Cephalopod RNA Is Edited More Often Than a Reused Mixtape
An animal's adaptability is tied to its genetic makeup, but for a long time we've had a limited window into how this process works. It goes something like this: DNA is copied into RNA, which codes for particular proteins and lays out the proper amino acid sequence for building them. You can change how those proteins are expressed, says the model, but if you want different ones, then for the most part, you need different DNA. Editing RNA is possible, but rare and usually not important.
Well, don't tell that to squids and octopuses, both of which majorly edit their RNA, according to recent research. This tweaking enables the cephalopods to build proteins for which their DNA lacks a blueprint. In fact, it allows them to make several different proteins from identical strands of RNA [sources: Alon et al.; Baggaley].
Researchers suspect that such abilities might exist elsewhere in the animal world and could provide a more rapid response to environmental requirements than waiting for DNA mutations. At least one octopus study, published in the February 2012 issue of Science, bears this out. It reveals that Antarctic and Arctic species of octopuses use RNA editing to correct neural imbalances brought on by colder waters [sources: Courage; Garrett and Rosenthal].