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Scientists are finding out how to genetically alter an octopus: Missiles



On the left is the unmodified hatchery of coastal octopuses (Doryteuthis pealeii). One of them was injected with CRISPR-Cas9 targeting the pigment gene before the first cell division. It has very few pigmented cells and brighter eyes.

Karen Crawford


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Karen Crawford

The first genetically modified octopus scientists have been fascinated by a possible new way of studying marine animals, which are so strange that they have sometimes compared them to extraterrestrial life forms.

Researchers say this week that they have banned a gene for pigmentation in the so-called octopus Doryteuthis pealeiiTheir success shows that cephalopods ̵

1; including octopuses and octopuses – can finally be studied using the same types of genetic tools that have allowed scientists to study the biology of known laboratory animals such as mice and fruit flies. These are easy to maintain in the laboratory, and scientists routinely modify their genes to obtain information about behaviors, diseases, and possible treatments.

Cephalopods can seem quite strange without scientists playing with their genes. These tentacle creatures have huge, clever brains that don’t look like our own. They travel by jet propulsion and some can change skin color in a flash. This whole peculiarity is exactly why some biologists want to understand them better.

“These big brains and this sophistication of behavior developed completely independently,” says Joshua Rosenthal, a researcher at the Marine Biological Laboratory in Woods Hole, Massachusetts. “This provides an opportunity to compare them with us and find out which elements are common and which elements are unique.”

Until now, cephalopod research has been limited by the fact that there is no way to manipulate squid or octopus genes. Rosenthal is part of a group that is trying to change everything. The team raises a wide range of exotic cephalopod species – everything from showy cuttlefish to dwarf squid – to find out how to keep them captive and change their DNA.

Scientists are also working with the famous local octopus, which lives in the waters around Woods Hole. Historically, this octopus has been important to neurobiologists because it has a huge, easily studying nerve cell. Much of what is known about how nerve cells send electrical signals comes from studies of this cell, and research led to the Nobel Prize in 1963. Scientists sequenced the DNA that forms the genetic code of this octopus.

Every summer, a research ship comes out of Woods Hole and collects squid, Doryteuthis pealeiiKaren Crawford of Maryland College in Maryland, a key member of the research team, previously figured out how to remove sperm and eggs from this octopus and how to produce embryos in the laboratory.

Studies on the Internet Doryteuthis pealeii octopus, shown above, led to great advances in neurobiology.

Roger T. Hanlon / https: //urldefense.com/v3/__http: //www.mbl.edu/bell/current-faculty/hanlon/__ .; !!


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Roger T. Hanlon / https: //urldefense.com/v3/__http: //www.mbl.edu/bell/current-faculty/hanlon/__ .; !!

Studies on the Internet Doryteuthis pealeii octopus, shown above, led to great advances in neurobiology.

Roger T. Hanlon / https: //urldefense.com/v3/__http: //www.mbl.edu/bell/current-faculty/hanlon/__ .; !!

Based on this work, she and her colleagues found out how to inject gene-altering materials into a fertilized egg, how to break down a gene involved in the coloring of squid skin and eye cells. The biggest challenge was to get through the hard outer layer that surrounded the early squid, says Rosenthal.

“We should break needles for months,” he says. “Finally, we came up with a way to get a hypodermic needle. That turned out to be one of the biggest obstacles in this study. “

The resulting octopuses had much less small dark spots, which are normally characteristic of the species, because the pigment gene was discarded in almost every cell.

“It simply came to our notice then. I would like to understand how these animals work from a molecular level, so now we actually have the opportunity to go and test what an individual gene does, ”says Carrie Albertin, another member of the research team who also works in the marine biological laboratory.

“This is honestly, if you asked me five years ago if we could do it, I just giggled and said, ‘I’m dreaming about it. “But, you know, I didn’t think it would be possible. And yet we are here, “says Albertin.

these Doryteuthis pealeii octopuses were injected with CRISPR-Cas9 at different times before the first cell division, resulting in mosaic embryos with different characteristics.

Karen Crawford


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Karen Crawford

This particular species of squid cannot be brought to adulthood in the laboratory – it is too large. However, there are many other, smaller octopuses and octopuses, and the team is already working to transfer technology to those that grow in captivity. Scientists also prefer to add genes than just eliminate existing ones.

The work thrilled other octopus biologists, such as Sarah McAnulty of the University of Connecticut. She studied Hawaiian squid and claims that scientists have tried to genetically alter cephalopods in the past.

“It’s incredibly impressive that it works, and it’s a huge advance for cephalopod researchers around the world,” says McAnulty. “We should all throw bottles of champagne. That’s wonderful.”

Twisted tentacle of a coastal octopus longfin, D. pealeii.

Karen Crawford


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Twisted tentacle of a coastal octopus longfin, D. pealeii.

Karen Crawford

When biologists study natural squid, they eventually “hit a wall of understanding” because they can’t play with animal genetics to examine how its systems work at the most basic level, McAnulty says. He believes that the ability to genetically modify cephalopods should allow for all kinds of new experiments.

“If I could do anything, I would start playing with the octopus’s immune system altogether,” says McAnulty, trying to figure out how, for example, the Hawaiian bobtail octopus knows it won’t attack the kind of glowing symbiotic bacteria that lives in it. .


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