Just when we thought octopuses couldn’t be any weirder, it turns out that they and their cephalopod brethren evolve differently from nearly every other organism on the planet.
In a surprising twist, in April 2017 scientists discovered that octopuses, along with some squid and cuttlefish species, routinely edit their RNA (ribonucleic acid) sequences to adapt to their environment.
This is weird because that’s really not how adaptations usually happen in multicellular animals. When an organism changes in some fundamental way, it typically starts with a genetic mutation – a change to the DNA.
Those genetic changes are then translated into action by DNA’s molecular sidekick, RNA. You can think of DNA instructions as a recipe, while RNA is the chef that orchestrates the cooking in the kitchen of each cell, producing necessary proteins that keep the whole organism going.
But RNA doesn’t just blindly execute instructions – occasionally it improvises with some of the ingredients, changing which proteins are produced in the cell in a rare process called RNA editing.
When such an edit happens, it can change how the proteins work, allowing the organism to fine-tune its genetic information without actually undergoing any genetic mutations. But most organisms don’t really bother with this method, as it’s messy and causes problems more often that solving them.
“The consensus among folks who study such things is Mother Nature gave RNA editing a try, found it wanting, and largely abandoned it,” Anna Vlasits reported for Wired.
But it looks like cephalopods didn’t get the memo. Read more …