to a single glial cell at the nose, reminiscent of dendrite-glia contacts in the mammalian brain. We show that these dendrites develop by retrograde extension, in which the nascent dendrite endings anchor to the presumptive nose and then extend by stretching during embryo elongation. Using forward genetic screens, we find that dendrite development requires the adhesion protein SAX-7/L1CAM and the cytoplasmic protein GRDN-1/CCDC88C to anchor dendrite endings at the nose. SAX-7 acts in neurons and glia, while GRDN-1 acts in glia to non-autonomously promote dendrite extension. Thus, this work shows how glial factors can help to shape dendrites, and identifies a novel molecular mechanism for dendrite growth by retrograde extension.
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Affiliation(s)
- Elizabeth R Cebul
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Ian G McLachlan
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Maxwell G Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
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48
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Hoyer N, Zielke P, Hu C, Petersen M, Sauter K, Scharrenberg R, Peng Y, Kim CC, Han C, Parrish JZ, Soba P. Ret and Substrate-Derived TGF-β Maverick Regulate Space-Filling Dendrite Growth in Drosophila Sensory Neurons. Cell Rep 2020; 24:2261-2272.e5. [PMID: 30157422 DOI: 10.1016/j.celrep.2018.07.092] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 06/17/2018] [Accepted: 07/27/2018] [Indexed: 12/19/2022] Open
Abstract
Dendrite morphogenesis is a highly regulated process that gives rise to stereotyped receptive fields, which are required for proper neuronal connectivity and function. Specific classes of neurons, including Drosophila class IV dendritic arborization (C4da) neurons, also feature complete space-filling growth of dendrites. In this system, we have identified the substrate-derived TGF-β ligand maverick (mav) as a developmental signal promoting space-filling growth through the neuronal Ret receptor. Both are necessary for radial spreading of C4da neuron dendrites, and Ret is required for neuronal uptake of Mav. Moreover, local changes in Mav levels result in directed dendritic growth toward regions with higher ligand availability. Our results suggest that Mav acts as a substrate-derived secreted signal promoting dendrite growth within not-yet-covered areas of the receptive field to ensure space-filling dendritic growth.
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Affiliation(s)
- Nina Hoyer
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Philip Zielke
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Chun Hu
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Meike Petersen
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Kathrin Sauter
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Robin Scharrenberg
- Research Group Neuronal Development, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Yun Peng
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | | | - Chun Han
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Peter Soba
- Research Group Neuronal Patterning and Connectivity, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.
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49
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Fam151b, the mouse homologue of C.elegans menorin gene, is essential for retinal function. Sci Rep 2020; 10:437. [PMID: 31949211 PMCID: PMC6965129 DOI: 10.1038/s41598-019-57398-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/26/2019] [Indexed: 11/08/2022] Open
Abstract
Fam151b is a mammalian homologue of the C. elegans menorin gene, which is involved in neuronal branching. The International Mouse Phenotyping Consortium (IMPC) aims to knock out every gene in the mouse and comprehensively phenotype the mutant animals. This project identified Fam151b homozygous knock-out mice as having retinal degeneration. We show they have no photoreceptor function from eye opening, as demonstrated by a lack of electroretinograph (ERG) response. Histological analysis shows that during development of the eye the correct number of cells are produced and that the layers of the retina differentiate normally. However, after eye opening at P14, Fam151b mutant eyes exhibit signs of retinal stress and rapidly lose photoreceptor cells. We have mutated the second mammalian menorin homologue, Fam151a, and homozygous mutant mice have no discernible phenotype. Sequence analysis indicates that the FAM151 proteins are members of the PLC-like phosphodiesterase superfamily. However, the substrates and function of the proteins remains unknown.
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50
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Tao L, Porto D, Li Z, Fechner S, Lee SA, Goodman MB, Xu XZS, Lu H, Shen K. Parallel Processing of Two Mechanosensory Modalities by a Single Neuron in C. elegans. Dev Cell 2019; 51:617-631.e3. [PMID: 31735664 DOI: 10.1016/j.devcel.2019.10.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 05/24/2019] [Accepted: 10/14/2019] [Indexed: 10/25/2022]
Abstract
Neurons convert synaptic or sensory inputs into cellular outputs. It is not well understood how a single neuron senses, processes multiple stimuli, and generates distinct neuronal outcomes. Here, we describe the mechanism by which the C. elegans PVD neurons sense two mechanical stimuli: external touch and proprioceptive body movement. These two stimuli are detected by distinct mechanosensitive DEG/ENaC/ASIC channels, which trigger distinct cellular outputs linked to mechanonociception and proprioception. Mechanonociception depends on DEGT-1 and activates PVD's downstream command interneurons through its axon, while proprioception depends on DEL-1, UNC-8, and MEC-10 to induce local dendritic Ca2+ increase and dendritic release of a neuropeptide NLP-12. NLP-12 directly modulates neuromuscular junction activity through the cholecystokinin receptor homolog on motor axons, setting muscle tone and movement vigor. Thus, the same neuron simultaneously uses both its axon and dendrites as output apparatus to drive distinct sensorimotor outcomes.
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Affiliation(s)
- Li Tao
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Daniel Porto
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Zhaoyu Li
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sylvia Fechner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Sol Ah Lee
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - X Z Shawn Xu
- Life Sciences Institute and Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
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