We Should Study Octopus DNA To Better Understand Our Own

If you ask Carrie Albertin why she studies octopuses, she inevitably arrives at how awesome and strange they are. When she was interviewing for graduate school at the University of Chicago, where she just finished her doctorate, her advisor had recently started a project with octopuses.

"In this 250 gallon tank, there's one tiny little octopus that, as we were watching, hatched out, looked at us, inked, and swam away. I was sold—they are the most bizarre animals," Albertin told Motherboard.

There are good scientific reasons to study them, too. Octopuses and other cephalopods like squid seem fundamentally dissimilar from humans—they lack spines and warm blood but have three hearts. But elements of their biology can help scientists better understand our own, and help us treat diseases in the nervous system or our genes.

Studying the genomes of cephalopods is a recent endeavor. Octopuses were the first cephalopod species to have their DNA sequenced, and that was only in 2015. That work has revealed some surprising results.

Cephalopods, for example, are able to edit their own RNA, code copied from DNA that provide instructions for how to build the proteins that allow each organism to function. That unique ability allows cephalopods to create a range of proteins from the same DNA, which could help these cold-blooded animals function more easily in habitats that vary in temperature.

"Some researchers have proposed using this editing mechanism to possibly go through and change genetic sequences [that can cause disease]," Albertin said. Of course, that's way far off in the future, "but these are the kinds of insights into biology that can give us a whole new set of tools."

She made this case on Tuesday at the GP-write meeting in New York City, where 200 prominent geneticists, biologists, and ethicists got together to talk about how to create the first synthetic genome, first in for simple organisms and eventually synthesizing a human genome. This project is a big push for basic research, the kind of stuff that gives us tools like CRISPR with nearly limitless applications in fields as diverse as medicine, agriculture, and data storage.

There's another compelling reason to study cephalopods: They offer certain similarities to humans not found in the organisms traditionally used in basic biology, like mice and fruit flies.

There's a family of proteins called protocadherins, found in neurons, that keep parts of the neurons from sticking to themselves and ensure that neurons form functional circuits. Protocadherins were first discovered in vertebrates. The more genes that code for protocadherins, the theory goes, the more complex the nervous system. Humans and mice both have more than 50 genes that code for protocadherins. Fruit flies don't have any, although they have proteins that function the same way; C. elegans, the nematode often studied in basic research, has none.

Meanwhile, octopuses have 168 genes. That may read like a small number in the context of octopuses' 34,000 or so genes, but that's three times as many of these types of genes as humans, a testament to the sophistication of their nervous systems. This is likely an example of convergent evolution—vertebrates and cephalopods branched off long ago, yet they both developed the same way to create complex nervous systems.

Studying cephalopods might reveal more about the basic functions of nervous systems, including our own, which in the future could help researchers figure out better treatments for conditions that affect it, such as Parkinson's, multiple sclerosis, and pain conditions.

Albertin presented at GP-write because she thinks the octopus merits more basic research which can lead to the development of scientific tools their their original discoverers couldn't have imagined. "CRISPR, synthetic biology—all these new technologies started as a boutique interest. Once you figure out how to apply it, all of a sudden it opens up a whole new world," Albertin said.

Albertin is convinced that octopuses and other cephalopods have a lot more they can reveal to us. "Science is about being excited about questions. And it's hard not to get excited about these guys."

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