Term Name:	constitutive heterochromatin formation
Synonyms:	constitutive heterochromatin assembly
Definition:	The compaction of chromatin into heterochromatin, a conformation that is refractory to transcription and in that involves the methylation of histone H3K9. Constitutive heterochromatin cannot be converted back to euchromatin, the transcriptionally-active conformation.
Ontology:	GO: Biological Process [GO:0140719]    QuickGO    AmiGO