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Living cell library grows at USM ; Scientists will be able to study marine creatures too large for the lab.

Posted on: Sunday, 15 February 2004, 06:00 CST

Scientists at the University of Southern Maine are building a new national library of living cells collected from the lungs, kidneys, brains and other organs of marine mammals.

The National Marine Cell Line Library will make it easier for researchers to study whales, seals, sea lions, dolphins and other marine creatures that are federally protected and too large to bring into a landlocked laboratory.

By exposing the cells to viruses, toxins and other pollutants, marine scientists can better understand their effects on the animals and begin to prioritize the threats in the sea.

Cells taken from the endangered Steller sea lion, for example, are being used to examine whether toxic metals are impairing their ability to reproduce.

The cell lines can also be used to diagnose illnesses and to conduct comparative studies, including comparisons between marine mammals and humans. The bowhead whale in the Arctic, for example, doesn't seem to get cancer.

"These guys live 150 to 200 years," said John Wise, director of the Wise Laboratory of Environmental and Genetic Toxicology at USM. "They bioaccumulate very high levels of metals, and they don't appear to get cancer. They've done necropsies on 400 animals, and they've never found any tumors."

Although scientists see huge research potential, a single animal can be 50 feet long and weigh 200,000 pounds. "You clearly can't bring these guys into the laboratory," said Wise.

Wise was a professor at Yale, studying how metals cause cancer in humans, when he stumbled into marine science. One of his graduate students was interested in doing some work in Alaska, examining how metals move up the food chain.

After a little research, Wise became intrigued by the fact that bowhead whales don't get cancer and asked a NASA researcher who was collecting and culturing their cells for a sample. He decided it would be ideal to have cells from a whale that does get cancer, too, so he called the Mystic Aquarium in Mystic, Conn., and asked for a tissue sample from one of its beluga whales.

An aquarium scientist asked if Wise would be interested in collecting and growing cells from other marine mammal species, and that began a partnership that led to the creation of the cell line library.

The collection of marine mammal cell lines is still in its infancy, but promises to be a valuable tool for researchers around the world. Before this project got under way, the cells were haphazardly collected and not generally shared among scientists. Wise said it was tough to find some initial funding.

"You're building a tool, you're not answering a question," he said. "Places don't like to fund building tools, they like to fund unanswered questions."

Yet access to marine cell lines is one of the things that's most needed for certain kinds of marine research.

J. Lawrence Dunn, staff veterinarian at the Mystic Aquarium, said he attended a meeting in Alaska just three weeks ago where scientists were discussing the possibility of disease as the cause of a drop in Steller sea lion populations. At a workshop one day, they discussed what was needed to improve research on the topic.

"One thing that came up consistently was we need cell lines to work with because there's lots of work that you can't do on live animals for either logistic purposes or because these are endangered species," Dunn said. "Having access to the cell line gives you a model that hopefully will represent what happens in the living animal without putting any stress on the population of living animals."

The tissue used to develop the National Marine Cell Line Library comes from the lungs, liver, kidneys, testes, ovaries, brain, skin, spleen, heart and eye. The tissue is collected from the organs of stranded animals and is donated by a network of collaborators, including the Mystic Aquarium and the Marine Mammal Center in Sausalito, Calif.

Other tissue comes from the federally authorized native hunt for bowhead whales in Barrow, Alaska, the northernmost city in the United States. Sandra Wise, a research associate in the USM lab who is married to John Wise, travels to Barrow every year to collect whatever tissue she can from the organs of whales killed in the hunt.

"It's a pretty amazing trip," she said. "The first year we were totally unprepared for what it's like up there."

Located more than 300 miles above the Arctic Circle, Barrow is a harsh arctic environment where locals carry shotguns to defend themselves from polar bears. The Inupiat Eskimo community there hunts bowhead whales twice a year from vessels that look something like lobster boats. When they spot a whale, they radio the sighting in to those waiting on shore, and once there's a strike, they say a prayer in their native language.

"Everybody in the town has a radio, too, and they get on the radio and say 'Congratulations and God bless,' " Sandra Wise said.

The whale is towed in as close as possible to the beach, a tractor pulls it on shore, and then a forklift carries it to the site where it is to be butchered.

Anyone who works with marine mammals must have a federal permit, and Wise's permit does not allow her to cut into the animal, so the wildlife officials collect tissue for her. "We're only allowed to accept and receive," she said.

Eskimos use and eat a lot of the whale's tissues - the kidney is used in Christmas celebrations - so she is careful to take only what is offered.

The tissue samples are brought back to Portland in liquid nitrogen day shippers.

Generally, all the lab needs from, say, a whale lung is a sample of tissue the size of a silver dollar. But it's not always that simple. For example, a whale's entire liver - the size of a UPS truck - must be flushed with water before yielding a tissue sample.

Once the cells arrive back at the lab, they are grown in culture and multiply rapidly. The cells are then genetically manipulated to "immortalize" them so they become permanent cell lines. Liquid nitrogen keeps them suspended in time until a researcher is ready to use them.

So far the lab has created about 150 different cell lines from 18 different species. The goal for each species is to have cell lines from at least one male and one female representing three different age classes - juvenile, subadult and adult.

There is still an experimental aspect to the work because all of the tools used to grow the cells have been used so far only in humans and rodents.

Researchers who want to use the cell lines must apply through the Mystic Aquarium, which handles their distribution. A scientific review panel considers each request, ensuring the applicant has the proper federal permits and isn't duplicating work.

Wise's lab is using the cells for its Steller sea lion project, funded by the National Oceanic and Atmospheric Administration. In that project, Wise is trying to determine whether exposure to toxic metals is responsible for the crash in the sea lion population, perhaps by impairing their ability to reproduce.

"We look for some kind of DNA-damaging effect, and then figure out what's the concentration of metal inside the cell that causes that DNA damage effect," he said. "And then we get tissues from the wild animals, figure out what the metal content is in the cell of that tissue, and see if they line up."

Cleaning up all the toxic metals and other pollutants in the sea would be too expensive, Wise said, but the sea lion work along with other such studies could help scientists figure out which contaminants are doing the most damage.

"You could prioritize and say, 'these five are extremely bad, let's get rid of those,' "he said.

The lab received two new grants from NOAA last fall, one to fund the creation of cell lines using tissues from stranded animals, the other for a study that will use the bowhead whale as a model to study the endangered right whale.

"Northern right whales and bowheads are the only two species in their family, so they're each other's closest relative," Wise said. "When right whales die, by the time somebody comes across the body the tissues are so damaged you can't use them."

Right whale researchers are donating collected skin so that Wise can compare it to bowhead whale skin. He's hoping to use the information to figure out how to create models of right whales' other organs.

That's important because substances that are not toxic to the whales' skin may be doing significant damage to its internal organs.

"The habit is just to dart, and darting actually will tell you very little about the toxic effects," Wise said. "Mammals don't accumulate (toxins) in blood or skin, they accumulate it in their organs. So darting has its values, but we need more."

Staff Writer Meredith Goad can be contacted at 791-6332 or at:

mgoad@pressherald.com

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