Segments of DNA that serve to isolate neighboring genes within a specific domain by blocking interactions between enhancers (q.v.) on one side of a domain from the inappropriate target promotors of neighboring genes belonging within an adjacent domain. Specific proteins that bind to insulator DNA segments are responsible for defining certain chromosomal regions, such as the interbands and puff boundaries in polytene chromosomes. See Chronology, 1995, Zhao, Hart, and Laemmli; 2000, Bell and Felsenfeld; H19, matrix attachment regions, parental imprinting.
Subjects: Genetics and Genomics.