Octopuses rewire their brains to adapt to seasonal temperature shifts
Octopuses don't thermoregulate, so their powerful brains are exposed to -- and potentially threatened by -- changes in temperature. Researchers report June 8 in the journal Cell that two-spot octopuses adapt to seasonal temperature shifts by producing different neural proteins under warm versus cool conditions. The octopuses achieve this by editing their RNA, the messenger molecule between DNA and proteins. This rewiring likely protects their brains, and the researchers suspect that this unusual strategy is used widely amongst octopuses and squid.
"We generally think that our genetic information is fixed, but the environment can influence how you encode proteins, and in cephalopods this happens on a massive scale," says senior author Joshua Rosenthal of the Marine Biological Laboratory of Woods Hole, Massachusetts.
Compared to DNA mutations, which allow organisms to adapt over the course of generations, RNA editing offers a temporary and flexible way for individuals to adapt to environmental changes. RNA editing occurs across the tree of life, but RNA recoding -- when the editing changes the subsequent protein structure -- is much rarer, except in soft-bodied cephalopods like octopuses and squid. Humans have millions of editing sites but editing affects the protein products in only ~3% of their genes, whereas coleoid or "smart" cephalopods recode the majority of their neural proteins.
