What makes an octopus an octopus?
Researchers are now much closer to answering that question, thanks to an international team of scientists that has sequenced the genome of the common California two-spot octopus (also known as Octopus bimaculoides).
In their research, which will be published in Thursday's issue of the journal Nature, the scientists found significant differences between the genomes of the octopus and other invertebrates. These differences will help researchers better understand the unique traits of octopuses, such as their ability to change skin color and texture and the way an octopus’s distributed brain allows its eight arms to move independently of one another.
"The octopus genome makes studies of cephalopod traits much more tractable, and now represents an important point on the tree of life for comparative evolutionary studies," said Clifton Ragsdale, a neurobiology professor at the University of Chicago who co-led the study, in a statement. “It is an incredible resource that opens up new questions that could not have been asked before about these remarkable animals.”
Understanding the way an octopus’s brain interacts with its legs could help engineers design more effective arms for underwater robots, researchers say. Additionally, the genome could shed light on the genetic basis for other octopus traits, such as their ability to regenerate their limbs, a propulsion system that allows them to jet around underwater, and the suckers on their tentacles, which can feel and grasp and sense chemicals in the water.
"This will guide studies that until right now, today, we might not have thought were possible," Christine Huffard of the Monterey Bay Aquarium Research Institute, who was not involved in the research, told the Washington Post. "Next month or a year from now we’ll hopefully be doing much more complex behavioral studies because of it."
The genome is also expected to help with studies of other species belonging to the cephalopod class, such as squid, cuttlefish, and nautilus. Cephalopods have existed in various forms as ocean predators for around 400 million years, and were the first intelligent beings on the planet, according to Nobel laureate Sydney Brenner, who initiated the project.
"The reason for looking broadly at several different types of cephalopods is to see what is conserved among them," he said. "What is similar among all cephalopods is probably important to being a cephalopod."