Octopuses are able to survive cold temperatures by editing their genetic material in less than a day, scientists have found.
Researchers have discovered that the creatures are able to make changes to their RNA – a complex molecule essential for life – within hours of being exposed to cold water.
Previous studies have shown that squid and octopuses can edit their genes but this is the first time scientists have established how rapidly these changes can occur.
The researchers said their new findings, published in the journal Cell, were “a tip of the iceberg” shedding further light on the sophisticated behaviour of octopuses.
The creatures have the ability to perform complex tasks and have been shown to do puzzles like unscrewing a lid on a jar.
They can also mimic colours and textures to camouflage themselves, as well as regrow a lost arm.
For the study, scientists in the US analysed the behaviour of the California two-spot octopus (Octopus bimaculoides).
Unlike humans, octopuses are not capable of generating their own heat to counteract temperature changes.
We could see significant changes in less than a day, and within four days they were at the new steady-state levels that you find them in after a month— Matthew Birk, Marine Biological Laboratory
The researchers acclimatised adult octopuses to warm (22C) or cold (13C) waters in tanks at the Marine Biological Laboratory in Chicago.
After several weeks, they examined the RNA of the octopuses to see if there were any changes in the molecular code.
They looked for signs of editing at over 60,000 previously identified RNA editing sites in the octopus.
Co-senior study author Eli Eisenberg, of Tel-Aviv University, said: “Temperature-sensitive editing occurred at about one-third of our sites – over 20,000 individual places.”
We're used to thinking all living things are preprogrammed from birth with a certain set of instructions. The idea the environment can influence that genetic information, as we've shown in cephalopods, is a new concept— Joshua Rosenthal, Marine Biological Laboratory
The researchers then performed further experiments on juvenile octopuses to see how quickly the changes occurred.
They gradually heated or cooled water tanks – from 14C to 24C or vice versa – at 0.5C hourly increments for around 20 hours, measuring the extent of RNA editing at several points in time.
Matthew Birk, who led the project as a postdoctoral fellow at the Marine Biological Laboratory, said: “We could see significant changes in less than a day, and within four days they were at the new steady-state levels that you find them in after a month.”
Joshua Rosenthal, of the Marine Biological Laboratory, who led the study, said: “We’re used to thinking all living things are preprogrammed from birth with a certain set of instructions.
“The idea the environment can influence that genetic information, as we’ve shown in cephalopods, is a new concept.”
