octopus from the Arctic tweaks its RNA to make nervous system proteins that work better in the cold.

To endure the cold, octupus living in the freezing cold waters o the Antarctica use a trick called RNA editing to produce proteins that work that work at low temperatures. The proteins excreted by the nervous sytem to send signals don't work efficiently. After a nerve cell fires and the electrical charge across the cell membrane comes to normal, the potassium ions are shut out out of the ion channels but at cold temperatures the potassium channel's closing can be delayed thus slowing down the neuron. Researchers thought that animals living in these cold temperatures might have modified their postassium channels so they work better in the cold. 



 Molecular neurophysiologist Joshua Rosenthal of the University of Puerto Rico Medical Sciences Campus in San Juan and his graduate student Sandra Garrett figured they knew how that adjustment would occur. "We thought we were going to see changes at the level of the gene," Rosenthal says. But instead they use RNA editing, to change a protein. During RNA editing, cells change the nucleotide sequence of the RNA which changes the sequence of amino acids in the resulting protein and change the protein's function. The Antarctic octopus edits its RNA at nine sites that change the amino acid sequence of the potassium channel.

Other researchers praise the study for revealing a new way for organisms to adapt. "There's this whole different molecular mechanism for increasing protein diversity," says molecular neurobiologist Ronald Emeson of the Vanderbilt University Medical Center in Nashville.