Identification of response-modulated genetic interactions by sensitivity-based epistatic analysis

Area of Science:

• Systems Biology
• Genomics
• Molecular Biology

Background:

• High-throughput genomics enables mapping genetic interactions via phenotypic impact of perturbations.
• Understanding dynamic network remodeling in response to environmental stimuli is a critical next step.
• Current methods primarily focus on fitness, limiting insights into environmentally modulated interactions.

Purpose of the Study:

• To develop and test a novel method for identifying dynamic genetic interactions.
• To adapt first-principles analysis of environmental perturbations to gene deletions.
• To establish a neutrality function based on sensitivity phenotypes rather than fitness.

Main Methods:

• Developed a novel neutrality function treating environmental perturbations like gene deletions.
• Applied the method to budding yeast (Saccharomyces cerevisiae) using transcription factor and DNA repair gene deletion libraries.
• Identified fitness- and sensitivity-based genetic interactions in response to drug-induced DNA damage.

Main Results:

• Significant differences observed between fitness- and sensitivity-based genetic interaction sets.
• Sensitivity-based interactions are modulated by drug-induced DNA damage, while fitness-based ones remain invariant.
• Sensitivity-based method improves identification of DNA damage response interactions and functional grouping of DNA repair genes.

Conclusions:

• Incorporating environmental effects into neutrality functions enhances identification of response-modulated genetic interactions.
• This approach facilitates dynamic gene network modeling from quantitative genetic interaction data.
• The method is adaptable for various phenotypes beyond cellular growth.