Control of G₂ Phase Duration by CDC25B Modulates the Switch from Direct to Indirect Neurogenesis in the Neocortex

Area of Science:

• Neuroscience
• Developmental Biology
• Cell Biology

Background:

• Cortical neuron production involves a balance between apical and basal progenitors.
• This balance is crucial for generating the correct number and types of neurons.
• Cellular and molecular cues regulating this equilibrium are key to understanding brain development.

Purpose of the Study:

• To investigate the role of CDC25B phosphatase in regulating progenitor cell fate during cortical development.
• To determine how CDC25B influences the balance between direct and indirect neurogenesis.
• To elucidate the mechanisms by which CDC25B affects neural progenitor production.

Main Methods:

• Analysis of CDC25B deletion in developing mouse neocortex.
• In utero electroporation and cortical slice cultures.
• Pharmacological manipulation of cell cycle phases and CDK1 activity.

Main Results:

• Deletion of CDC25B in apical progenitors leads to increased TBR1+ neuron production and decreased TBR2+ basal progenitors.
• CDC25B deletion causes a lengthening of the G2 phase of the cell cycle without altering total cell cycle length.
• CDC25B's regulation of CDK1 activity is essential for controlling basal progenitor production and is linked to G2 phase length.

Conclusions:

• CDC25B plays a critical role in regulating the balance between direct and indirect neurogenesis.
• G2 phase length is a key determinant of neural progenitor fate.
• Targeting G2 phase regulation offers a potential avenue for manipulating neural progenitor production.