chromatin

noun

chro·​ma·​tin ˈkrō-mə-tən How to pronounce chromatin (audio)
: a complex chiefly of DNA and histone in eukaryotic cells that is usually dispersed in the interphase nucleus and condensed into chromosomes in mitosis and meiosis and in which the nucleosome makes up its repeating subunits
In eukaryotes, the DNA interacts with the histone proteins to form a tightly packed superstructure known as chromatin.Isao Tanaka et al.
see cell illustration compare euchromatin, heterochromatin, nucleosome
chromatinic adjective

Examples of chromatin in a Sentence

Recent Examples on the Web Normally, after death, chromatin molecules break apart and diffuse through the cellular matrix, like sugar dissolving in hot coffee. Richard Stone, science.org, 11 July 2024 How chromatin is structured determines which of its genes are accessible and can be transcribed; if parts of chromatin are too tightly packed, the enzyme machinery of transcription can’t reach it. Philip Ball, Scientific American, 14 May 2024 Another idea is that lncRNAs affect the structure of chromatin—the combination of DNA and proteins that makes up chromosome fibers in the cell nucleus. Philip Ball, Scientific American, 14 May 2024 Every organism on the planet has a genome, and almost all organisms organize it into a structure called chromatin. Anika Nayak, STAT, 13 Oct. 2023 To access a gene, the chromatin must be unpacked in a way that reveals the precise location of the gene and then packed away again afterwards. The Physics Arxiv Blog, Discover Magazine, 9 Aug. 2023 It is controlled by methylation changes to CpG islands on promoter regions, the remodeling of chromatin using histone modifications, and the alteration of gene expression through non-coding RNA expression. Salvatore Viscomi, Forbes, 22 Mar. 2023 Methylation is a process by which, in the presence of specific enzymes, methyl groups attach to key sites on a strand of DNA or within the complex of DNA and proteins known as chromatin. Rachel Yehuda, Scientific American, 18 June 2022 The researchers eventually zeroed in on two key enzymes that affect the structure and, as a consequence, function of chromatin. Gabriel A. Silva, Forbes, 5 Apr. 2021

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'chromatin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

borrowed from German Chromatin "dense part of the cell nucleus that is easily stained," from Greek chrōmat-, chrôma "color" + German -in -in entry 1

Note: Term introduced by German biologist Walther Flemming (1843-1905) in "Beiträge zur Kenntnis der Zelle und ihrer Lebenserscheinungen, Theil II," Archiv für mikroskopische Anatomie, Band 18 (1880), pp. 157-58.

First Known Use

1882, in the meaning defined above

Time Traveler
The first known use of chromatin was in 1882

Dictionary Entries Near chromatin

Cite this Entry

“Chromatin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/chromatin. Accessed 15 Oct. 2024.

Kids Definition

chromatin

noun
chro·​ma·​tin ˈkrō-mə-tən How to pronounce chromatin (audio)
: a material present in chromosomes that is made up of DNA and protein and stains deeply with certain biological stains

Medical Definition

chromatin

noun
chro·​ma·​tin ˈkrō-mət-ən How to pronounce chromatin (audio)
: a complex of a nucleic acid with basic proteins (as histone) in eukaryotic cells that is usually dispersed in the interphase nucleus and condensed into chromosomes in mitosis and meiosis
chromatinic adjective

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