Switching on the Notochord
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Works Neuroembryology
Swarthmore College Works Biology Faculty Works Biology 1-1-2017 Neuroembryology D. Darnell Scott F. Gilbert Swarthmore College, [email protected] Follow this and additional works at: https://works.swarthmore.edu/fac-biology Part of the Biology Commons Let us know how access to these works benefits ouy Recommended Citation D. Darnell and Scott F. Gilbert. (2017). "Neuroembryology". Wiley Interdisciplinary Reviews: Developmental Biology. Volume 6, Issue 1. DOI: 10.1002/wdev.215 https://works.swarthmore.edu/fac-biology/493 This work is brought to you for free by Swarthmore College Libraries' Works. It has been accepted for inclusion in Biology Faculty Works by an authorized administrator of Works. For more information, please contact [email protected]. HHS Public Access Author manuscript Author ManuscriptAuthor Manuscript Author Wiley Interdiscip Manuscript Author Rev Dev Manuscript Author Biol. Author manuscript; available in PMC 2018 January 01. Published in final edited form as: Wiley Interdiscip Rev Dev Biol. 2017 January ; 6(1): . doi:10.1002/wdev.215. Neuroembryology Diana Darnell1 and Scott F. Gilbert2 1University of Arizona College of Medicine 2Swarthmore College and University of Helsinki Abstract How is it that some cells become neurons? And how is it that neurons become organized in the spinal cord and brain to allow us to walk and talk, to see, recall events in our lives, feel pain, keep our balance, and think? The cells that are specified to form the brain and spinal cord are originally located on the outside surface of the embryo. They loop inward to form the neural tube in a process called neurulation. -
The Genetic Basis of Mammalian Neurulation
REVIEWS THE GENETIC BASIS OF MAMMALIAN NEURULATION Andrew J. Copp*, Nicholas D. E. Greene* and Jennifer N. Murdoch‡ More than 80 mutant mouse genes disrupt neurulation and allow an in-depth analysis of the underlying developmental mechanisms. Although many of the genetic mutants have been studied in only rudimentary detail, several molecular pathways can already be identified as crucial for normal neurulation. These include the planar cell-polarity pathway, which is required for the initiation of neural tube closure, and the sonic hedgehog signalling pathway that regulates neural plate bending. Mutant mice also offer an opportunity to unravel the mechanisms by which folic acid prevents neural tube defects, and to develop new therapies for folate-resistant defects. 6 ECTODERM Neurulation is a fundamental event of embryogenesis distinct locations in the brain and spinal cord .By The outer of the three that culminates in the formation of the neural tube, contrast, the mechanisms that underlie the forma- embryonic (germ) layers that which is the precursor of the brain and spinal cord. A tion, elevation and fusion of the neural folds have gives rise to the entire central region of specialized dorsal ECTODERM, the neural plate, remained elusive. nervous system, plus other organs and embryonic develops bilateral neural folds at its junction with sur- An opportunity has now arisen for an incisive analy- structures. face (non-neural) ectoderm. These folds elevate, come sis of neurulation mechanisms using the growing battery into contact (appose) in the midline and fuse to create of genetically targeted and other mutant mouse strains NEURAL CREST the neural tube, which, thereafter, becomes covered by in which NTDs form part of the mutant phenotype7.At A migratory cell population that future epidermal ectoderm. -
Role of Notochord in Specification of Cardiac Left-Right Orientation In
DEVELOPMENTAL BIOLOGY 177, 96±103 (1996) ARTICLE NO. 0148 Role of Notochord in Speci®cation of Cardiac Left± View metadata, citation and similar papers at core.ac.uk brought to you by CORE Right Orientation in Zebra®sh and Xenopus provided by Elsevier - Publisher Connector Maria C. Danos and H. Joseph Yost1 Department of Cell Biology and Neuroanatomy, University of Minnesota, 4-135 Jackson Hall, 321 Church Street S.E., Minneapolis, Minnesota 55455 The left±right body axis is coordinately aligned with the orthogonal dorsoventral and anterioposterior body axes. The developmental mechanisms that regulate axis coordination are unknown. Here it is shown that the cardiac left±right orientation in zebra®sh (Danio rerio) is randomized in notochord-defective no tail and ¯oating head mutants. no tail (Brachyury) and ¯oating head (Xnot) encode putative transcription factors that are expressed in the organizer and notochord, structures which regulate dorsoventral and anterioposterior development in vertebrate embryos. Results from dorsal tissue extirpation and cardiac primordia explantation indicate that cardiac left±right orientation is dependent on dorsoanterior structures including the notochord and is speci®ed during neural fold stages in Xenopus laevis. Thus, the notochord coordinates the development of all three body axes in the vertebrate body plan. q 1996 Academic Press, Inc. INTRODUCTION lations early in development or by genetic mutation, re- sulting in a population frequency of approximately 50% In all vertebrates examined, left±right asymmetries are reversal of the normal left±right orientations (for review, consistently aligned with respect to the anterioposterior see Yost, 1995b). This suggests that in the absence of normal and dorsoventral axes. -
Update on the Notochord Including Its Embryology, Molecular Development, and Pathology: a Primer for the Clinician
Open Access Review Article DOI: 10.7759/cureus.1137 Update on the Notochord Including its Embryology, Molecular Development, and Pathology: A Primer for the Clinician Tushar Ramesh 1 , Sai V. Nagula 1 , Gabrielle G. Tardieu 2 , Erfanul Saker 2 , Mohammadali Shoja 3 , Marios Loukas 2 , Rod J. Oskouian 4 , R. Shane Tubbs 5 1. Neurology, University of Alabama at Birmingham 2. Department of Anatomical Sciences, St. George's University School of Medicine, Grenada, West Indies 3. Neurological Surgery, University of Alabama at Birmingham 4. Swedish Neuroscience Institute 5. Neurosurgery, Seattle Science Foundation Corresponding author: Gabrielle G. Tardieu, [email protected] Abstract The notochord is a rod-like embryological structure, which plays a vital role in the development of the vertebrate. Though embryological, remnants of this structure have been observed in the nucleus pulposus of the intervertebral discs of normal adults. Pathologically, these remnants can give rise to slow-growing and recurrent notochord-derived tumors called chordomas. Using standard search engines, the literature was reviewed regarding the anatomy, embryology, molecular development, and pathology of the human notochord. Clinicians who interpret imaging or treat patients with pathologies linked to the notochord should have a good working knowledge of its development and pathology. Categories: Genetics, Neurology, Other Keywords: notochord, nucleus pulposus, chordoma, spine, embryology, development Introduction And Background The notochord, namesake of the phylum chordata (Figure 1), plays a central role in vertebrate development. It is most prominent in the first trimester, wherein it guides the folding of the embryo and regulates the differentiation and maturation of surrounding tissues. It is a transient embryologic entity in humans, thought to be completely absent or present in minute quantities, within the nucleus pulposus of intervertebral discs in adults. -
The Dorsal Neural Tube Organizes the Dermamyotome and Induces Axial Myocytes in the Avian Embryo
Development 122, 231-241 (1996) 231 Printed in Great Britain © The Company of Biologists Limited 1996 DEV3253 The dorsal neural tube organizes the dermamyotome and induces axial myocytes in the avian embryo Martha S. Spence1, Joseph Yip2 and Carol A. Erickson1,* 1Section of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA 2Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA *Author for correspondence (e-mail: [email protected]) SUMMARY Somites, like all axial structures, display dorsoventral reported previously to induce sclerotome. Thus, we have polarity. The dorsal portion of the somite forms the der- demonstrated that in the context of the embryonic envi- mamyotome, which gives rise to the dermis and axial mus- ronment, a dorsalizing signal from the dorsal neural tube culature, whereas the ventromedial somite disperses to can compete with the diffusible ventralizing signal from the generate the sclerotome, which later comprises the notochord. vertebrae and intervertebral discs. Although the neural In contrast to dorsal neural tube, pieces of ventral neural tube and notochord are known to regulate some aspects of tube, dorsal ectoderm or neural crest cells, all of which this dorsoventral pattern, the precise tissues that initially have been postulated to control dermamyotome formation specify the dermamyotome, and later the myotome from it, or to induce myogenesis, either fail to do so or provoke only have been controversial. Indeed, dorsal and ventral neural minimal inductive responses in any of our assays. However, tube, notochord, ectoderm and neural crest cells have all complicating the issue, we find consistent with previous been proposed to influence dermamyotome formation or to studies that following ablation of the entire neural tube, regulate myocyte differentiation. -
An AOP-Based Ontology for Neural Tube Closure Caused by Disturbance in Retinoic Acid Signaling
An AOP-based Ontology for Neural Tube Closure Caused by Disturbance in Retinoic Acid Signaling Cellular behavior Authors: Yvonne C.M. Staal1, Nancy Baker2, 3 4 Lyle D. Burgoon , George Daston , For each cell type information on its behavior was 5 1 Thomas B. Knudsen , Aldert H. Piersma collected from the available literature to map molecular interactions and genetic signals. 1. RIVM: National Institute of Public Health and the Environment, Bilthoven, The Netherlands; 2. Leidos, RTP, NC, United States; Table 1: example of information on cellular behavior for neuroectoderm fusion. 3. US Army Engineer Research and Development Center, RTP, NC, United States; Cell type Behavior Signal 4. Proctor & Gamble Company, Cincinnati OH, …. …. …. …. United States; neuroectoderm fusion inhibited by BMP 5. NCCT, US EPA/ORD, RTP, NC, United States neuroectoderm fusion requires Grhl2 Contact: [email protected] neuroectoderm fusion requires correct cell polarity Retinoic acid (RA) balance and leading neuroectoderm fusion inhibited by RhoA to neural tube defects neuroectoderm fusion requires Lrp6 Retinoid signaling plays an important role in embryo- neuroectoderm fusion involves Ephrin fetal development and its disruption is teratogenic. The biology of the RA pathway, leading to defects in neuroectoderm fusion requires Grhl2 neural tube closure was the basis for the construction of an ontology for developmental toxicity. neuroectoderm fusion requires Lrp6 We are constructing an ontology from an AOP network neuroectoderm fusion requires Traf4 that incorporates feedback-loops, which can be used for risk assessment. neuroectoderm fusion requires Cdx2 Fig 1: Schematic visualization (top to bottom) of neural tube closure. BMP inhibits dorso-lateral hinge point neuroectoderm fusion requires Pax3 (DLHP) formation, whereas this is stimulated by Noggin. -
Embryology and Teratology in the Curricula of Healthcare Courses
ANATOMICAL EDUCATION Eur. J. Anat. 21 (1): 77-91 (2017) Embryology and Teratology in the Curricula of Healthcare Courses Bernard J. Moxham 1, Hana Brichova 2, Elpida Emmanouil-Nikoloussi 3, Andy R.M. Chirculescu 4 1Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, Wales, United Kingdom and Department of Anatomy, St. George’s University, St George, Grenada, 2First Faculty of Medicine, Institute of Histology and Embryology, Charles University Prague, Albertov 4, 128 01 Prague 2, Czech Republic and Second Medical Facul- ty, Institute of Histology and Embryology, Charles University Prague, V Úvalu 84, 150 00 Prague 5 , Czech Republic, 3The School of Medicine, European University Cyprus, 6 Diogenous str, 2404 Engomi, P.O.Box 22006, 1516 Nicosia, Cyprus , 4Department of Morphological Sciences, Division of Anatomy, Faculty of Medicine, C. Davila University, Bucharest, Romania SUMMARY Key words: Anatomy – Embryology – Education – Syllabus – Medical – Dental – Healthcare Significant changes are occurring worldwide in courses for healthcare studies, including medicine INTRODUCTION and dentistry. Critical evaluation of the place, tim- ing, and content of components that can be collec- Embryology is a sub-discipline of developmental tively grouped as the anatomical sciences has biology that relates to life before birth. Teratology however yet to be adequately undertaken. Surveys (τέρατος (teratos) meaning ‘monster’ or ‘marvel’) of teaching hours for embryology in US and UK relates to abnormal development and congenital medical courses clearly demonstrate that a dra- abnormalities (i.e. morphofunctional impairments). matic decline in the importance of the subject is in Embryological studies are concerned essentially progress, in terms of both a decrease in the num- with the laws and mechanisms associated with ber of hours allocated within the medical course normal development (ontogenesis) from the stage and in relation to changes in pedagogic methodol- of the ovum until parturition and the end of intra- ogies. -
NIH Public Access Author Manuscript Dev Dyn
NIH Public Access Author Manuscript Dev Dyn. Author manuscript; available in PMC 2006 November 13. NIH-PA Author ManuscriptPublished NIH-PA Author Manuscript in final edited NIH-PA Author Manuscript form as: Dev Dyn. 2004 January ; 229(1): 201±218. T-box Genes in Early Embryogenesis Chris Showell, Olav Binder, and Frank L. Conlon* Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina Abstract The T-box gene family, encoding related DNA-binding transcriptional regulators, plays an essential role in controlling many aspects of embryogenesis in a wide variety of organisms. The T-box genes exhibit diverse patterns of spatial and temporal expression in the developing embryo, and both genetic and molecular embryological studies have demonstrated their importance in regulating cell fate decisions that establish the early body plan, and in later processes underlying organogenesis. Despite these studies, little is known of either the regulation of the T-box genes or the identities of their transcriptional targets. The aim of this review is to examine the diverse yet conserved roles of several T-box genes in regulating early patterning in chordates and to discuss possible mechanisms through which this functional diversity might arise. Keywords T-box; T-domain; Brachyury; Eomesodermin; VegT; spadetail; no tail; tbx6; mesoderm; transcription INTRODUCTION Adult multicellular organisms typically contain a variety of different specialized cell types, their cooperative activity underpinning the function of the organism as a whole. The cellular diversity in the adult arises during embryogenesis, and one of the aims of modern developmental biology is to gain an understanding of the molecular mechanisms through which this process occurs. -
The Xenopus Brachyury Promoter Is Activated by FGF and Low Concentrations of Activin and Suppressed by High Concentrations of Ac
Downloaded from genesdev.cshlp.org on September 29, 2021 - Published by Cold Spring Harbor Laboratory Press The Xenopus Brachyury promoter is activated by FGF and low concentrations of activin and suppressed by high concentrations of activin and by paired-type homeodomain proteins Brancko V. Latinkic´, Muriel Umbhauer,1 Kathy A. Neal, Walter Lerchner, James C. Smith,3 and Vincent Cunliffe2 Division of Developmental Biology, National Institute for Medical Research (NIMR), The Ridgeway, London NW7 1AA, UK The mesoderm of Xenopus laevis arises through an inductive interaction in which signals from the vegetal hemisphere of the embryo act on overlying equatorial cells. One candidate for an endogenous mesoderm-inducing factor is activin, a member of the TGFb superfamily. Activin is of particular interest because it induces different mesodermal cell types in a concentration-dependent manner, suggesting that it acts as a morphogen. These concentration-dependent effects are exemplified by the response of Xbra, expression of which is induced in ectodermal tissue by low concentrations of activin but not by high concentrations. Xbra therefore offers an excellent paradigm for studying the way in which a morphogen gradient is interpreted in vertebrate embryos. In this paper we examine the trancriptional regulation of Xbra2, a pseudoallele of Xbra that shows an identical response to activin. Our results indicate that 381 bp 5* of the Xbra2 transcription start site are sufficient to confer responsiveness both to FGF and, in a concentration-dependent manner, to activin. We present evidence that the suppression of Xbra expression at high concentrations of activin is mediated by paired-type homeobox genes such as goosecoid, Mix.1, and Xotx2. -
Ectoderm: Neurulation, Neural Tube, Neural Crest
4. ECTODERM: NEURULATION, NEURAL TUBE, NEURAL CREST Dr. Taube P. Rothman P&S 12-520 [email protected] 212-305-7930 Recommended Reading: Larsen Human Embryology, 3rd Edition, pp. 85-102, 126-130 Summary: In this lecture, we will first consider the induction of the neural plate and the formation of the neural tube, the rudiment of the central nervous system (CNS). The anterior portion of the neural tube gives rise to the brain, the more caudal portion gives rise to the spinal cord. We will see how the requisite numbers of neural progenitors are generated in the CNS and when these cells become post mitotic. The molecular signals required for their survival and further development will also be discussed. We will then turn our attention to the neural crest, a transient structure that develops at the site where the neural tube and future epidermis meet. After delaminating from the neuraxis, the crest cells migrate via specific pathways to distant targets in an embryo where they express appropriate target-related phenotypes. The progressive restriction of the developmental potential of crest-derived cells will then be considered. Additional topics include formation of the fundamental subdivisions of the CNS and PNS, as well as molecular factors that regulate neural induction and regional distinctions in the nervous system. Learning Objectives: At the conclusion of the lecture you should be able to: 1. Discuss the tissue, cellular, and molecular basis for neural induction and neural tube formation. Be able to provide some examples of neural tube defects caused by perturbation of neural tube closure. -
Early Evolution of the T-Box Transcription Factor Family
Early evolution of the T-box transcription factor family Arnau Sebé-Pedrósa,b,1, Ana Ariza-Cosanoc,1, Matthew T. Weirauchd, Sven Leiningere, Ally Yangf, Guifré Torruellaa, Marcin Adamskie, Maja Adamskae, Timothy R. Hughesf, José Luis Gómez-Skarmetac,2, and Iñaki Ruiz-Trilloa,b,g,2 aInstitut de Biologia Evolutiva (Consejo Superior de Investigaciones Científicas-Universitat Pompeu Fabra), 08003 Barcelona, Spain; bDepartament de Genètica, Universitat de Barcelona, 08028 Barcelona, Spain; cCentro Andaluz de Biología del Desarrollo, Consejo Superior de Investigaciones Científicas, Universidad Pablo de Olavide-Junta de Andalucía, 41013 Sevilla, Spain; dCenter for Autoimmune Genomics and Etiology and Divisions of Rheumatology and Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229; eSars International Centre for Marine Molecular Biology, 5008 Bergen, Norway; fTerrence Donnelly Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 3E1; and gInstitució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain Edited by W. Ford Doolittle, Dalhousie University, Halifax, NS, Canada, and approved August 13, 2013 (received for review May 24, 2013) Developmental transcription factors are key players in animal and metazoan Brachyury genes and whether T-box genes are multicellularity, being members of the T-box family that are present in other unicellular lineages remained unclear. among the most important. Until recently, T-box transcription Here, we report a taxon-wide survey of T-box genes in several factors were thought to be exclusively present in metazoans. eukaryotic genomes and transcriptomes, including previously Here, we report the presence of T-box genes in several nonmeta- undescribed genomic data from several close relatives of meta- zoan lineages, including ichthyosporeans, filastereans, and fungi. -
Embryology of the Spine and Associated Congenital Abnormalities Kevin M
The Spine Journal 5 (2005) 564–576 Review Article Embryology of the spine and associated congenital abnormalities Kevin M. Kaplan, MDa,*, Jeffrey M. Spivak, MDa,b, John A. Bendo, MDa,b aNew York University-Hospital for Joint Diseases, Department of Orthopaedic Surgery, 14th Floor, 301 East 17th Street, New York, NY 10003, USA bHospital for Joint Diseases Spine Center, Department of Orthopaedic Surgery, 14th Floor, 301 East 17th Street, New York, NY 10003, USA Received 11 June 2004; accepted 18 October 2004 Abstract BACKGROUND CONTEXT: The spine is a complex and vital structure. Its function includes not only structural support of the body as a whole, but it also serves as a conduit for safe passage of the neural elements while allowing proper interaction with the brain. Anatomically, a variety of tissue types are represented in the spine. Embryologically, a detailed cascade of events must occur to result in the proper formation of both the musculoskeletal and neural elements of the spine. Alterations in these embryologic steps can result in one or more congenital abnormalities of the spine. Other body systems forming at the same time embryologically can be affected as well, resulting in associated defects in the cardiopulmonary system and the gastrointestinal and genito- urinary tracts. PURPOSE: This article is to serve as a review of the basic embryonic development of the spine. We will discuss the common congenital anomalies of the spine, including their clinical presentation, as examples of errors of this basic embryologic process. STUDY DESIGN/SETTING: Review of the current literature on the embryology of the spine and associated congenital abnormalities.