These researchers are looking at how the genome is organized in the
nucleus of the cell. They call it a dynamic three-dimensional
organization of the genome.
The DNA isn't just organized in chromosomes, but the compacted
chromosomes are arranged in the nucleus so that certain parts of the
genome are in close proximity to each other. There is a complex protein scaffold in the nucleus and large loops of DNA are created when the DNA
is attached to this scaffold and replicated. It gets to be a huge mess
and we have topoisomerases that relieve twisting of the double helix and
that can untangle knots.
Look up how enhancer sequences loop to link sequences that might range
out to 1 Mega base apart on the genome. These loops are dynamic and
change between cell types.