blas·​to·​cyst | \ ˈbla-stə-ˌsist How to pronounce blastocyst (audio) \

Definition of blastocyst

: the modified blastula of a placental mammal having an outer layer composed of the trophoblast

Examples of blastocyst in a Sentence

Recent Examples on the Web The science journal Nature reports that scientists have created a structure like a blastocyst – an early embryo – using mouse stem cells instead of the usual sperm and egg. Cnn Editorial Research, CNN, 28 May 2021 Under certain culture conditions, the cells can form each of the three cell types in the blastocyst, researchers previously found. Mitch Leslie, Science | AAAS, 17 Mar. 2021 The teams behind the new work hope their blastocyst-like models could provide a ready supply of stand-ins for the real thing and a better imitation than mouse blastoids. Andrew Joseph, STAT, 19 Mar. 2021 Many miscarriages occur during this stage, for example, and a blastocyst can also split to create twins. Mitch Leslie, Science | AAAS, 17 Mar. 2021 The embryologist walks in and shows us our blastocyst., 27 Oct. 2020 My twins were formed when a blastocyst collapsed in on itself—but then, instead of dying, doubled. Sarah Stewart Johnson, The New Yorker, 4 Oct. 2020 Science asked several researchers who have expertise in DNA sequencing about Rebrikov’s plan to search for off-target effects in blastocysts. Jon Cohen, Science | AAAS, 21 Oct. 2019 But there could be other cells in the blastocyst that have unaltered GJB2 genes or off-target changes. Jon Cohen, Science | AAAS, 21 Oct. 2019

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

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First Known Use of blastocyst

1876, in the meaning defined above

History and Etymology for blastocyst

blasto- + -cyst

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Time Traveler for blastocyst

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The first known use of blastocyst was in 1876

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Cite this Entry

“Blastocyst.” Dictionary, Merriam-Webster, Accessed 23 Sep. 2021.

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More Definitions for blastocyst


blas·​to·​cyst | \ ˈblas-tə-ˌsist How to pronounce blastocyst (audio) \

Medical Definition of blastocyst

: the modified blastula of a placental mammal

More from Merriam-Webster on blastocyst Encyclopedia article about blastocyst


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