DNA packaging scale
Eukaryotic genomes are compacted through successive packaging levels. Step through the hierarchy commonly taught in molecular biology courses.
- DNA double helix~2 nm wide information polymer
- Nucleosomes“Beads on a string” chromatin
- Chromatin fiberFurther folding of nucleosomal arrays
- Higher-order loops/domainsOrganized nuclear architecture
- Mitotic chromosomeMaximally compacted for segregation
Start with the DNA double helix, then wrap it into nucleosomes — the first major packaging step in eukaryotes.