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Published on: November 12, 2012
Modularity and interactions in the genetics of gene expression
Oren Litvin1, Helen C Causton, Bo-Juen Chen
1Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Summary
Genetic variation significantly impacts phenotypes through widespread, nonadditive interactions between gene expression loci. These interactions reveal complex regulatory networks influencing biological pathways and cellular states.
Area of Science:
- Genetics
- Systems Biology
- Statistical Genetics
Background:
- Understanding how genetic sequence variation influences observable traits (phenotypes) is a fundamental challenge in genetics.
- Gene expression quantitative trait loci (eQTLs) are key components in linking genetic variation to gene expression and, subsequently, to phenotype.
Purpose of the Study:
- To develop and apply a statistical method, GOLPH (GenOmic Linkage to PHenotype), for identifying genetic interactions.
- To characterize the landscape of genetic interactions among eQTLs and their impact on phenotype.
Main Methods:
- Development of GOLPH, a novel statistical framework for detecting genetic interactions.
- Application of GOLPH to analyze interactions between eQTLs.
- Analysis of how these interactions affect gene expression modules and biological pathways.
Main Results:
- Identified widespread allele-specific genetic interactions, where a gene's phenotypic effect depends on the allele at another locus.
- Demonstrated that genetic interactions are predominantly nonadditive.
- Showed that genetic variation can profoundly alter global transcriptional responses by modulating pathway interactions.
Conclusions:
- Genetic interactions, particularly allele-specific and nonadditive ones, are prevalent and shape complex phenotypes.
- Interacting loci coordinate the expression of gene modules involved in coherent biological processes.
- Intrinsic genetic variation can drive distinct cellular states, similar to environmental influences.
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