1. A genetic interaction in which one gene suppresses or masks the effect of another gene at a different location on the chromosome.
Usage: genetics; technical

Examples

• In fruit flies, epistasis occurs when a gene for eye color masks the expression of a gene for body color.
• The geneticist studied epistasis to understand how multiple genes interact to produce a single trait.
• Epistasis complicates the prediction of offspring phenotypes in crosses involving multiple genes.
• The white eye mutation in Drosophila is a classic example of epistasis in introductory biology courses.
• Researchers must account for epistasis when mapping genes responsible for complex traits.