Scientists study fast-healing comb jellies

Floating lab finds ‘aliens of the sea’


Researcher Leonid Moroz emerges from a dive off the Florida Keys and gleefully displays a plastic bag holding a creature that shimmers like an opal in the seawater.

This translucent animal and its similarly strange cousins are food for science. They regrow with amazing speed if they get chopped up. Some even regenerate a rudimentary brain.

“Meet the aliens of the sea,” the neurobiologist at the University of Florida says with a huge grin. They are headed for his unique floating laboratory.

Moroz is on a quest to decode the genomic blueprints of fragile marine life, like these mysterious comb jellies, in real time — on board the ship where they were caught — so he can learn which genes switch on and off as the animals perform such tasks as regeneration.

No white coats needed here. The lab is a specially retrofitted steel shipping container, able to be lifted by crane onto any ship Moroz can recruit for a scientific adventure. Inside, researchers in flip-flops operate a state-of-the-art genomic sequencing machine secured to a tilting tabletop that bobs with rough waves. Genetic data are beamed via satellite to a supercomputer at the University of Florida, which analyzes the results in a few hours and sends them back.

The work is part conservation. “Life came from the oceans,” Moroz said, bemoaning the extinction of species before scientists even catalog all of them.

Surprising as it may sound, it is part brain science. “We cannot regenerate our brain, our spinal cord or efficiently heal wounds without scars,” Moroz noted. But some simple sea creatures can. Moroz accidentally cut off part of a comb jelly’s flowing lower lobe. By the next afternoon, it had begun to regrow.

What is more remarkable, these gelatinous animals have neurons connected in circuitry that Moroz describes as an elementary brain. Injure those neural networks and some but not all jelly species can regenerate them in three days to five days, he said.

“We need to learn how they do it. But they are so fragile, we have to do it here” at sea, he said.

In two trial sails off the coast of Florida, Moroz’s team generated information about thousands of genes in 22 organisms. Moroz’s ultimate goal is to take the project around the world, to remote seas where it is especially hard to preserve marine animals for study.

“If the sea can’t come to the lab, the lab must come to the sea,” said Moroz.

In the lab, one graduate student has cut some of these animals and then biopsied the healing tissue 30 minutes, an hour and two hours later. She studies the comb jellies’ rudimentary brains in much the same way, looking for master regulators, key molecules that control regrowth. If she can find some, a logical next question is whether people harbor anything similar that might point to pathways important in spinal cord or brain injuries.

The lab was born of frustration after Moroz kept shipping samples home that arrived too degraded for genetic research. The pieces fell into place when a University of Florida alumnus lent the team his boat for the trial runs. Then the Copasetic’s captain noted that a shipping container like those used by freighters would fit on the main deck.

The nonprofit Florida Biodiversity Institute found one for sale, welded in windows and installed lab fixtures.

Oceanography and brains may seem to be strange bedfellows. But much of what scientists know about how human neurons form memories came from studying large green sea slugs.

Human brains have 86 billion neurons, give or take. Sea slugs have only about 10,000 large neurons grouped into clusters rather than a central brain.

Yet scientists can condition sea slugs, with mild shocks, to study that type of memory.

A bit further up the neural ladder, the octopus has about 500 million neurons. There are reports of them learning by watching, although Moroz cautions that is highly controversial.

The question is how multiple genes work together for increasingly complex memories. That requires working with simple creatures, which share certain genetic pathways with people, said University of Washington biology professor Billie Swalla, who is watching Moroz’s project with interest.

Moroz compares the genetic interactions to learning grammar. Knowing DNA is like knowing the alphabet and some words, but not how they are strung together to make a sentence. “We need to know how to orchestrate the grammar of the brain,” he said.

Then there are the comb jellies, officially called ctenophores, which refract light so it looks like they flash electric through the water. Some ctenophores regenerate that elementary brain and some don’t. Some use more muscles to swim. Some have tentacles to catch their food instead of the Beroe’s stretchy mouth.

Moroz muses on the diversity: “Tell me honestly, why do we study rats?”