Constitutive heterochromatin

During mitosis it is believed that constitutive heterochromatin is necessary for proper segregation of sister chromatids and centromere function.

Constitutive heterochromatin is replicated late in S phase of the cell cycle and does not participate in meiotic recombination.

[citation needed] Histone modifications are one of the main ways that the cell condenses constitutive heterochromatin.

[citation needed] SUV39H1 is a histone methyltransferase that methylates H3K9, providing a binding site for heterochromatin protein 1 (HP1).

[8][9] Genetic disorders that result from mutations involving the constitutive heterochromatin tend to affect cell differentiation and are inherited in an autosomal recessive pattern.

[citation needed] Some cancers are associated with anomalies in constitutive heterochromatin and the proteins involved in its formation and maintenance.