Slit/Robo signaling modulates the proliferation of central nervous system progenitors

Neuron. 2012 Oct 18;76(2):338-52. doi: 10.1016/j.neuron.2012.08.003. Epub 2012 Oct 17.

Abstract

Neurogenesis relies on a delicate balance between progenitor maintenance and neuronal production. Progenitors divide symmetrically to increase the pool of dividing cells. Subsequently, they divide asymmetrically to self-renew and produce new neurons or, in some brain regions, intermediate progenitor cells (IPCs). Here we report that central nervous system progenitors express Robo1 and Robo2, receptors for Slit proteins that regulate axon guidance, and that absence of these receptors or their ligands leads to loss of ventricular mitoses. Conversely, production of IPCs is enhanced in Robo1/2 and Slit1/2 mutants, suggesting that Slit/Robo signaling modulates the transition between primary and intermediate progenitors. Unexpectedly, these defects do not lead to transient overproduction of neurons, probably because supernumerary IPCs fail to detach from the ventricular lining and cycle very slowly. At the molecular level, the role of Slit/Robo in progenitor cells involves transcriptional activation of the Notch effector Hes1. These findings demonstrate that Robo signaling modulates progenitor cell dynamics in the developing brain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cadherins / metabolism
  • Cell Count
  • Cell Cycle / genetics
  • Cell Proliferation*
  • Cells, Cultured
  • Central Nervous System / cytology*
  • Central Nervous System / embryology
  • Chi-Square Distribution
  • Embryo, Mammalian
  • Gene Expression Regulation, Developmental / genetics
  • Green Fluorescent Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Intercellular Signaling Peptides and Proteins / genetics
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mutation / genetics
  • Neocortex / cytology
  • Nerve Tissue Proteins / deficiency
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurogenesis
  • Neurons / physiology
  • Receptors, Immunologic / deficiency
  • Receptors, Immunologic / metabolism*
  • Roundabout Proteins
  • Signal Transduction / genetics
  • Signal Transduction / physiology*
  • Stem Cells / physiology*
  • Transcription Factor HES-1
  • Transfection

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Cadherins
  • Hes1 protein, mouse
  • Homeodomain Proteins
  • Intercellular Signaling Peptides and Proteins
  • Nerve Tissue Proteins
  • Receptors, Immunologic
  • Robo2 protein, mouse
  • Slit1 protein, mouse
  • Transcription Factor HES-1
  • Green Fluorescent Proteins
  • Slit homolog 2 protein