Chromosomes May Have Both Compact Organization, Fast Subdiffusive Dynamics

Chromosomes exhibit both compact globular organization and fast subdiffusive dynamics, according to a new study appearing in Science. In it, researchers from the US, Austria, and elsewhere conducted live imaging of enhancer-promoter pairs in developing flies and examined their transcriptional output, while also varying the physical genomic separation of the enhancer-promoter pairs. They found that the chromosomal interactions reflected a combination of two polymer models, the Rouse model that predicts a loose structure and fast, random interactions between gene regions and the fractal globule model that predicts a tighter structure and slower interactions. According to the researchers, their findings suggest that the interactions of DNA regions may be less dependent on genomic distance than currently expected. "If such a system is in a fluid and dynamic state all the time, long-distance communication is much better than we might have thought," David Brückner, postdoctoral researcher and NOMIS fellow at the Institute of Science and Technology Austria, says in a statement.