Functional characterization of two enhancers located downstream FOXP2

Area of Science:

• Genetics
• Neuroscience
• Molecular Biology

Background:

• Mutations in the FOXP2 gene coding region are linked to speech and language impairments.
• The precise mechanisms by which FOXP2 gene dysregulation contributes to language deficits remain unclear.
• Microdeletions downstream of FOXP2 have been associated with cognitive deficits.

Purpose of the Study:

• To investigate the functional role of downstream enhancers on FOXP2 gene expression.
• To explore the impact of enhancer deletion on FOXP2 target genes and associated genes.
• To understand the tissue-specific regulatory roles of these enhancers in neuronal development.

Main Methods:

• CRISPR-Cas9 gene editing was used to delete two downstream enhancers of the FOXP2 gene.
• FOXP2 expression levels were analyzed in the SK-N-MC neuroblastoma cell line.
• Gene expression changes were also assessed in HEK 293 cells to evaluate tissue specificity.

Main Results:

• Deletion of either enhancer significantly downregulated FOXP2 expression in SK-N-MC cells.
• Downregulation of FOXP2 was accompanied by upregulation of the adjacent MDFIC gene.
• The observed regulatory effects on FOXP2 and MDFIC were not statistically significant in HEK 293 cells, suggesting tissue-specific regulation.
• Six known FOXP2 target genes were also downregulated following enhancer deletion.

Conclusions:

• These findings highlight the critical role of downstream enhancers in regulating FOXP2 and MDFIC gene expression.
• The study suggests tissue-specific regulation of these genes, potentially impacting neuronal development.
• Understanding these regulatory mechanisms is crucial for deciphering the genetic underpinnings of cognition, speech, and language.