heterochromatin

American  

[het-er-uh-kroh-muh-tin] / ˌhɛt ər əˈkroʊ mə tɪn /

noun

Genetics.

1. the dense, highly stainable part of a chromosome.

---

heterochromatin British  

/ ˌhɛtərəʊˈkrəʊmətɪn /

noun

1. the condensed part of a chromosome that stains strongly with basic dyes in nondividing cells and has little genetic activity Compare euchromatin

---

Etymology

Origin of heterochromatin

First recorded in 1930–35; hetero- + chromatin

Example Sentences

See Examples For:

heterochromatin

Older APOE2 knock-in mice had smaller nucleoli, higher levels of the nuclear scaffolding protein Lamin A/C, and better-preserved heterochromatin in the hippocampus than mice carrying APOE3 or APOE4.

From Science Daily ● Jul. 24, 2026

In this analogy, dense regions of heterochromatin are like cities where people have many social interactions, while the rest of the genome is comparable to sparsely populated rural areas.

From Science Daily ● Nov. 16, 2023

Eukaryote chromosomes are wrapped around histone proteins that could form heterochromatin, which is present in prokaryotes.

From Textbooks ● Jun. 9, 2022

The tightly packaged region is known as heterochromatin, and the less dense region is known as euchromatin.

From Textbooks ● Jun. 9, 2022

Animals also use small RNA-directed DNA methylation and heterochromatin formation mechanisms to maintain the epigenome of the germ line through the use of Piwi-interacting RNAs.

From Nature ● Mar. 13, 2013