Octopus brain complexity may be linked to how DNA folds in 3D
coleoid cephalopods
The group that includes octopuses, squid, and cuttlefish.
chromatin loop
A DNA contact that brings separated regions close together.
regulatory entanglement
A name for new gene-control connections formed by genome rearrangement.
What happened
Octopuses, squid, and cuttlefish belong to a group called coleoid cephalopods. They have large, highly structured nervous systems. They can solve problems and change color quickly. A University of Vienna team asked whether their complexity might reflect DNA’s three-dimensional arrangement, not only gene sequences. The study appeared in Nature Communications on October 9, 2026.
Background: DNA has a shape
DNA is a long sequence, but cells fold it inside the nucleus. Folding can bring distant DNA regions close together. Nearby regions can influence how strongly a gene is used. This does not mean that the DNA letters are rewritten. It means that cells may use the same genetic instructions differently.
An ancient coleoid ancestor experienced major genome rearrangements. Later lineages developed fusions, translocations, and repeated expansions of DNA. The researchers asked whether those old changes still shape genome organization today.
How the researchers tested the idea
The team compared three coleoid species. It examined several tissues and developmental stages. Micro-C mapped which DNA regions came close together. RNA sequencing measured gene activity. ATAC sequencing showed which DNA regions were easier for cells to access. Combining these methods connected DNA shape with gene regulation.
What the study found
Large chromatin domains were broadly conserved across the species. Smaller structures called chromatin loops were much more changeable. They differed between species, tissues, and developmental stages. Some loops appeared near genes involved in nervous-system development.
The researchers also disrupted a possible regulatory sequence inside one conserved loop. They tested the change in a close squid relative. The result supported a role for the loop in neural development. It also showed that some regulatory contacts can reach beyond larger chromatin domains.
The team calls this pattern regulatory entanglement. The phrase does not describe a literal knot. It describes new regulatory connections that may form after large genome rearrangements bring distant regions together. Some connections may become stable over evolutionary time.
This creates a possible balance. Large genome structures can preserve important organization. Flexible loops can create new gene-activity patterns. Together, they may help evolution produce new traits without changing every gene.
Why it matters
Evolution is often explained through changes in gene sequences. This study adds another layer. The same genes may work in new ways when their three-dimensional contacts change. That idea could help explain how cephalopods evolved complex nervous systems along a path different from vertebrates.
What remains unknown
The study does not prove that DNA folding alone created complex octopus brains. It does not identify every loop, gene, and behavior involved. The researchers also studied living species after a long history of evolution. That makes the original steps difficult to observe directly.
Future work can compare more cephalopods, tissues, and developmental stages. Researchers can also test more candidate regulatory regions. The key question is how a DNA contact changes a gene, a developing nervous system, and eventually an animal’s behavior.
Sources: the Nature Communications paper and the Phys.org report
Folded DNA may help explain octopus brains
📰 Full story: Octopus brain complexity may be linked to how DNA folds in 3D
A new study says DNA’s 3D shape may help control complex nervous systems.
3D genome
The folded, three-dimensional arrangement of DNA inside a cell.
chromatin loop
A small DNA connection that brings two regions close.
gene regulation
The process that controls when cells use genes.
💡 The gist
- Octopuses, squid, and cuttlefish have complex nervous systems.
- DNA folds into shapes inside every cell.
- Those shapes may change how genes work.
The University of Vienna, a research university in Austria, led the study. The study appeared in Nature Communications.
Scientists compared octopuses, squid, and cuttlefish. They studied several tissues and growth stages. They used tools that map DNA contacts and gene activity.
One tool shows which DNA regions sit close together. Another shows which genes are active. A third shows which DNA regions cells can easily use.
This whole folded system is called a 3D genome. Large DNA neighborhoods stayed similar across the animals. Smaller loops changed more often. These loops are called chromatin loops.
The loops differed between species, tissues, and growth stages. Some sat near genes linked with the nervous system. Genes are instructions that help cells do their jobs.
Researchers changed one control region inside a conserved loop. They tested it in a close squid relative. The change affected nervous-system development. This supports a role for DNA shape in gene regulation.
Gene regulation means how cells turn genes on or off. DNA folding can bring faraway control regions close. This may change which instructions cells use.
The study does not prove DNA folding alone built octopus brains. Scientists still need to connect specific loops with specific traits. Future studies may test more species and growth stages.
Could folded DNA help octopuses think?
📰 Full story: Octopus brain complexity may be linked to how DNA folds in 3D
Scientists found that DNA’s shape may help growing nerves.
DNA
A set of instructions that helps cells work.
nervous system
The body system that helps an animal sense and act.
The University of Vienna, a research university, studied octopuses and their relatives.
Octopuses, squid, and cuttlefish have busy nervous systems.
DNA holds instructions inside every tiny cell.
DNA folds up to fit inside cells.
Folding can bring faraway DNA parts close.
Then cells may use some instructions differently.
Scientists saw these contacts near nerve instructions.
They changed one small control part in a squid relative.
Its nerve growth changed.
This shows that DNA’s shape matters.
It does not explain everything about octopus brains.
Scientists still need more answers.