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