Scientists harness the chemistry of sea creatures that produce their own light for biomedical research.

By Susanne Bard

Some animals, like jellyfish and fireflies, produce their own light. Scientists have harnessed these properties in the service of biomedical research. Now, Scripps Institution of Oceanography researchers have unscrambled the unique chemistry of another glowing creature – a marine worm.

Divers in coastal waters may be surprised by a brilliant blue glow on the seafloor. The light is produced by the Chaetopterus parchment worm, which lives inside small brown tubes, secreting bioluminescent mucus when disturbed, according to Scripps Institution of Oceanography marine biologist Dimitri Deheyn.

“As a diver, if you press on those tubes, you will suddenly see this bluish mucus that will spew out of those tubes, and that comes from the worm,” Deheyn says. “The worm produces a blue bioluminescence, which is also magical, and as it diffuses out in the water you see this cloud of blue light.” Deheyn believes the light may be a defense mechanism, warning away would-be predators like fish. “The mucus might stick to the fish, and maybe one of its own predators will say, ‘here is a fish that is totally lit up for me to eat.’”

In nature, bioluminescence is created by a reaction between two chemicals. “Animals that produce light have tiny, itty bitty glow sticks in their cells,” jokes Deheyn. “The light is produced by an enzyme called a luciferase, and a compound called a luciferin, and the enzyme will react with the luciferin, and it’s only once those two are mixed together they will charge each other. And because nature says that you cannot be in an unstable state, molecules will try to go back to their basic energy level.” In doing so, they produce light.

Deheyn says most bioluminescent invertebrates, like fireflies, produce this light only briefly. But what’s unusual about the Chaetopterus parchment worm is that it can glow for up to 27 hours at a time. “Most light-producing organisms produce short flashes,” says Deheyn. “Very few have long glows. Mushrooms do glow, some bacteria, but otherwise invertebrates do not glow.”

Deheyn’s lab is deciphering the specific chemistry behind the parchment worm’s long-lasting glow. A paper in the journal Photochemistry and Photobiology outlines their discoveries. “The worm uses a chemical reaction that does not follow the conventional chemistries. ” So far, they’ve identified riboflavin, a B vitamin, and the protein ferritin as important players in the light production. By understanding its unique biochemistry, the researchers hope to recreate the worm’s bioluminescent properties in the lab. “Ultimately, we want to regenerate light in the laboratory, we want to be able to have it in a test tube,” he says. Once they accomplish that goal, the worm-inspired bioluminescence could be useful in biomedical research — as a new way to visualize gene activity.

Learn more about parchment worm chemistry.

Listen to the AAAS Science Update podcast version of this story, written and co-hosted by Susanne Bard.