DNA insulators

Definition: Insulators are DNA sequence elements that prevent inappropriate interactions between adjacent chromatin domains.

One type of insulator establishes domains that separate enhancers and promoters to block their interaction, whereas a second type creates a barrier against the spread of heterochromatin.

The mechanisms of action of both enhancer blockers and barriers might not be unique to these types of element, but instead are adaptations of other gene-regulatory mechanisms.

References

 Gaszner M, Felsenfeld G. Insulators: exploiting transcriptional and epigenetic mechanisms. Nat Rev Genet. 2006 Sep;7(9):703-13. PMID: 16909129