The Importance of Regulatory Network Structure for Complex Trait Heritability and Evolution

Area of Science:

• Genetics
• Systems Biology
• Evolutionary Biology

Background:

• Complex traits are influenced by numerous genetic loci, often regulatory elements, exhibiting epistasis and pleiotropy.
• The omnigenic model suggests these interactions explain missed heritability in genome-wide association studies (GWAS).
• Understanding complex trait architecture is crucial for investigating their evolution under environmental pressures.

Purpose of the Study:

• To investigate the molecular basis of complex traits and their adaptive evolution.
• To analyze the distribution of SNP heritability across tissue-specific gene networks.
• To elucidate the role of network structure in complex trait heritability and evolution.

Main Methods:

• Systematic analysis of SNP heritability distribution for 11 traits.
• Examination across 29 tissue-specific expression quantitative trait locus (eQTL) networks.
• Network analysis to identify functionally relevant SNP-gene modules and regulatory hubs.

Main Results:

• SNP heritability is concentrated within specific tissue-specific, functionally relevant SNP-gene modules.
• Key heritability is localized in network
• hubs
• which are central to modules and act as tissue-specific regulatory elements.
• Network structure amplifies genotype-phenotype connections and buffers negative genetic effects, facilitating adaptation.

Conclusions:

• Complex trait architecture is characterized by clustered heritability in tissue-specific regulatory modules.
• Network hubs are critical for trait heritability, adaptation, and are targets of natural selection.
• This framework advances understanding of complex trait genetic architecture and evolutionary dynamics.