Researchers reveal how octopuses utilise RNA editing to alter their protein function, allowing them to acclimatise faster when encountering low temperatures
Animals’ ability to adapt to their environment never fails to surprise scientists, and octopuses are no different.
Focusing on genetics, researchers explain that each cell comes with a finite set of instructions encoded in its DNA – however, animals require flexibility in their changing environments.
Octopuses’ ability to acclimatise to their environment by altering protein function is now considered vital for their survival, but how are they doing it?
NSF-supported research led by Joshua Rosenthal of the Marine Biological Laboratory, and colleagues indicates that octopuses and their close relatives have found ways to elegantly adjust to environmental challenges.
When investigating cold water acclimation, the team of researchers documented an enormous uptick in RNA (an intermediary molecule that conveys DNA’s directions) editing in octopuses, squid and cuttlefish.
Through RNA editing, the cephalopods appear to have found a unique way of tweaking their own physiology, according to Rosenthal.
“We’re used to thinking all living things are preprogrammed from birth with a certain set of instructions,” he says. “The idea the environment can influence that genetic information, as we’ve shown in cephalopods, is a new concept.”
The idea the environment can influence that genetic information, as we’ve shown in cephalopods, is a new concept
As temperature governs the activity of enzymes, which in turn drive chemical reactions crucial to all physiological processes, researchers chose to focus on the effects of temperature on the nervous system.
After cooling the octopuses’ tanks, the team were able to see increases in protein-altering activity at more than 13,000 RNA sites in the animals’ nervous systems.
Increases in protein-altering activity at more than 13,000 RNA sites
Researchers then chose to investigate how swapping out a single letter of the RNA molecule’s code alters the function of proteins the neurons produce.
Like other cephalopods, the California two-spot octopus, Octopus bimaculoides, cannot generate its own body heat to counteract the temperature drops that accompany tides, changes in water depth and seasons.
After acclimating octopuses to temperatures at the warm end of their natural range (22 degrees C/ 72 degrees F) and the cool end (about 13 degrees C / 55 degrees F), the researchers examined their RNA.
Molecular coding for temperature variation
Within the molecular code, they tracked activity at locations where they already knew editing occurs. For octopuses in the cold tanks, they found significant increases in the protein-altering one-letter change at 13,285 sites. However, for those in the warm tanks, they found upticks at 550 such places.
“The discovery that shifts in water temperature cause rapid editing of the genetic information that codes for proteins key to nervous system function points to an ingenious mechanism by which octopuses, and potentially other animals, can adjust to change and achieve resilience in the face of environmental challenges,” said Edda Thiels, a program director in NSF’s Division of Integrative Organismal Systems.
An ingenious mechanism by which octopuses, and potentially other animals, can adjust to change and achieve resilience in the face of environmental challenges
