DOCSLIB.ORG

Control of Dorsoventral Patterning of Somitic Derivatives by Notochord

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Control of Dorsoventral Patterning of Somitic Derivatives by Notochord Proc. Natl. Acad. Sci. USA Vol. 90, pp. 5242-5246, June 1993 Developmental Biology Control of dorsoventral patterning of somitic derivatives by notochord and floor plate (BEN glycoprotein/muscle differentiation/cartilage/myotome/sclerotome) OLIVIER POURQUI0*t, MONIQUE COLTEY*, MARIE-AIM1E TEILLET*, CHARLES ORDAHLt, AND NICOLE M. LE DOUARIN* *Institut d'Embryologie Cellulaire et Moleculaire du Centre National de la Recherche Scientifique et du College de France, 49 bis Avenue de la Belle Gabrielle, 94 736 Nogent sur Marne Cedex, France; and tDepartment of Anatomy, School of Medicine, University of California at San Francisco, CA 94116 Contributed by Nicole M. Le Douarin, February 22, 1993 ABSTRACT We have examined the effect of implantation between the paraxial mesoderm and the neural tube and of a supernumerary notochord or floor plate on dorsoventral examined the grafts' effects on somitic cell differentiation. somitic organization. We show that notochord and floor plate Our results indicate that the notochord and floor plate are are able to inhibit the differentiation of the dorsal somitic able to "ventralize" the somitic mesoderm, as was shown by derivatives-i.e., axial muscles and dermis-thus converting others to occur for the neural tube. This suggests a central the entire somite into cartilage, which normally arises only role for the notochord not only in the dorsoventral organi- from its ventral part. We infer from these results that the zation ofthe neural tube but also in that ofsomitic mesoderm. dorsoventral patterning of somitic derivatives is controlled by sigals provided by ventral axial structures. MATERIALS AND METHODS In the vertebrate embryo, one manifestation of anteroposte- Chicken embryos (JA 57 from Institut de Sdlection Animale, rior polarity is the segmentation of the paraxial mesoderm Lyon, France) and quail embryos were obtained from com- into somites. The somites are formed by the organization of mercial sources. Microsurgery was performed in ovo at mesenchymal cells in epithelial balls which are progressively stages ranging from 8 to 25 somites. Three series of opera- generated according to a craniocaudal gradient on both sides tions were performed. In the first series (Fig. 1, arrows a and of the neural tube. They become secondarily polarized along b), either the notochord (n > 30) or various parts ofthe neural the dorsoventral axis by their segregation into a dorsal and a tube (n > 20) were grafted into a groove made with a and microscalpel between the neural tube and the paraxial me- ventral component, designated dermomyotome sclero- soderm. The notochord was removed from the trunk of tome, respectively. The dermomyotome arises from the embryos ranging from 8 to 20 somites after incubation for 5 dorsal part of the somite (1) and differentiates into striated min with 20% pancreatin (GIBCO) in Ca2+- and Mg2+-free muscles (for the myotome) and dermis (for the dermatome). Tyrode's solution. For neural tube grafts, the truncal region The sclerotome yields the axial skeleton-i.e., the vertebrae, of the neural tube from embryos at stages 15-22 of Ham- intervertebral disks, and ribs (2). The early epithelial somites burger and Hamilton (11) was enzymatically dissociated and can also be divided into a lateral and medial moiety which the ventral zone, including the endogenous floor plate, as differ by their origin during gastrulation and by their subse- well as dorsal and lateral portions were cut out using Pascheff quent fate (3, 4). scissors or microscalpels. Grafts were usually performed We are interested in the role of notochord and neural tube over a length corresponding to about 10 somites at the level in the development of somites and that of neural crest of the last somites formed and of the unsegmented plate. derivatives, which are intimately associated (5, 6). The After the operation, the embryos were incubated for 1-8 notochord is an axial structure of mesodermal origin which days. For sham operations (n = 8), a cat hair or a baby hair plays a critical role in establishing the dorsoventral polarity was grafted by the same protocol. No perturbation of devel- of the neural tube (7). It induces the ventral midline of the opment was observed in these cases. In a second series of neuroepithelium to differentiate into a specialized group of experiments (Fig. 1, arrow c), embryos which received an cells, the floor plate (8, 9), which in turn acquires inductive ectopic graft of notochord were used as donors of neural properties that promote differentiation of motoneurons in the tube. The neural tube was dissociated and the region of the ventral horns (7). Notochord and floor plate are able, when neuroepithelium facing the grafted notochord, including the grafted dorsally or laterally to the neural tube in 2-day induced floor plate, was isolated and grafted as in the first chicken embryos, to induce ectopically ventral-like struc- experimental series. As a control, the ventral region of the tures-i.e., floor plate and motoneurons (7, 9). Although the neural tube, including the endogenous floor plate, was grafted role of neural tube and notochord in the development of the according to the same procedure. In the third series of axial skeleton and in cartilage induction has been thoroughly experiments (Fig. 1, arrow d), 15- to 16-somite chicken studied (10), their role in the patterning of the mesoderm is embryos were deprived of the notochord in the unsegmented poorly understood. In view of the close developmental rela- region as described (5). One day later, the operated embryos tionships between the axial structures (neural tube and no- [stages 18-19 of Hamburger and Hamilton (11)] were used as tochord) and the paraxial mesoderm in the vertebrate em- donors for grafts of the ventral part of the neural tube. Some bryo, we decided to examine how the notochord and the embryos deprived ofnotochord were fixed at different stages neural tube could act in the segregation of the different cell between embryonic day 3 (E3) and E7 as controls. lineages arising from the somites. For this purpose, we have The embryos were fixed in Carnoy's fixative, embedded in grafted the notochord or different portions of the neural tube paraffin, and serially sectioned. They were analyzed by immunocytochemistry using anti-BEN antibody to identify The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" Abbreviation: En, embryonic day n. in accordance with 18 U.S.C. §1734 solely to indicate this fact. tTo whom reprint requests should be addressed. 5242 Developmental Biology: Pourqui6 et al. Proc. Natl. Acad. Sci. USA 90 (1993) 5243 A spinal cord and the differentiation of extra motoneurons in the dorsolateral half of the neural tube. This induction of tn-N ventral structures in the neural tube was evidenced by using an anti-BEN monoclonal antibody. BEN is a glycoprotein of the immunoglobulin superfamily whose expression in the neural tube is restricted to floor-plate cells and motoneurons (12, 14). Although in many cases the induced floor plate did not express the BEN epitope, a characteristic wedging ofthe neural tube was observed (15). The influence of the graft on the unsegmented mesoderm was already detectable at E2.5 and E3. At the level of the graft, somite segmentation proceeded normally, but the dermomyotome was greatly Z uvz reduced or completely absent (Fig. 2A). This resulted later on in the absence or extreme reduction of the myotome and dermis. In embryos examined from E7 onward, it was obvious that the sclerotomal derivatives of the somites were expanded in the vicinity of the implanted notochord. Carti- B lage was much more abundant on the operated than on the contralateral side, whereas the dorsal derivatives-i.e., para- tEct vertebral muscles and dermis-were absent (Fig. 2D). When the notochord was implanted at the level of the somites that were already formed, the result was merely a disturbance of the spatial relationships between myotome and sclerotome. The myotome appeared reduced and located c Somite more laterally and ventrally than in the normal situation. In the region at the border between segmented and unsegmented mesoderm, a transition between the total absence of the dermomyotome and its displacement to a lateroventral po- Graft sition was observed. In most cases, the development oflimb, girdle, and body wall muscles was normal. Therefore, cells derived from the lateral part of the somite were not affected Unsegmented pm by the graft. Grafts of Different Portions of the Neural Tube. Implanta- tion of an additional notochord laterally to the neural tube at E2 is thus able to inhibit the differentiation of dorsal muscles Hensen's node and dermis while increasing the size of ventral somitic derivatives-i.e., cartilage. This result extends the ventral- izing activity of the notochord on the neural tube to somitic derivatives. It cannot be excluded that the latter is indirectly mediated through the neural tube. To determine whether the FIG. 1. Schematic drawing of the grafting procedure. (A) Rep- ventralizing properties of the notochord on the mesoderm resentation of the different tissues used as implants (shaded) as were shared by the floor plate, we applied the same exper- indicated by arrows: a, notochord (n); b, ventral zone (vz) of the imental paradigm to different portions of the neural tube. neural tube, including the floor plate (black area), or lateral zone (lz), or dorsal zone (dz), including the roof plate from normal embryo; c, When the floor plate was included in the graft placed induced ectopic ventral zone (ivz) including the secondary floor plate laterally to the neural tube, the effect on somite differentia- from an embryo having received a graft of notochord (n'); d, tion was similar to that produced by the notochord.
Load more

Recommended publications
  • Mutations Affecting Cell Fates and Cellular Rearrangements During Gastrulation in Zebrafish
    Development 123, 67-80 67 Printed in Great Britain © The Company of Biologists Limited 1996 DEV3335 Mutations affecting cell fates and cellular rearrangements during gastrulation in zebrafish Lilianna Solnica-Krezel†, Derek L. Stemple, Eliza Mountcastle-Shah, Zehava Rangini‡, Stephan C. F. Neuhauss, Jarema Malicki, Alexander F. Schier§, Didier Y. R. Stainier¶, Fried Zwartkruis**, Salim Abdelilah and Wolfgang Driever* Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, 13th Street, Bldg. 149, Charlestown, MA 02129, USA †Present address: Department of Molecular Biology, Vanderbilt University, Box 1820, Station B, Nashville, TN 37235, USA ‡Present address: Department of Oncology, Sharett Institute, Hadassah Hospital, Jerusalem 91120, Israel §Present address: Skirball Institute of Biomolecular Medicine, NYU Medical Center, 550 First Avenue, New York, NY 10016, USA ¶Present address: School of Medicine, Department of Biochemistry and Biophysics, UCSF, San Francisco, CA 94143-0554, USA **Present address: Laboratory for Physiological Chemistry, Utrecht University, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands *Author for correspondence (e-mail: [email protected]) SUMMARY One of the major challenges of developmental biology is mutations in these two groups identify genes necessary for understanding the inductive and morphogenetic processes the formation, maintenance or function of the dorsal that shape the vertebrate embryo. In a large-scale genetic organizer and the ventral signaling pathway, respectively. screen for zygotic effect, embryonic lethal mutations in Mutations in the third group affect primarily cellular zebrafish we have identified 25 mutations that affect spec- rearrangements during gastrulation and have complex ification of cell fates and/or cellular rearrangements during effects on cell fates in the embryo.
    [Show full text]
  • STRIP1, a Core Component of STRIPAK Complexes, Is Essential
    STRIP1, a core component of STRIPAK complexes, is PNAS PLUS essential for normal mesoderm migration in the mouse embryo Hisham Bazzia,b,c,1, Ekaterina Sorokab,c, Heather L. Alcorna, and Kathryn V. Andersona,1 aDevelopmental Biology Program, Sloan Kettering Institute, New York, NY 10065; bDepartment of Dermatology and Venereology, University Hospital of Cologne, 50937 Cologne, Germany; and cCologne Cluster of Excellence in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany Edited by Brigid L. M. Hogan, Duke University Medical Center, Durham, NC, and approved November 10, 2017 (received for review August 1, 2017) Regulated mesoderm migration is necessary for the proper mor- E-cadherin is essential for mesoderm migration (9, 10). In the phogenesis and organ formation during embryonic development. chick, directional migration of the nascent mesoderm appears Cell migration and its dependence on the cytoskeleton and signaling to depend on chemorepulsion by FGF and Wnt3a ligands expressed machines have been studied extensively in cultured cells; in at the primitive streak (11), but it is not clear whether the same contrast, remarkably little is known about the mechanisms that signals operate in the mouse. The ability of mesoderm cells to mi- regulate mesoderm cell migration in vivo. Here, we report the grate depends on a complete reorganization of the actin cytoskel- identification and characterization of a mouse mutation in striatin- eton, and motility depends on the WAVE complex and the small Strip1 interacting protein 1 ( ) that disrupts migration of the meso- GTPase RAC1 (12, 13). derm after the gastrulation epithelial-to-mesenchymal transition Experiments in cell culture recently implicated the striatin- (EMT).
    [Show full text]
  • Embryology J
    Embryology J. Matthew Velkey, Ph.D. [email protected] 452A Davison, Duke South Textbook: Langmans’s Medical Embryology, 11th ed. When possible, lectures will be recorded and there may be notes for some lectures, but still NOT a substitute for reading the text. Completing assigned reading prior to class is essential for sessions where a READINESS ASSESSMENT is scheduled. Overall goal: understand the fundamental processes by which the adult form is produced and the clinical consequences that arise from abnormal development. Follicle Maturation and Ovulation Oocytes ~2 million at birth ~40,000 at puberty ~400 ovulated over lifetime Leutinizing Hormone surge (from pituitary gland) causes changes in tissues and within follicle: • Swelling within follicle due to increased hyaluronan • Matrix metalloproteinases degrade surrounding tissue causing rupture of follicle Egg and surrounding cells (corona radiata) ejected into peritoneum Corona radiata provides bulk to facilitate capture of egg. The egg (and corona radiata) at ovulation Corona radiata Zona pellucida (ZP-1, -2, and -3) Cortical granules Transport through the oviduct At around the midpoint of the menstrual cycle (~day 14), a single egg is ovulated and swept into the oviduct. Fertilization usually occurs in the ampulla of the oviduct within 24 hrs. of ovulation. Series of cleavage and differentiation events results in the formation of a blastocyst by the 4th embryonic day. Inner cell mass generates embryonic tissues Outer trophectoderm generates placental tissues Implantation into
    [Show full text]
  • Primer the Node of the Mouse Embryo
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Magazine R617 another. Cells derived from the Figure 1 Primer transplanted node form an elongated mesodermal structure, reminiscent of the notochord, and also colonize the The node of the neural tube and the somites of the mouse embryo induced embryo. The types of tissue colonized by the graft are consistent Bruce P. Davidson and with the normal fate of the node cells in intact embryos. The notochord Patrick P.L. Tam and floor plate are known to be sources of inductive signals that About 75 years ago, Spemann and specify and pattern the neurons of Mangold discovered a specific the neural tube, the somites and the population of cells in the amphibian gut. So, during normal development, embryo that, when transplanted to the node and its derivatives appear Anterior Posterior another embryo, had the extraordinary first to specify the developmental property of inducing the formation of fates of different embryonic cell an accessory embryo complete with populations, and then to organize the head and tail structures. This seminal different tissues into a body plan. finding introduced the concept of an Current Biology embryonic organizer capable of What else does the node do? assembling the various tissue Mouse embryos that lack the components along the three activity of a forkhead domain gene, The node (or Hensen’s node, labelled by the blue colour marker of Foxa2 gene embryonic body axes, namely, anterior Foxa2, have neither a node nor a activity), is localized in the anterior region (head)–posterior (tail) (A–P), dorso notochord.
    [Show full text]
  • The Derivatives of Three-Layered Embryo (Germ Layers)
    HUMANHUMAN EMBRYOLOGYEMBRYOLOGY Department of Histology and Embryology Jilin University ChapterChapter 22 GeneralGeneral EmbryologyEmbryology FourthFourth week:week: TheThe derivativesderivatives ofof trilaminartrilaminar germgerm discdisc Dorsal side of the germ disc. At the beginning of the third week of development, the ectodermal germ layer has the shape of a disc that is broader in the cephalic than the caudal region. Cross section shows formation of trilaminar germ disc Primitive pit Drawing of a sagittal section through a 17-day embryo. The most cranial portion of the definitive notochord has formed. ectoderm Schematic view showing the definitive notochord. horizon =ectoderm hillside fields =neural plate mountain peaks =neural folds Cave sinks into mountain =neural tube valley =neural groove 7.1 Derivatives of the Ectodermal Germ Layer 1) Formation of neural tube Notochord induces the overlying ectoderm to thicken and form the neural plate. Cross section Animation of formation of neural plate When notochord is forming, primitive streak is shorten. At meanwhile, neural plate is induced to form cephalic to caudal end, following formation of notochord. By the end of 3rd week, neural folds and neural groove are formed. Neural folds fuse in the midline, beginning in cervical region and Cross section proceeding cranially and caudally. Neural tube is formed & invade into the embryo body. A. Dorsal view of a human embryo at approximately day 22. B. Dorsal view of a human embryo at approximately day 23. The nervous system is in connection with the amniotic cavity through the cranial and caudal neuropores. Cranial/anterior neuropore Neural fold heart Neural groove endoderm caudal/posterior neuropore A.
    [Show full text]
  • STRIP1, a Core Component of STRIPAK Complexes, Is Essential
    STRIP1, a core component of STRIPAK complexes, is PNAS PLUS essential for normal mesoderm migration in the mouse embryo Hisham Bazzia,b,c,1, Ekaterina Sorokab,c, Heather L. Alcorna, and Kathryn V. Andersona,1 aDevelopmental Biology Program, Sloan Kettering Institute, New York, NY 10065; bDepartment of Dermatology and Venereology, University Hospital of Cologne, 50937 Cologne, Germany; and cCologne Cluster of Excellence in Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany Edited by Brigid L. M. Hogan, Duke University Medical Center, Durham, NC, and approved November 10, 2017 (received for review August 1, 2017) Regulated mesoderm migration is necessary for the proper mor- E-cadherin is essential for mesoderm migration (9, 10). In the phogenesis and organ formation during embryonic development. chick, directional migration of the nascent mesoderm appears Cell migration and its dependence on the cytoskeleton and signaling to depend on chemorepulsion by FGF and Wnt3a ligands expressed machines have been studied extensively in cultured cells; in at the primitive streak (11), but it is not clear whether the same contrast, remarkably little is known about the mechanisms that signals operate in the mouse. The ability of mesoderm cells to mi- regulate mesoderm cell migration in vivo. Here, we report the grate depends on a complete reorganization of the actin cytoskel- identification and characterization of a mouse mutation in striatin- eton, and motility depends on the WAVE complex and the small Strip1 interacting protein 1 ( ) that disrupts migration of the meso- GTPase RAC1 (12, 13). derm after the gastrulation epithelial-to-mesenchymal transition Experiments in cell culture recently implicated the striatin- (EMT).
    [Show full text]
  • Distinct Mesoderm Migration Phenotypes in Extra-Embryonic And
    RESEARCH ARTICLE Distinct mesoderm migration phenotypes in extra-embryonic and embryonic regions of the early mouse embryo Bechara Saykali1, Navrita Mathiah1†, Wallis Nahaboo1†, Marie-Lucie Racu1, Latifa Hammou1, Matthieu Defrance2, Isabelle Migeotte1,3* 1IRIBHM, Universite´ Libre de Bruxelles, Brussels, Belgium; 2Interuniversity Institute of Bioinformatics in Brussels, Universite´ Libre de Bruxelles, Brussels, Belgium; 3Walloon Excellence in Lifesciences and Biotechnology, Wallonia, Belgium Abstract In mouse embryo gastrulation, epiblast cells delaminate at the primitive streak to form mesoderm and definitive endoderm, through an epithelial-mesenchymal transition. Mosaic expression of a membrane reporter in nascent mesoderm enabled recording cell shape and trajectory through live imaging. Upon leaving the streak, cells changed shape and extended protrusions of distinct size and abundance depending on the neighboring germ layer, as well as the region of the embryo. Embryonic trajectories were meandrous but directional, while extra- embryonic mesoderm cells showed little net displacement. Embryonic and extra-embryonic mesoderm transcriptomes highlighted distinct guidance, cytoskeleton, adhesion, and extracellular matrix signatures. Specifically, intermediate filaments were highly expressed in extra-embryonic mesoderm, while live imaging for F-actin showed abundance of actin filaments in embryonic mesoderm only. Accordingly, Rhoa or Rac1 conditional deletion in mesoderm inhibited embryonic, but not extra-embryonic mesoderm migration. Overall, this indicates separate cytoskeleton *For correspondence: regulation coordinating the morphology and migration of mesoderm subpopulations. [email protected] DOI: https://doi.org/10.7554/eLife.42434.001 †These authors contributed equally to this work Competing interests: The Introduction authors declare that no In mice, a first separation of embryonic and extra-embryonic lineages begins in the blastocyst at competing interests exist.
    [Show full text]
  • Most Neuroectoderm During Xenopus Gastrulation?
    Int. J. Dev. Biol. 46: 777-783 (2002) Original Article When does the anterior endomesderm meet the anterior- most neuroectoderm during Xenopus gastrulation? TETSUYA KOIDE1, KAZUHIKO UMESONO and CHIKARA HASHIMOTO*,2, 3 1Developmental Biology Center, University of California, Irvine, California, USA, 2Form and Function Group, PRESTO, JST, Inage-ku, Chiba, Japan and 3JT Biohistory Research Hall, Murasaki-cho, Takatsuki, Osaka, Japan ABSTRACT During amphibian gastrulation, the anterior endomesoderm is thought to move forward along the inner surface of the blastocoel roof toward the animal pole where it comes into physical contact with the anterior-most portion of the prospective head neuroectoderm (PHN), and it is also believed that this physical interaction occurs during the mid-gastrula stage. However, using Xenopus embryos we found that the interaction between the anterior endomesoderm and the PHN occurs as early as stage 10.25 and the blastocoel roof ectoderm at this stage contributed only to the epidermal tissue. We also found that once the interaction was established, these tissues continued to associate in register and ultimately became the head structures. From these findings, we propose a new model of Xenopus gastrulation. The anterior endomesoderm migrates only a short distance on the inner surface of the blastocoel roof during very early stages of gastrulation (by stage 10.25). Then, axial mesoderm formation occurs, beginning dorsally (anterior) and progressing ventrally (posterior) to complete gastrulation. This new view of Xenopus gastrulation makes it possible to directly compare vertebrate gastrulation movements. KEY WORDS: vertebrates, amphibian, gastrulation movement, leading edge mesoderm, Xenopus Introduction phase of gastrulation (Nieuwkoop and Florshutz, 1950; Vodicka and Gerhart, 1995).
    [Show full text]
  • Anterior Identity Is Established in Chick Epiblast by Hypoblast and Anterior Definitive Endoderm Susan C
    Research article 5091 Anterior identity is established in chick epiblast by hypoblast and anterior definitive endoderm Susan C. Chapman1,*, Frank R. Schubert1, Gary C. Schoenwolf2 and Andrew Lumsden1 1MRC Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guy’s Hospital, London SE1 1UL, UK 2University of Utah School of Medicine, Department of Neurobiology and Anatomy, and Children’s Health Research Center, Room 401 MREB, 20 North 1900 East, Salt Lake City, UT 84132-3401 USA *Author for correspondence (e-mail: [email protected]) Accepted 8 July 2003 Development 130, 5091-5101 © 2003 The Company of Biologists Ltd doi:10.1242/dev.00712 Summary Previous studies of head induction in the chick have failed induce Ganf, the earliest specific marker of anterior neural to demonstrate a clear role for the hypoblast and anterior plate. We demonstrate, using such RBIs (or RBIs dissected definitive endoderm (ADE) in patterning the overlying to remove the lower layer with or without tissue ectoderm, whereas data from both mouse and rabbit replacement), that the hypoblast/ADE (lower layer) is suggest patterning roles for anterior visceral endoderm required and sufficient for patterning anterior positional (AVE) and ADE. Based on similarity of gene expression identity in the overlying ectoderm, leading to expression of patterns, fate and a dual role in ‘protecting’ the prospective Ganf in neuroectoderm. Our results suggest that patterning forebrain from caudalising influences of the organiser, the of anterior positional identity and specification of neural chick hypoblast has been suggested to be the homologue of identity are separable events operating to pattern the the mouse anterior visceral endoderm.
    [Show full text]
  • Mesoderma Differenciálódása
    Differentiation of mesoderm Dr. Bódi Ildikó 2019.12.04. 36. Germ cells, fertilization, cleavage (the division of cells in the early embryo) 37. Blastulation, implantation, decidua 38. Development of the embryo shield, ectoderm, endoderm and mesoderm 2 weeks The two-layer embryo shield: epibast and hypoblast Extra-embryonic Coelom Coelom = embryonic body cavity Implantation and gastrulation Gastrulation: The blastula continues to develop, eventually forming a structure called the gastrula. (three-plate embryo shield!!) The extraembryonic mesoderm appears Gastrulation THE DEVELOPMENT OF MESODERMA, DERIVATIVES OF GERM LAYERS (Weeks 3-8 of Development) The TRILAMINAR EMBRYO – 3rd week 1. Induction from the hypolblast cells 2. Proliferation of the epiblast cells 3. Caudal forms the primitive streak with primitive node and primitive groove Heart field (in deep) NEURAL ECTODERM Endoderm 4. The proliferated epiblast cells Epidermis migrate into the 2 layers Medial region of somites Lateral region of 5. Forming the mesoderm somites Intraembrional TRILAMINAR EMBRYO: mesoderm ectoderm, mesoderm, endoderm Stem cells Extraembrional mesoderm chorda dorsalis Parts of Mesoderm Paraxialis mesoderm - somita Intermedier mesoderm gononephrotom Parietalis mesoderm somatopleura splanchnopleura PARTS OF MESODERM AXIAL - green PARAXIAL-yellow INTERMEDIER - red LATERAL - blue •Paraxial mesoderm - somites - musculoskeletal structures •Intermediate mesoderm - urogenital (kidney and genital) •Lateral plate mesoderm - body wall, body cavities, cardiovascular and GIT structures •Paraxial mesoderm - somites - musculoskeletal structures •Intermediate mesoderm - urogenital (kidney and genital) •Lateral plate mesoderm - body wall, body cavities, cardiovascular and GIT structures Week 4Scanning electron micrograph of a cross-section of a human embryo at week 4 (stage 11). Note the mesoderm structures now present and their relative position and size within the embryo.
    [Show full text]
  • NOTO Transcription Factor Directs Human Induced Pluripotent Stem Cell-Derived Mesendoderm Progenitors to a Notochordal Fate
    cells Article NOTO Transcription Factor Directs Human Induced Pluripotent Stem Cell-Derived Mesendoderm Progenitors to a Notochordal Fate Pauline Colombier 1, Boris Halgand 1,2 , Claire Chédeville 1, Caroline Chariau 3, Valentin François-Campion 4, Stéphanie Kilens 4, Nicolas Vedrenne 1, Johann Clouet 1,5, 3,4, 1,2, 1, , Laurent David y,Jérôme Guicheux y and Anne Camus * y 1 INSERM UMR 1229, RMeS, Université de Nantes, ONIRIS, F-44042 Nantes, France; [email protected] (P.C.); [email protected] (B.H.); [email protected] (C.C.); [email protected] (N.V.); [email protected] (J.C.); [email protected] (J.G.) 2 CHU Nantes, PHU 4 OTONN, F-44042 Nantes, France 3 Nantes Université, CHU Nantes, INSERM, CNRS, SFR Santé, FED 4203, Inserm UMS 016, CNRS UMS 3556, F-44042 Nantes, France; [email protected] (C.C.); [email protected] (L.D.) 4 Nantes Université, CHU Nantes, INSERM, CRTI, UMR 1064, ITUN, F-44042 Nantes, France; valentin.francois—–[email protected] (V.F.-C.); [email protected] (S.K.) 5 CHU Nantes, Pharmacie Centrale, PHU 11, F-44042 Nantes, France * Correspondence: [email protected]; Tel.: +33-02-40-41-29-43 Co-senior author. y Received: 3 January 2020; Accepted: 19 February 2020; Published: 24 February 2020 Abstract: The founder cells of the Nucleus pulposus, the centre of the intervertebral disc, originate in the embryonic notochord. After birth, mature notochordal cells (NC) are identified as key regulators of disc homeostasis.
    [Show full text]
  • A Mesoderm-Independent Role for Nodal Signaling in Convergence & Extension Gastrulation 2 Movements 3 4 Margot L.K
    bioRxiv preprint doi: https://doi.org/10.1101/671164; this version posted June 13, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 A mesoderm-independent role for Nodal signaling in convergence & extension gastrulation 2 movements 3 4 Margot L.K. Williams* and Lilianna Solnica-Krezel 5 6 Washington University School of Medicine Department of Developmental Biology, St. Louis, MO 7 * Author for correspondence: [email protected] 8 9 ABSTRACT 10 During embryogenesis, the distinct morphogenetic cell behavior programs that shape tissues are influenced 11 both by the fate of cells and their position with respect to the embryonic axes, making embryonic patterning a 12 prerequisite for morphogenesis. These two essential processes must therefore be coordinated in space and 13 time to ensure proper development, but mechanisms by which patterning information is translated to the 14 cellular machinery that drives morphogenesis remain poorly understood. Here, we address the role of Nodal 15 morphogen signaling at the intersection of cell fate specification, patterning, and anteroposterior (AP) axis 16 extension in zebrafish gastrulae and embryonic explants. AP axis extension is impaired in Nodal-deficient 17 embryos, but it is unclear whether this defect is strictly secondary to their severe mesendoderm deficiencies or 18 also results from loss of Nodal signaling per se. We find that convergence & extension (C&E) gastrulation 19 movements and underlying mediolateral (ML) cell polarization are reduced in the neuroectoderm of Nodal- 20 deficient mutants and exacerbated by simultaneous disruption of Planar Cell Polarity (PCP) signaling, 21 demonstrating at least partially parallel functions of Nodal and PCP.
    [Show full text]