Thursday, May 1, 2014
FORT LAUDERDALE, Fla. (AP) — 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're 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 is beamed via satellite to a supercomputer at the University of Florida, which analyzes the results in a few hours and sends it back to the boat.
The work is part conservation.
"Life came from the oceans," Moroz says, bemoaning the extinction of species before scientists even catalog all of them. "We need a Manhattan Project for biodiversity. We're losing our heritage."
Surprising as it may sound, it's part brain science.
"We cannot regenerate our brain, our spinal cord or efficiently heal wounds without scars," Moroz notes.
But some simple sea creatures can.
Moroz accidentally cuts off part of a comb jelly's flowing lower lobe while putting it into a tank. A few hours later, the wound no longer is visible. By the next afternoon, that lobe had begun to regrow.
What's more remarkable, these gelatinous animals have neurons, or nerve cells, connected in circuitry that Moroz describes as an elementary brain. Injure those neural networks and some, but not all, species of comb jellies can regenerate them, too, in three days to five days, he says, if they're in a habitat where they can survive long enough.
"Nature has found solutions to how to stay healthy," says Moroz, who also studies human brains when he's back on shore. "We need to learn how they do it. But they are so fragile, we have to do it here," at sea.
Two trial-run sails off the Florida coast showed that the shipboard lab can work. Moroz's team generated information about thousands of genes in 22 organisms, including some rare comb jellies. Moroz's ultimate goal is to take the project around the world, to remote seas where it's especially hard to preserve marine animals for study.
"If the sea can't come to the lab, the lab must come to the sea," says Moroz, who invited The Associated Press on the second test trip, a 2½-day sail.
Flying fish zip alongside the 141-foot yacht Copasetic as it bounces across the giant ocean current known as the Gulf Stream. Inside the lab, a $50,000 genetic sequencer donated by Life Technologies is rocking on its special tabletop.
Molecular biologist Andrea Kohn wedges her hip against cabinets to stay upright, prepping the machine for the day's first run.
With a pipette in hand, she carefully drips precious samples from a comb jelly experiment onto a chip the size of a digital camera's memory card.
Graduate student Rachel Sanford had given a series of these animals a cut, and then biopsied the healing tissue 30 minutes, an hour and two hours later. She's trying to tease out what genetic activity spurs the steps of healing.
She studies the comb jellies' rudimentary brains in much the same way.
"I work on these things that are kind of like jellyfish, but they're not jellyfish at all. And I take out their brain. And then it grows back. And then I try to figure out how it grows back," is Sanford's simplified explanation.
She's looking for master regulators, key molecules that control that regrowth. If she can find some, a logical next step would be to investigate whether people harbor anything similar that might point to pathways important in spinal cord or brain injuries.
A clue, Moroz says, probably will be found in the differences between comb jelly species. "Why does one regenerate, and another not? That is the million-dollar question."
Evolution shows "there is more than one design for how to make a cell, how to make a brain," he adds.
The floating lab was born of frustration, Kohn says as she keeps close watch on the sequencing.
While there's been an earlier attempt at less complex DNA fingerprinting at sea, traditionally marine scientists collect animals, freeze samples and ship them home for genetic research.
But often, Moroz had shipments lost in transit or held up at U.S. Customs, thawed and ruined. Plus, some creatures' genetic material begins breaking down almost immediately after they're caught.
"When I think of all the animals we've lost through years and years," Kohn says, shaking her head. To completely map the genome of a single comb jelly species, "it took us a year to get DNA that wasn't degraded."
Researchers usually collect extra animals as insurance. But the supercomputer's rapid feedback means with Moroz's new project, "there's a lot more preservation," says University of Washington biology professor Billie Swalla, who is watching it with interest. "If you have unused animals, you can return them."
The pieces for the floating lab fell into place last fall after The International SeaKeepers Society introduced Moroz to University of Florida alumnus Steven Sablotsky, who was willing to lend his boat for the trial runs. Then, the Copasetic's captain noted that the main deck could fit a shipping container like freighters use to transport goods.
The nonprofit Florida Biodiversity Institute found one for sale, welded in windows and installed lab fixtures, and the team was off.
If oceanography and brains seem strange bedfellows, consider: Much of what scientists know about how human neurons and synapses, their connections, form memories came from years of studies using large sea slugs, called Aplysia, such as the one graduate student Emily Dabe gently cups in her hand.
Human brains have 86 billion neurons, give or take. Sea slugs have only about 10,000 neurons, large ones grouped into clusters rather than a central brain, Dabe explains while dissecting the easy-to-spot cells. She brought the animal on board as a control for experiments with the more mysterious creatures.
Yet scientists can condition sea slugs, with mild shocks to their gills, to study that type of memory, Dabe says. Her own research examines the neurochemical serotonin in the animals.
A bit further up the neural ladder, the octopus, with the most complex nervous systems of any animal without a backbone, has about 500 million neurons, says graduate student Gabrielle Winters. There are reports of them learning by watching, although Moroz cautions that's highly controversial.
Understanding how multiple genes work together to make increasingly complex memories is a building block toward better understanding of brain diseases. It requires working with simple creatures, notes the University of Washington's Swalla, an invertebrate specialist.
"We sequenced the human genome but we still don't know how it works," she explains. "To figure out how it works, you have to have other models you can work on. A lot of these genes are the same, and they interact in the same kind of pathways."
Moroz compares the genetic interactions to learning grammar: knowing an animal's, or a person's, DNA is like knowing the alphabet and some words, but not how they're strung together to make a sentence.
"We need to know how to orchestrate the grammar of the brain," said Moroz, whose research is funded by NASA, the National Institutes of Health, the National Science Foundation and others.
Outside on the deck, it's suddenly like Christmas.
Moroz and Gustav Paulay, a curator at the Florida Museum of Natural History, are back from a bluewater dive bearing gifts for the lab: clear jars and plastic bags teeming with invertebrates that Paulay describes as "wonky."
The race is on to keep them alive for study. Moroz's three graduate students hoist buckets of seawater and transfer the delicate animals into tanks, stopping to ogle strange finds.
"Oh my god, you have to see this one," Paulay exclaims, entranced by a rarely seen type of flat, see-through snail, pink ribbons snaking through its shell-free body.
Another transparent mollusk has wings.
Then there's the wriggly worm that looks like a Chinese dragon, big eyes glowing red under the microscope. Unlike with most worms, these eyes actually form images, Paulay instructs as the ship's crew and passengers crowd around to watch.
Invertebrates are critical to the food chain, but little is known about them. It's estimated that thousands of species have yet to be identified. Paulay calls them "nature's master works," but says they're just not as sexy to study as, say, pandas or tigers.
In the oceans, "the amount of new stuff out there is boggling. It's changing before our eyes," he says.
But the catch of this day is the collection of comb jellies, officially named ctenophores. (Don't pronounce the silent "c''.) They made headlines last year as DNA research suggested these animals may represent the oldest branch of the animal family tree, rather than the sea sponges that scientists long have believed held that distinction.
Named for the comb-like rows of hair they use to swim, the ctenophores refract light so it looks like they flash electric through the water. The one that shimmered like an opal is a little bigger than a golf ball.
Another is light pink, flat and shaped like a delicate sack. This one's a hungry predator: It swallows whole its larger, rounded cousin when the researchers turn their backs.
A tiny, hot pink version zips through the water — it looks like a new species, Moroz says.
Some ctenophores regenerate that elementary brain and some, like that hungry sack-shaped Beroe, 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?"