EGF-responsive neural stem cells are a transient population in the developing mouse spinal cord

Authors

  • Alfonso Represa,

    Search for more papers by this author
    • *

      Present address: INMED-INSERM U29, 163 Route de Luminy BP13, 13273 Marseille cedex 09, France

  • Takuya Shimazaki,

    Search for more papers by this author
    • **

      Present address: Division of Neuroanatomy, Department of Neuroscience, Biomedical Research Center, Osaka University Graduate School of Medicine, 2–2 Yamadaoka, Suita, Osaka, Japan 565–0871

  • Matthew Simmonds,

    1. Genes & Development Research Group, Department of Cell Biology and Anatomy, University of Calgary Faculty of Medicine, 3330 Hospital Drive N.W., Calgary, AB, T2N 4N1 Canada
    Search for more papers by this author
  • Samuel Weiss

    1. Genes & Development Research Group, Department of Cell Biology and Anatomy, University of Calgary Faculty of Medicine, 3330 Hospital Drive N.W., Calgary, AB, T2N 4N1 Canada
    Search for more papers by this author

: Dr Weiss, as above. E-mail: weiss@ucalgary.ca

Abstract

The adult mouse forebrain, which exhibits substantial ongoing cell genesis, contains self-renewing multipotent neural stem cells that respond to epidermal growth factor (EGF), but the adult spinal cord, which exhibits limited cell genesis, does not. Spinal cord development is a process characterized by defined periods of cell histogenesis. Thus, in the present study we asked whether EGF-responsive neural stem cells are present within the spinal cord during development. At embryonic day (E) 11, subsequent to the onset of neurogenesis, only fibroblast growth factor (FGF) receptors and FGF-2 (requiring heparan sulphate)-responsive stem cells are present in the spinal cord. Between E12 and 14, at the peak of spinal cord neurogenesis and the onset of gliogenesis, EGF receptors appear along with clonally derived highly expandable EGF-responsive neural stem cells. Following the cessation of cell histogenesis, the adult spinal cord is largely devoid of both EGF receptors and EGF-responsive stem cells. On the other hand, the FGF receptor1c subtype and multipotent FGF-2-responsive neural stem cells are present in early development and in the adult. The order of appearance of spinal cord neural stem cells and in vitro lineage analysis suggests that a more primitive FGF-2-responsive stem cell produces the EGF-responsive stem cell. These findings suggest that EGF-responsive neural stem cells appear transiently in the spinal cord, during the peak period of cell histogenesis, but are no longer present in the relatively quiescent adult structure.

Ancillary