Credit: AAAS

Science 326, 289–293 (2009)

The three-dimensional structure of the human genome has been mapped. Job Dekker of the University of Massachusetts Medical School in Worcester, Eric Lander of the Broad Institute in Cambridge, Massachusetts, and their co-workers identified segments of the genome that tend to sit close together. They then used next-generation sequencing technology to build up a map showing the proximity of the segments to each other — a novel method they call 'Hi-C'.

The team found that each chromosome weaves between two compartments: one contains active genes; the other, more compact compartment houses inactive stretches of the genome. On a larger scale, the chromosomes are tightly packed into a 'fractal globule' (pictured) that remains unknotted to allow easy access to genes.