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

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• The interhemispheric fissure (IHF) separates forebrain hemispheres during embryogenesis.
• Radial astroglia remodel the IHF, forming a substrate for corpus callosum (CC) and hippocampal commissure (HC) axon crossing.
• Deleted in colorectal carcinoma (DCC) and netrin 1 (NTN1) are known for commissural axon guidance.

Purpose of the Study:

• To investigate the role of DCC and NTN1 in forebrain commissure formation.
• To determine if DCC and NTN1 influence astroglial development and IHF remodeling.
• To examine the impact of DCC mutations on IHF remodeling and commissure formation in humans.

Main Methods:

• Analysis of Dcc and Ntn1 knockout mouse models.
• Histological examination of brain commissures.
• Investigation of human subjects with DCC mutations.

Main Results:

• DCC and NTN1 are critical for astroglial development and IHF remodeling during CC and HC formation.
• Dcc and Ntn1 knockout mice exhibit absent CC and HC, with partial defects in other commissures.
• Human subjects with DCC mutations show disrupted IHF remodeling and CC/HC malformations.

Conclusions:

• DCC and NTN1 play a crucial role in establishing the midline substrate for dorsal commissures.
• These molecules regulate astroglial remodeling of the IHF before guiding axonal growth.
• Findings highlight a conserved mechanism for forebrain commissure development involving axon guidance molecules and glial substrates.