1. The formation of a pellicle or scum on the surface of a liquid, especially as on standing urine. 2. Phenotypic interaction of non-allelic genes. 3. A form of gene interaction whereby one gene masks or interferes with the phenotypic expression of one or more genes at other loci; the gene whose phenotype is expressed is said to be “epistatic,” while the phenotype altered or suppressed is then said to be “hypostatic.” SYN: epistasy. [G. scum; epi- + G. stasis, a standing]
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1 a) suppression of a secretion or discharge
b) a scum on the surface of urine
2) suppression of the effect of a gene by a nonallelic gene <the role of \epistasis in polygenic inheritance>
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n.
1. the stopping of a flow or discharge, as of blood.
2. a type of gene action in which one gene can suppress the action of another (nonallelic) gene. The term is sometimes used for any interaction between nonallelic genes.
• epistatic adj.
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epis·ta·sis (ə-pisґtə-sis) [epi- + stasis] 1. suppression of a secretion or excretion, as of blood, menses, or lochia. 2. a scum on the surface of urine. 3. the interaction between genes at different loci that results in one gene masking the expression of the other. Cf. dominance.Medical dictionary. 2011.