Evolution of genetic mechanisms regulating cortical neurogenesis

Area of Science:

• Evolutionary biology
• Neuroscience
• Developmental biology

Background:

• The cerebral cortex size varies significantly across amniotes, with notable expansion in primates.
• This expansion is linked to increased neuron and glial cell production during embryonic development.
• Changes in neural stem and progenitor cells' self-amplification and neuron production capacity are crucial.

Purpose of the Study:

• To overview cellular mechanisms of cortical neurogenesis in amniotes.
• To discuss genetic mechanisms, including gene regulation, driving cerebral cortex expansion evolutionarily.
• To highlight the role of gene expression changes in conserved genes.

Main Methods:

• Comparative analysis of cortical development across amniote species.
• Review of recent genetic studies on primate-specific gene evolution.
• Examination of gene regulatory elements in noncoding DNA.

Main Results:

• Cortical expansion is driven by enhanced neurogenesis, involving neural progenitor cell evolution.
• Both novel gene emergence and altered expression of conserved genes contribute to cortical evolution.
• Gene regulatory elements in noncoding DNA play a significant role in controlling gene expression.

Conclusions:

• Evolutionary increases in cerebral cortex size are underpinned by modifications in cortical neurogenesis.
• Changes in gene expression, particularly in conserved genes regulated by noncoding DNA, are key drivers.
• Understanding these mechanisms provides insight into primate brain evolution.