Integrative analysis of low- and high-resolution eQTL

Area of Science:

• Genomics
• Systems Biology
• Neuroscience

Background:

• Expression quantitative trait loci (eQTL) studies link genetic variation to gene expression.
• Recombinant inbred (RI) strains offer high power but low genetic resolution for eQTL analysis.
• Diverse inbred strains provide high genetic resolution but lower power for eQTL studies.

Purpose of the Study:

• To combine eQTL data from RI strains (BXD) and diverse strains (Mouse Diversity Panel, MDP) to overcome individual limitations.
• To systematically analyze the consistency and replication of eQTL between the BXD and MDP populations.
• To develop and apply a framework for fine-mapping BXD eQTL using high-resolution MDP data.

Main Methods:

• Analysis of hippocampus eQTL data from BXD and MDP mouse populations.
• Systematic comparison of eQTL identified independently in both populations.
• Assessment of fine-mapping strategies using pathway databases and real-life data.

Main Results:

• A significant fraction of eQTL were consistently replicated between the BXD and MDP populations.
• A strategy was proposed for fine-mapping BXD eQTL with MDP data.
• The Qrr1 eQTL hotspot on chromosome 1 was found to be driven by multiple central nervous system-specific genes, not single master regulators.

Conclusions:

• Combining data from different mouse strain types enhances eQTL analysis power and resolution.
• The developed framework provides a practical approach for high-resolution eQTL fine-mapping.
• The Qrr1 locus highlights complex genetic regulation of neurological traits involving multiple genes.