eLife (Apr 2021)

DCC regulates astroglial development essential for telencephalic morphogenesis and corpus callosum formation

  • Laura Morcom,
  • Ilan Gobius,
  • Ashley PL Marsh,
  • Rodrigo Suárez,
  • Jonathan WC Lim,
  • Caitlin Bridges,
  • Yunan Ye,
  • Laura R Fenlon,
  • Yvrick Zagar,
  • Amelia M Douglass,
  • Amber-Lee S Donahoo,
  • Thomas Fothergill,
  • Samreen Shaikh,
  • Peter Kozulin,
  • Timothy J Edwards,
  • Helen M Cooper,
  • IRC5 Consortium,
  • Elliott H Sherr,
  • Alain Chédotal,
  • Richard J Leventer,
  • Paul J Lockhart,
  • Linda J Richards

DOI
https://doi.org/10.7554/eLife.61769
Journal volume & issue
Vol. 10

Abstract

Read online

The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). Deleted in colorectal carcinoma (DCC) and netrin 1 (NTN1) are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and guidance across it.

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