Scientists have just made a very big discovery about octopi, along with squid and cuttlefish, that could totally change how we think about them.
A remarkable new study claims something astonishing about octopi, along with their squid and cuttlefish cousins, that indicate that these animals are a lot more intelligent than we give them credit for. They’ve long been known for remarkable escapes by squeezing into small areas or unscrewing glass jars from the inside, but this study claims that octopi are able to ignore their own DNA information, in a sense.
The “central dogma” of molecular biology holds that cells convert DNA sequences to RNA, which then manufactures the proteins that define their traits. Occasionally, cells will edit this RNA by removing adenosine and inserting inosine. What’s interesting about cephalopods is that they sometimes use the altered RNA to generate new proteins.
This RNA editing enables an octopus gene to produce different types of proteins, all from the same DNA. This further allows cephalopods to ignore RNA and come up with their own “recipes.” The study found that cephalopods frequently edit their RNA, and do it more than any other species.
“Octopuses, squid, and cuttlefish often do not follow the genetic instructions in their DNA to the letter,” reads the statement from Cell Press. “Instead, they use enzymes to pluck out specific adenosine RNA bases (some of As, out of the As, Ts, Gs, and Us of RNA) that codes for proteins and replace them with a different base, called Inosine. This process–called “RNA editing”–is rarely used to recode proteins in most animals, but octopuses and their kin edit RNA base pairs in over half of their transcribed genes. When researchers did experiments to quantify and characterize the extent of this RNA editing across cephalopod species, they found evidence that this genetic strategy has profoundly constrained evolution of the cephalopod genome. The study appears in Cell on April 6.
“Researchers have found that octopuses use RNA editing to rapidly adapt to temperature changes and that the majority of RNA transcripts in squid neurons contain these edits. In the new study, researchers hoped to find out how commonplace these edits are, how they evolved along the cephalopod lineage, and how such extraordinary editing capabilities affect the evolution of the cephalopod genome.”