epis·​ta·​sis | \ i-ˈpi-stə-səs How to pronounce epistasis (audio) \
plural epistases\ i-​ˈpi-​stə-​ˌsēz How to pronounce epistasis (audio) \

Definition of epistasis

: suppression of the effect of a gene by a nonallelic gene

Other Words from epistasis

epistatic \ ˌe-​pə-​ˈsta-​tik How to pronounce epistasis (audio) \ adjective

Examples of epistasis in a Sentence

Recent Examples on the Web An observed trait may be the result of the interaction of changes in two or more genes simultaneously—a phenomenon called epistasis. William A. Haseltine, Forbes, 10 Dec. 2021 Another, though, is that the fates of mutations can be linked — an effect that population geneticists call synergistic, or narrowing, epistasis. Quanta Magazine, 13 July 2017 Most recent newsletter Kondrashov has investigated the implications of synergistic epistasis with theoretical studies. Quanta Magazine, 13 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'epistasis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of epistasis

circa 1917, in the meaning defined above

History and Etymology for epistasis

epi- + -stasis, after earlier epistatic, by analogy with metastatic : metastatis and like pairs

Note: The term epistatic was introduced, along with hypostatic, by the English biologist William Bateson (1861-1926) in "Facts Limiting the Theory of Heredity" ("Address delivered at the International Zoological Congress, before the Section of Cytology and Heredity, August 23, 1907"), Science, series 2, vol. 26 (July-December, 1907), issue of November 15, 1907, p. 653: "Till lately we spoke of the relations between the gray color of the mouse to the black color in terms of dominance …We can perhaps best express the relation between the gray and the black by the use of metaphor 'higher and lower,' and I therefore suggest the term epistatic as applicable to characters which have to be, as it were, lifted off in order to permit the lower or hypostatic character to appear."

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The first known use of epistasis was circa 1917

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Cite this Entry

“Epistasis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epistasis. Accessed 4 Jul. 2022.

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More Definitions for epistasis


epis·​ta·​sis | \ i-ˈpis-tə-səs How to pronounce epistasis (audio) \
plural epistases\ -​ˌsēz How to pronounce epistasis (audio) \

Medical Definition of epistasis

1a : 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

More from Merriam-Webster on epistasis

Britannica.com: Encyclopedia article about epistasis


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