DNA double helix to chromosomes

Wrapping of DNA around histone proteins

step 1

Formations of 3D zigzag structure via histone H1 and other DNA-binding proteins (30 nm fibers)

step 2

Anchoring of radial loop domains into the nuclear matrix

step 3

1. Further compaction of radial loops to form heterochromatin

step 4

Metaphase chromosome with 2 copies of DNA

step 5