Chromatin boundaries or insulators modulate enhancer-promoter interactions in complex genetic loci. However, the mechanism underlying insulator activity is not known. Previous studies showed that the activity of the Drosophila suHw insulator is abolished by the tandem arrangement (pairing) of the insulator elements, suggesting that interactions between insulators or like elements may be involve...

Chromatin insulators, or boundary elements, affect promoter-enhancer interactions and buffer transgenes from position effects. The gypsy insulator of Drosophila is bound by a protein complex with two characterized components, the zinc finger protein Suppressor of Hairy-wing [Su(Hw)] and Mod(mdg4)2.2, which is one of the multiple spliced variants encoded by the modifier of mdg4 [mod(mdg4)] gene....

Transcriptional insulators are specialized cis-acting elements that protect promoters from inappropriate activation by distal enhancers. The H19 imprinting control region (ICR) functions as a CTCF-dependent, methylation-sensitive transcriptional insulator. We analyzed several insertional mutations and demonstrate that the ICR can function as a methylation-regulated maternal chromosome-specific ...

Chromatin boundaries or insulator elements affect the interaction between enhancers and promoters. The gypsy insulator contains two proteins, Su(Hw) and Mod(mdg4). Both proteins colocalize on several hundred sites on polytene chromosomes and are distributed in a punctated pattern in the nuclear matrix. Mutations in mod(mdg4) have properties characteristic of a trxG gene. In addition, mutations ...

CTCF plays a central role in vertebrate insulators and forms part of the Fab-8 insulator in Drosophila. dCTCF is present at hundreds of sites in the Drosophila genome, where it is located at the boundaries between bands and interbands in polytene chromosomes. dCTCF colocalizes with CP190, which is required for proper binding of dCTCF to chromatin, but not with the other gypsy insulator proteins...

The chalking of composite insulators is referred to a kind abnormal aging the silicone rubber sheds. It has serious adverse effects on long-term operation insulators, but mechanism behind its generation and development remains unclear. In order deeply understand phenomenon insulator chalking, this paper took chalked operating extra-high voltage (EHV) AC 500 kV as samples for research. Appearanc...