Constitutive heterochromatin is formed at regions which don't have many coding genes. The majority of the DNA compacted into constitutive heterochromatin won't be needed in the lifetime of the organism and therefore doesn't become uncondensed at any point. Constitutive heterochromatin is present in the pericentromeric regions of chromosomes, which are made up of tandem repeats. It is also present in the telomeres of chromosomes, which are made up of the repeating 5'- TTAGGG-3' sequence.
- ↑ Armstrong L, Epigenetics. 1st Edition, New York: Garland Science. 2014
- ↑ BioMed Central, Saksouk N, Simboeck E, Déjardin J, Constitutive heterochromatin formation and transcription in mammals. 15th January 2015 [cited:03/12/2017]; Available from: https://epigeneticsandchromatin.biomedcentral.com/articles/10.1186/1756-8935-8-3