Heterochromatin

Name:
Heterochromatin
Detailed information:
Chromatin which is in a condensed, less accessible state and thus frequently transcriptionally silent. However, some DNA is constitutive heterochromatin (e.g. the second X chromosome is inactivated to a Barr body for dosage compensation) whereas other DNA is facultative heterochromatin. An example might be genes required under time of stress only, or during a stage of the cell cycle.