Each of us has enough DNA to reach from here to the sun and back, more than 300 times. How is all of that DNA packaged so tightly into chromosomes and squeezed into a tiny nucleus? Long ...

Some histones function as spools for the thread-like DNA to wrap around. Under the microscope in its extended form, chromatin looks like beads on a string. The beads are called nucleosomes.

The DNA (red) is wound around two sets of core histone proteins (green) to form a kind of bead on a string. The H1 histone protein clamps the DNA into place where it enters and exits a bead.

Studies have also have tapped into the nature of DNA’s primary packing material: protein spools called histones around which genomes wind to form nucleosomes. Nucleosomes, which are often compared to ...