Sox5 controls cell cycle progression in intermediate progenitor cells during dentate gyrus development

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• The dentate gyrus (DG) exhibits prolonged postnatal development compared to other brain regions.
• Neural stem cells (NSCs) in the DG form a niche for lifelong granule neuron (GN) production.
• The cell cycle regulation of intermediate progenitor cells (IPCs) in the DG is not well understood.

Purpose of the Study:

• To investigate the role of transcription factor Sox5 in the development of Sox5-expressing IPCs within the DG.
• To explore the impact of Sox5 loss on DG neurogenesis and architecture.

Main Methods:

• Conditional knockout mouse models were used to study Sox5 function in IPCs.
• Cell proliferation, cell cycle duration, and differentiation were analyzed.
• DG morphology was assessed in Sox5-deficient and Sox5/Sox6 compound mutant mice.

Main Results:

• Conditional loss of Sox5 in embryonic development caused significant alterations in IPC proliferation and survival.
• Sox5-deficient IPCs showed a shortened S-phase duration during late postnatal and juvenile stages.
• Defects in GN differentiation and subtle DG morphological changes were observed in Sox5-defective mice.
• Combined loss of Sox5 and Sox6 resulted in more severe DG morphological disruptions than Sox5 loss alone.

Conclusions:

• Sox5 plays a critical role in regulating IPC cell cycle progression during postnatal DG development.
• Sox5, potentially in conjunction with Sox6, is essential for proper GN maturation and DG architecture.
• These findings highlight the importance of Sox family transcription factors in the intricate developmental processes of the DG.