Short-range regulatory chromatin loops in plants.

In all eukaryotic organisms, gene expression correlates with the condensation state of the chromatin. Highly packed genome regions, known as heterochromatins, are associated with repressed loci, whereas euchromatic regions represent a relaxed state of the chromatin actively transcribed. However, even in these active regions, associations between chromatin domains dynamically modify genome topology and alter gene expression. Long-range interaction within and between chromosomes determines chromatin domains that help to coordinate transcriptional events. On the other hand, short-range chromatin interactions emerged as dynamic mechanisms regulating the expression of specific loci. Our current capacity to decipher genome topology at high resolution allowed us to identify numerous cases of short-range regulatory chromatin interactions, which are reviewed in this Insight article.