Control of cognition and adaptive behavior by the GLP/G9a epigenetic suppressor complex

Area of Science:

• Neuroscience
• Genetics
• Epigenetics

Background:

• The genetic underpinnings of cognition and environmental adaptation are not fully understood.
• Histone modifications play a crucial role in regulating gene expression in the brain.

Purpose of the Study:

• To investigate the role of the histone methyltransferase complex GLP/G9a in cognition and adaptive behaviors.
• To explore the region-specific functions of GLP/G9a in the adult brain.

Main Methods:

• Conditional mutagenesis in mice to create neuron-specific GLP/G9a deficiency.
• Analysis of gene expression changes in adult neurons.
• Behavioral assessments to evaluate learning, motivation, and adaptation.

Main Results:

• Postnatal, neuron-specific GLP/G9a deficiency led to derepression of non-neuronal and progenitor genes in adult neurons.
• This transcriptional alteration resulted in complex behavioral abnormalities, including impaired learning, motivation, and adaptation.
• The observed behavioral deficits resemble symptoms of human 9q34 mental retardation syndrome.

Conclusions:

• The GLP/G9a complex is critical for maintaining transcriptional homeostasis in adult neurons.
• GLP/G9a-controlled histone H3K9 dimethylation is essential for regulating brain function, cognition, and adaptive behaviors.
• Dysregulation of GLP/G9a may contribute to mental retardation in both mice and humans.