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László ZI, Lele Z. Flying under the radar: CDH2 (N-cadherin), an important hub molecule in neurodevelopmental and neurodegenerative diseases. Front Neurosci 2022; 16:972059. [PMID: 36213737 PMCID: PMC9539934 DOI: 10.3389/fnins.2022.972059] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/31/2022] [Indexed: 12/03/2022] Open
Abstract
CDH2 belongs to the classic cadherin family of Ca2+-dependent cell adhesion molecules with a meticulously described dual role in cell adhesion and β-catenin signaling. During CNS development, CDH2 is involved in a wide range of processes including maintenance of neuroepithelial integrity, neural tube closure (neurulation), confinement of radial glia progenitor cells (RGPCs) to the ventricular zone and maintaining their proliferation-differentiation balance, postmitotic neural precursor migration, axon guidance, synaptic development and maintenance. In the past few years, direct and indirect evidence linked CDH2 to various neurological diseases, and in this review, we summarize recent developments regarding CDH2 function and its involvement in pathological alterations of the CNS.
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Affiliation(s)
- Zsófia I. László
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Zsolt Lele
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- *Correspondence: Zsolt Lele,
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2
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Baldwin AT, Kim JH, Seo H, Wallingford JB. Global analysis of cell behavior and protein dynamics reveals region-specific roles for Shroom3 and N-cadherin during neural tube closure. eLife 2022; 11:e66704. [PMID: 35244026 PMCID: PMC9010020 DOI: 10.7554/elife.66704] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/18/2022] [Indexed: 11/16/2022] Open
Abstract
Failures of neural tube closure are common and serious birth defects, yet we have a poor understanding of the interaction of genetics and cell biology during neural tube closure. Additionally, mutations that cause neural tube defects (NTDs) tend to affect anterior or posterior regions of the neural tube but rarely both, indicating a regional specificity to NTD genetics. To better understand the regional specificity of cell behaviors during neural tube closure, we analyzed the dynamic localization of actin and N-cadherin via high-resolution tissue-level time-lapse microscopy during Xenopus neural tube closure. To investigate the regionality of gene function, we generated mosaic mutations in shroom3, a key regulator or neural tube closure. This new analytical approach elucidates several differences between cell behaviors during cranial/anterior and spinal/posterior neural tube closure, provides mechanistic insight into the function of shroom3, and demonstrates the ability of tissue-level imaging and analysis to generate cell biological mechanistic insights into neural tube closure.
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Affiliation(s)
- Austin T Baldwin
- Department of Molecular Biosciences, University of Texas at AustinAustinUnited States
| | - Juliana H Kim
- Department of Molecular Biosciences, University of Texas at AustinAustinUnited States
| | - Hyemin Seo
- Department of Molecular Biosciences, University of Texas at AustinAustinUnited States
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at AustinAustinUnited States
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3
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Beiriger A, Narayan S, Singh N, Prince V. Development and migration of the zebrafish rhombencephalic octavolateral efferent neurons. J Comp Neurol 2021; 529:1293-1307. [PMID: 32869305 PMCID: PMC8238524 DOI: 10.1002/cne.25021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/13/2020] [Accepted: 08/25/2020] [Indexed: 02/05/2023]
Abstract
In vertebrate animals, motor and sensory efferent neurons carry information from the central nervous system (CNS) to peripheral targets. These two types of efferent systems sometimes bear a close resemblance, sharing common segmental organization, axon pathways, and chemical messengers. Here, we focus on the development of the octavolateral efferent neurons (OENs) and their interactions with the closely-related facial branchiomotor neurons (FBMNs) in zebrafish. Using live-imaging approaches, we investigate the birth, migration, and projection patterns of OENs. We find that OENs are born in two distinct groups: a group of rostral efferent neurons (RENs) that arises in the fourth segment, or rhombomere (r4), of the hindbrain and a group of caudal efferent neurons (CENs) that arises in r5. Both RENs and CENs then migrate posteriorly through the hindbrain between 18 and 48 hrs postfertilization, alongside the r4-derived FBMNs. Like the FBMNs, migration of the r4-derived RENs depends on function of the segmental identity gene hoxb1a; unlike the FBMNs, however, both OEN populations move independently of prickle1b. Further, we investigate whether the previously described "pioneer" neuron that leads FBMN migration through the hindbrain is an r4-derived FBMN/REN or an r5-derived CEN. Our experiments verify that the pioneer is an r4-derived neuron and reaffirm its role in leading FBMN migration across the r4/5 border. In contrast, the r5-derived CENs migrate independently of the pioneer. Together, these results indicate that the mechanisms OENs use to navigate the hindbrain differ significantly from those employed by FBMNs.
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Affiliation(s)
- Anastasia Beiriger
- Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, Illinois, USA
| | - Sweta Narayan
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois, USA
| | - Noor Singh
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois, USA
| | - Victoria Prince
- Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, Illinois, USA
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois, USA
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4
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Wang M, Xu G, Tang Y, Su S, Wang Y, Zhu Z. Investigation of the Molecular Mechanisms of Antioxidant Damage and Immune Response Downregulation in Liver of Coilia nasus Under Starvation Stress. Front Endocrinol (Lausanne) 2021; 12:622315. [PMID: 33732214 PMCID: PMC7959721 DOI: 10.3389/fendo.2021.622315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/08/2021] [Indexed: 01/11/2023] Open
Abstract
Commercial fishing of estuarine tapertail anchovy (Coilia nasus), an important anadromous fish species in the Yangtze River of China, has been prohibited due to the serious damage overfishing has caused to the wild population. Research regarding the energy metabolism is important for migratory fish to ensure the continuation of their existence. In this study, we performed, for the first time, a comparative transcriptome analysis of the liver of C. nasus subjected to long-term starvation stress. The results indicated that the damaging effects involved downregulation of the antioxidant capacity and immune response. The positive response to starvation involved upregulation of the anti-allergy and anticancer capacity, which supports the function of starvation in cancer inhibition, as has also been determined for human beings. This study revealed regulatory pathways, differentially expressed genes (DEGs), and mechanisms leading to damage of the liver in C. nasus affected by starvation. This research contributes information for the further study of the energy metabolism mechanism of C. nasus and provides a theoretical reference for starvation metabolism research of other fish species and even human beings.
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Affiliation(s)
- Meiyao Wang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Aquatic Animal Genome Center of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Gangchun Xu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- *Correspondence: Gangchun Xu, ; Yongkai Tang,
| | - Yongkai Tang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Aquatic Animal Genome Center of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- *Correspondence: Gangchun Xu, ; Yongkai Tang,
| | - Shengyan Su
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
- Aquatic Animal Genome Center of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yinping Wang
- Scientific Observing and Experimental Station of Fishery Resources and Environment in the Lower Reaches of the Changjiang River, Ministry of Agriculture and Rural Affairs, Wuxi, China
| | - Zhixiang Zhu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
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5
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Ichikawa T, Stuckenholz C, Davidson LA. Non-junctional role of Cadherin3 in cell migration and contact inhibition of locomotion via domain-dependent, opposing regulation of Rac1. Sci Rep 2020; 10:17326. [PMID: 33060598 PMCID: PMC7567069 DOI: 10.1038/s41598-020-73862-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 09/07/2020] [Indexed: 11/08/2022] Open
Abstract
Classical cadherins are well-known adhesion molecules responsible for physically connecting neighboring cells and signaling this cell-cell contact. Recent studies have suggested novel signaling roles for "non-junctional" cadherins (NJCads); however, the function of cadherin signaling independent of cell-cell contacts remains unknown. In this study, mesendodermal cells and tissues from gastrula stage Xenopus laevis embryos demonstrate that deletion of extracellular domains of Cadherin3 (Cdh3; formerly C-cadherin in Xenopus) disrupts contact inhibition of locomotion. In both bulk Rac1 activity assays and spatio-temporal FRET image analysis, the extracellular and cytoplasmic Cdh3 domains disrupt NJCad signaling and regulate Rac1 activity in opposing directions. Stabilization of the cytoskeleton counteracted this regulation in single cell migration assays. Our study provides novel insights into adhesion-independent signaling by Cadherin3 and its role in regulating single and collective cell migration.
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Affiliation(s)
- Takehiko Ichikawa
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Avenue, 5059-BST3, Pittsburgh, PA, 15260, USA
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, 920-1192, Japan
| | - Carsten Stuckenholz
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Avenue, 5059-BST3, Pittsburgh, PA, 15260, USA
| | - Lance A Davidson
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Avenue, 5059-BST3, Pittsburgh, PA, 15260, USA.
- Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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6
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Knüfer A, Diana G, Walsh GS, Clarke JD, Guthrie S. Cadherins regulate nuclear topography and function of developing ocular motor circuitry. eLife 2020; 9:56725. [PMID: 33001027 PMCID: PMC7599068 DOI: 10.7554/elife.56725] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 09/30/2020] [Indexed: 12/30/2022] Open
Abstract
In the vertebrate central nervous system, groups of functionally related neurons, including cranial motor neurons of the brainstem, are frequently organised as nuclei. The molecular mechanisms governing the emergence of nuclear topography and circuit function are poorly understood. Here we investigate the role of cadherin-mediated adhesion in the development of zebrafish ocular motor (sub)nuclei. We find that developing ocular motor (sub)nuclei differentially express classical cadherins. Perturbing cadherin function in these neurons results in distinct defects in neuronal positioning, including scattering of dorsal cells and defective contralateral migration of ventral subnuclei. In addition, we show that cadherin-mediated interactions between adjacent subnuclei are critical for subnucleus position. We also find that disrupting cadherin adhesivity in dorsal oculomotor neurons impairs the larval optokinetic reflex, suggesting that neuronal clustering is important for co-ordinating circuit function. Our findings reveal that cadherins regulate distinct aspects of cranial motor neuron positioning and establish subnuclear topography and motor function.
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Affiliation(s)
- Athene Knüfer
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Giovanni Diana
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Gregory S Walsh
- Department of Biology, Virginia Commonwealth University, Richmond, United States
| | - Jonathan Dw Clarke
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Sarah Guthrie
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
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7
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Accogli A, Calabretta S, St-Onge J, Boudrahem-Addour N, Dionne-Laporte A, Joset P, Azzarello-Burri S, Rauch A, Krier J, Fieg E, Pallais JC, McConkie-Rosell A, McDonald M, Freedman SF, Rivière JB, Lafond-Lapalme J, Simpson BN, Hopkin RJ, Trimouille A, Van-Gils J, Begtrup A, McWalter K, Delphine H, Keren B, Genevieve D, Argilli E, Sherr EH, Severino M, Rouleau GA, Yam PT, Charron F, Srour M. De Novo Pathogenic Variants in N-cadherin Cause a Syndromic Neurodevelopmental Disorder with Corpus Collosum, Axon, Cardiac, Ocular, and Genital Defects. Am J Hum Genet 2019; 105:854-868. [PMID: 31585109 DOI: 10.1016/j.ajhg.2019.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/05/2019] [Indexed: 01/06/2023] Open
Abstract
Cadherins constitute a family of transmembrane proteins that mediate calcium-dependent cell-cell adhesion. The extracellular domain of cadherins consists of extracellular cadherin (EC) domains, separated by calcium binding sites. The EC interacts with other cadherin molecules in cis and in trans to mechanically hold apposing cell surfaces together. CDH2 encodes N-cadherin, whose essential roles in neural development include neuronal migration and axon pathfinding. However, CDH2 has not yet been linked to a Mendelian neurodevelopmental disorder. Here, we report de novo heterozygous pathogenic variants (seven missense, two frameshift) in CDH2 in nine individuals with a syndromic neurodevelopmental disorder characterized by global developmental delay and/or intellectual disability, variable axon pathfinding defects (corpus callosum agenesis or hypoplasia, mirror movements, Duane anomaly), and ocular, cardiac, and genital anomalies. All seven missense variants (c.1057G>A [p.Asp353Asn]; c.1789G>A [p.Asp597Asn]; c.1789G>T [p.Asp597Tyr]; c.1802A>C [p.Asn601Thr]; c.1839C>G [p.Cys613Trp]; c.1880A>G [p.Asp627Gly]; c.2027A>G [p.Tyr676Cys]) result in substitution of highly conserved residues, and six of seven cluster within EC domains 4 and 5. Four of the substitutions affect the calcium-binding site in the EC4-EC5 interdomain. We show that cells expressing these variants in the EC4-EC5 domains have a defect in cell-cell adhesion; this defect includes impaired binding in trans with N-cadherin-WT expressed on apposing cells. The two frameshift variants (c.2563_2564delCT [p.Leu855Valfs∗4]; c.2564_2567dupTGTT [p.Leu856Phefs∗5]) are predicted to lead to a truncated cytoplasmic domain. Our study demonstrates that de novo heterozygous variants in CDH2 impair the adhesive activity of N-cadherin, resulting in a multisystemic developmental disorder, that could be named ACOG syndrome (agenesis of corpus callosum, axon pathfinding, cardiac, ocular, and genital defects).
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Affiliation(s)
- Andrea Accogli
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, H4A 3J1, Montreal, QC, Canada; Medical Genetics Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genova, Italy; Dipartimento di Neuroscienze, Reabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili, Università degli Studi di Genova, 16132 Genova Italy
| | - Sara Calabretta
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada
| | - Judith St-Onge
- McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada
| | | | | | - Pascal Joset
- Institute of Medical Genetics, University of Zurich, CH-8952 Schlieren, Switzerland
| | | | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, CH-8952 Schlieren, Switzerland
| | - Joel Krier
- Brigham and Women's Hospital, Boston, MA 02115, USA
| | | | | | - Allyn McConkie-Rosell
- Division of Medical Genetics, Department of Pediatrics, Duke University, Durham, NC 27707, USA
| | - Marie McDonald
- Division of Medical Genetics, Department of Pediatrics, Duke University, Durham, NC 27707, USA
| | - Sharon F Freedman
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Joël Lafond-Lapalme
- McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada
| | - Brittany N Simpson
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Robert J Hopkin
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Aurélien Trimouille
- Centre Hospitalier Universitaire Bordeaux, Service de Génétique Médicale, 33076 Bordeaux, France; Laboratoire Maladies Rares: Génétique et Métabolisme, Inserm U1211, Université de Bordeaux, 33076 Bordeaux, France
| | - Julien Van-Gils
- Centre Hospitalier Universitaire Bordeaux, Service de Génétique Médicale, 33076 Bordeaux, France; Laboratoire Maladies Rares: Génétique et Métabolisme, Inserm U1211, Université de Bordeaux, 33076 Bordeaux, France
| | | | | | - Heron Delphine
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - David Genevieve
- Département de Genetique Médicale, Maladies Rares et Médecine Personnalisée, Centre de Référence Anomalies du Développement, Université Montpellier, Unité Inserm U1183, Centre Hospitalier Universitaire Montpellier, 34000 Montpellier, France
| | - Emanuela Argilli
- Departments of Neurology and Pediatrics, Weill Institute of Neuroscience and Institute of Human Genetics, University of California, CA 94143 San Francisco
| | - Elliott H Sherr
- Departments of Neurology and Pediatrics, Weill Institute of Neuroscience and Institute of Human Genetics, University of California, CA 94143 San Francisco
| | - Mariasavina Severino
- Istituto di Ricovero e Cura a Carattere Scientifico, Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Guy A Rouleau
- Montreal Neurological Institute, McGill University, H3A 2B4, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, H3A 2B4, Montreal, QC, Canada
| | - Patricia T Yam
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada
| | - Frédéric Charron
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada; Department of Medicine, University of Montreal, H3C 3J7, Montreal, QC, Canada; Department of Anatomy and Cell Biology, McGill University, H4A 3J1, Montreal, QC, Canada; Department of Experimental Medicine, McGill University, H4A 3J1, Montreal, QC, Canada.
| | - Myriam Srour
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, H4A 3J1, Montreal, QC, Canada; McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, H3A 2B4, Montreal, QC, Canada.
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8
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Buckley DM, Sidik A, Kar RD, Eberhart JK. Differentially sensitive neuronal subpopulations in the central nervous system and the formation of hindbrain heterotopias in ethanol-exposed zebrafish. Birth Defects Res 2019; 111:700-713. [PMID: 30793540 DOI: 10.1002/bdr2.1477] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND A cardinal feature of prenatal ethanol exposure is CNS damage, resulting in a continuum of neurological and behavioral impairments that are described by the term fetal alcohol spectrum disorders (FASD). FASDs are variable and depend on several factors, including the amount, timing, and duration of prenatal ethanol exposure. To enhance interventions for CNS dysfunction, it is necessary to identify ethanol-sensitive neuronal populations and expand the understanding of factors that modify ethanol teratogenesis. METHODS To investigate the susceptibility of different neuronal subtypes, we exposed transgenic zebrafish (Danio rerio) to several ethanol concentrations (0.25, 0.5, 1.0, 1.5, or 2.0%), at different hours post fertilization (hpf; 0, 6, or 24 hpf), for various durations (0-24, 0-48, 4-24, 6-24, 6-48,or 24-48 hpf). Following exposure, embryo survival rates were determined, and CNS neurogenesis, differentiation, and patterning were assessed. RESULTS Embryo survival rates decrease as ethanol concentrations increase and drastically decline when exposed from 0-24 hpf compared to 4-24 hpf. Abnormal tangential migration of facial motor neurons is observed in isl1:gfp embryos exposed to ethanol concentrations as low as 0.25%, and the formation of IVth ventricle heterotopias are revealed by embryos exposed to ≥1.0% ethanol. Whereas, expression of olig2:dsred and ptf1a:gfp in the cerebellum and spinal cord are largely unaffected. While levels of etv4 mRNA are overtly resistant to ethanol, we observe significant reductions in ptch2 mRNA levels. CONCLUSIONS These data show differentially sensitive CNS neuron subpopulations with susceptibility to low levels of ethanol. In addition, these data reveal the formation of ethanol-induced hindbrain heterotopias.
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Affiliation(s)
- Desire M Buckley
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Alfire Sidik
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Ranjeet D Kar
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
| | - Johann K Eberhart
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas
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9
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Gurung S, Asante E, Hummel D, Williams A, Feldman-Schultz O, Halloran MC, Sittaramane V, Chandrasekhar A. Distinct roles for the cell adhesion molecule Contactin2 in the development and function of neural circuits in zebrafish. Mech Dev 2018; 152:1-12. [PMID: 29777776 DOI: 10.1016/j.mod.2018.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/02/2018] [Accepted: 05/09/2018] [Indexed: 01/17/2023]
Abstract
Contactin2 (Cntn2)/Transient Axonal Glycoprotein 1 (Tag1), a neural cell adhesion molecule, has established roles in neuronal migration and axon fasciculation in chick and mouse. In zebrafish, antisense morpholino-based studies have indicated roles for cntn2 in the migration of facial branchiomotor (FBM) neurons, the guidance of the axons of the nucleus of the medial longitudinal fascicle (nucMLF), and the outgrowth of Rohon-Beard (RB) central axons. To study functions of Cntn2 in later stages of neuronal development, we generated cntn2 mutant zebrafish using CRISPR-Cas9. Using a null mutant allele, we detected genetic interactions between cntn2 and the planar cell polarity gene vangl2, as shown previously with cntn2 morphants, demonstrating a function for cntn2 during FBM neuron migration in a sensitized background of reduced planar cell polarity signaling. In addition, maternal-zygotic (MZ) cntn2 mutant larvae exhibited aberrant touch responses and swimming, suggestive of defects in sensorimotor circuits, consistent with studies in mice. However, the nucMLF axon convergence, FBM neuron migration, and RB outgrowth defects seen in morphants were not seen in the mutants, and we show here that they are likely off-target effects of morpholinos. However, MLF axons exhibited local defasciculation in MZcntn2 mutants, consistent with a role for Cntn2 in axon fasciculation. These data demonstrate distinct roles for zebrafish cntn2 in neuronal migration and axon fasciculation, and in the function of sensorimotor circuits.
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Affiliation(s)
- Suman Gurung
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Emilia Asante
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Devynn Hummel
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Ashley Williams
- Department of Biology, Georgia Southern University, Statesboro, GA 30458, USA
| | - Oren Feldman-Schultz
- Department of Integrative Biology, Department of Neuroscience, University of Wisconsin, Madison, WI 53706, USA
| | - Mary C Halloran
- Department of Integrative Biology, Department of Neuroscience, University of Wisconsin, Madison, WI 53706, USA
| | - Vinoth Sittaramane
- Department of Biology, Georgia Southern University, Statesboro, GA 30458, USA
| | - Anand Chandrasekhar
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
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10
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Molecular specification of facial branchial motor neurons in vertebrates. Dev Biol 2018; 436:5-13. [PMID: 29391164 DOI: 10.1016/j.ydbio.2018.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/27/2018] [Accepted: 01/28/2018] [Indexed: 02/02/2023]
Abstract
Orofacial muscles are critical for life-sustaining behaviors, such as feeding and breathing. Centuries of work by neuroanatomists and surgeons resulted in the mapping of bulbar motor neurons in the brainstem and the course of the cranial nerves that carry their axons. Despite the sophisticated understanding of the anatomy of the region, the molecular mechanisms that dictate the development and maturation of facial motor neurons remain poorly understood. This fundamental problem has been recently revisited by physiologists with novel techniques of studying the rhythmic contraction of orofacial muscles in relationship to breathing. The molecular understanding of facial motor neuron development will not only lead to the comprehension of the neural basis of facial expression but may also unlock new avenues to generate stem cell-derived replacements. This review summarizes the current understanding of molecular programs involved in facial motor neuron generation, migration, and maturation, including neural circuit assembly.
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