chromatin

noun

chro·​ma·​tin ˈkrō-mə-tən 

: 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

ˌkrō-mə-ˈti-nik 

adjective

Examples of chromatin in a Sentence

Recent Examples on the Web

And number two, my first scientific paper in my own career was about applying math to the structure of the chromatin fiber. —Steven Strogatz, Quanta Magazine, 5 Dec. 2024

For a gene to be transcribed, chromatin must open to make DNA more accessible. —William A. Haseltine, Forbes, 1 Nov. 2024

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

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

Phrases Containing chromatin

• sex chromatin

Kids Definition

chromatin

noun

chro·​ma·​tin ˈkrō-mə-tən 

: 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 

: 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

ˌkrō-mə-ˈtin-ik 

adjective