Dictionary > Epistasis

Epistasis

Definition
noun, plural: epistases
(genetics) The interaction between nonallelic genes at two or more loci resulting in one gene masking the phenotypic expression of another gene
(medicine) The arrest of a secretion or bodily discharge
Supplement
In genetics, epistasis pertains to the interaction of the genes at two or more loci, and as a result the effect of the gene depends on the presence of one or more modifier genes. There is that one gene or allele masking the phenotypic expression of the other genes or alleles in the interaction. That gene or allele masking the effect is referred to as epistatic. In contrast, the other gene(s) or allele(s) being masked is/are referred to as hypostatic. Epistasis may be recessive or dominant. An example of epistasis is the fur color of Labrador retrievers, which is a polygenic trait. Two genes are interacting to determine its fur color. One gene (represented by B) determines the fur color whereas the other gene (represented by E) controls the expression of the gene B. The presence of homozygous recessive alleles ee would mask the gene B (regardless of the dominant B alleles). This is an example of recessive type of epistasis.
Word origin: Greek epĂ­stasis (stopping, stoppage)
See also:


You will also like...

Neural Control Mechanisms
Neural Control Mechanisms

Neurons generate electric signals that they pass along to the other neurons or target tissues. In this tutorial, you wil..

Adaptation Tutorial
Adaptation Tutorial

Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

Lake Wakatipu, New Zealand
New Zealand’s Unique Geographical History

Explore why New Zealand has such unique flora and fauna, and learn why long periods of geographical isolation. This less..

Plant biology
Plant Biology

Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

Origins of Life on Earth
Origins of Life on Earth

Earth was created around 4.5 billion years ago and life began not long after. Primitive life likely possessed the elemen..

Growth Patterns
Growth Patterns

This tutorial describes the sigmoid curve, annual plant growth, tree growth, human growth, and insect growth as the grow..