The mystery of the octopus genome has finally been solved, and this will allow researchers to answer some intriguing questions: how does it regenerate so well? How does it control its 8 flexible arms and over 1000 suckers? How do they camouflage and mimic the environment, and most importantly – how did a relative of the snail become so incredibly smart?
Cephalopod intelligence is extremely important because it relies on an entirely different nervous systems to that of mammals. The cephalopod class of molluscs, particularly the Coleoidea subclass are highly intelligent invertebrates, but they’re… different from us. Scientists don’t really understand it that well, and the fact that most cephalopods are so elusive doesn’t help them – so they took the other way about it: they analyzed their DNA.
The findings, published today in Nature, reveal a vast, unexplored landscape full of novel genes and surprising gene arrangements, including some evolutionary aspects which are remarkably similar to those in humans. Among these, of special significance are a large group of familiar genes which are encountered in several mammal species, including humans, and which offer increased mental processing power. Known as protocadherin genes, they “were previously thought to be expanded only in vertebrates,” says Clifton Ragsdale, an associate professor of neurobiology at the University of Chicago and a co-author of the new paper.
How and why they were able to develop such remarkable features will be a rich area of research, and biologists are excited to get on the case.
“For neurobiologists, it’s intriguing to understand how a completely distinct group has developed big, complex brains,” says Joshua Rosenthal of the University of Puerto Rico’s Institute of Neurobiology. “Now with this paper, we can better understand the molecular underpinnings.”
Also revealed through this study are genes that allow octopuses to taste through their suckers. Researchers can also now better study the past of this rarely fossilized animal’s evolutionary history – a history which goes back 270 million years.
It was no easy feat, but unraveling the octopus genome will pave the way for a myriad of other discoveries, from neurobiology to evolution to engineering.
“This is such an exciting paper and a really significant step forward,” says Lindgren, who studies relationships among octopuses, which have evolved to inhabit all of the world’s oceans—from warm tidal shallows to the freezing Antarctic depths. For her and other cephalopod scientists, “having a whole genome is like suddenly getting a key to the biggest library in the world that previously you could only look into by peeking through partially blocked windows.
I for one, can’t wait.
