Characterization of functional human-specific regulatory elements in prefrontal cortical cells

Area of Science:

• Neuroscience
• Genomics
• Evolutionary Biology

Background:

• Human-specific cis-regulatory elements (CREs) are crucial for understanding unique gene expression patterns in the adult brain.
• The precise mechanisms by which these CREs influence human brain function and evolution are not fully understood.

Purpose of the Study:

• To investigate the role of human-specific CREs in modulating gene expression and chromatin accessibility in the adult prefrontal cortex (PFC).
• To explore the evolutionary origins and neuropsychiatric relevance of these human-specific regulatory elements.

Main Methods:

• Single-nucleus transcriptomic and genome-wide chromatin accessibility assays were performed on adult human, macaque, and mouse PFC samples.
• Analysis included identifying human-specific CREs, characterizing their genomic features, and performing genome-wide association studies (GWAS).
• Machine learning was employed to prioritize functional variants within CREs associated with neuropsychiatric disorders.

Main Results:

• Human-specific gene expression and chromatin accessibility patterns were identified in the adult PFC.
• Human-specific CREs, enriched with transposable elements like ERVK and LINE-1, were found to be central to human-biased gene expression.
• Human-gained chromatin accessibility showed significant neuropsychiatric relevance, with machine learning identifying functional variants linked to disease-risk genes.

Conclusions:

• This study reveals distinct characteristics of human-specific transcriptional regulation in the adult PFC.
• Human-specific CREs, influenced by transposable elements, play a key role in PFC evolution and are implicated in neuropsychiatric disorders.
• The findings offer critical insights into the evolutionary and pathological significance of human-specific gene regulation.