Epistasis and Its Contribution to Genetic Cariance Components
Cheverud JM, Routman EJ
Department of Anatomy and Neurobiology, Washington University School of Medicine,
St. Louis, Missouri 63110, USA.
Genetics, 139(3):1455-1461 (1995)
Abstract
We present a new parameterization of physiological epistasis that allows the
measurement of epistasis separate from its effects on the interaction (epistatic) genetic
variance component. Epistasis is the deviation of two-locus genotypic values from the
sum of the contributing single-locus genotypic values. This parameterization leads to
statistical tests for epistasis given estimates of two-locus genotypic values such as can
be obtained from quantitative trait locus studies. The contributions of epistasis to the
additive, dominance and interaction genetic variances are specified. Epistasis can make
substantial contributions to each of these variance components. This parameterization
of epistasis allows general consideration of the role of epistasis in evolution by defining
its contribution to the additive genetic variance.
Variance component linkage analysis