For decades, scientists have used mice to better understand behavior and disease. Mice are great for experiments because they are easy to hold in captivity and they reproduce quickly.
“With these organisms, you could understand what genes did by manipulating them,” says biologist Josh Rosenthal. “And that really became an indispensable part of biology.”
Rosenthal works at the Marine Biological Lab in Woods Hole, Massachusetts, where his team is using octopuses and squids instead of lab rats to run experiments.
[IMAGE 1] Octopuses and squids belong to a class of predatory mollusks called cephalopods – ocean-dwelling creatures whose evolutionary history spans more than 500 million years.
“They were the first intelligent beings on the planet,” says Professor Sydney Brenner from the Okinawa Institute of Science and Technology. In 2015, Brenner’s team successfully sequenced and analyzed the genome of the California two-spot octopus (the first time this had been done for any cephalopod).
“I ended up sequencing the octopus genome because I’m interested in how you make a weird animal,” jokes Carrie Albertin, a member of Brenner’s team who now works at the Massachusetts lab. “Most of their genes have some similarity to genes that we have and other animals have…But they seem just so otherworldly.”
In studying the genome of the California two-spot octopus, the team discovered hundreds of unique genes that don’t appear in any other animal. The team believes these genes may be involved in the octopus’s camouflage process.
Researchers at the Massachusetts lab hope to continue this research by studying traits such as:
- The ability to regrow limbs
- Chemosensory suckers
- Jet propulsion system
- Three heart circulatory system
- Camouflage ability
- Learning and problem-solving abilities
Ideally, this research will uncover biological adaptations and solutions that mice were unable to provide.
But the task is difficult. Unlike mice, octopuses are big, smart, and aggressive. Each specimen must be held in a separate enclosure and tanks must be secured tightly to prevent escape.
One of the team’s favorite octopus species is the pygmy zebra octopus because it reproduces often and grows no larger than a grape. The team is also studying the California two-spot octopus.
As of mid-June, the Massachusetts lab had more than 3,000 individual cephalopods under its care.
“It’s the only place on the planet that you can go where we are culturing a number of these species through every life stage, through successive generations, with the goal of creating a genetically tractable system,” says Bret Grasse, head of the Massachusetts team. “We’re going to continue to scale this program as more and more scientific communities become involved. We’ve already seen a great response in the two years that we’ve been here.”
Once a species’ genome has been mapped, the team can tinker with its genes (as we have done with mice). As their research progresses, Grasse and his colleagues are very aware of the potential ethics surrounding their work – especially because there are no federal rules concerning the treatment of octopuses.
The team takes great care to meet each animal’s food and habitat needs and does its best to make their lives free from stress.
“We’ve sort of pioneered efforts to figure out what anesthesias are useful for cephalopods,” adds Rosenthal. “We’ve tried to be quite preemptive on this, in putting together what I think, in the US, is a one-of-a-kind policy for cephalopod research here.”