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

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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 Another, though, is that the fates of mutations can be linked — an effect that population geneticists call synergistic, or narrowing, epistasis. Quanta Magazine, "Missing Mutations Suggest a Reason for Sex," 13 July 2017 Most recent newsletter Kondrashov has investigated the implications of synergistic epistasis with theoretical studies. Quanta Magazine, "Missing Mutations Suggest a Reason for Sex," 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

New Latin, from Greek, act of stopping, from ephistanai to stop, from epi- + histanai to cause to stand — more at stand

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Time Traveler for epistasis

Time Traveler

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 28 Jan. 2021.

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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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