By Mark Davis
-
The Atlanta Journal-Constitution
Call
it a pipe dream, or — better — something cooked up in the imagination
of people who do implausible things with the very strands of life, DNA.Call it a last-chance grab at something fast vanishing. What is more fleeting than the genetic makeup of an endangered species?
Researchers at UGA’s Regenerative Bioscience Center want to create a Sumatran tiger and clouded leopard from skin cells harvested years ago from a tiger and leopard at Zoo Atlanta. By creating more big cats, they say, each species — one endangered, the other threatened — has a better chance of surviving.
Such a procedure is not unique. Researchers have used skin cells to create a pig, chickens and quail — but never something so large as a tiger or leopard.
Despite the tepid rate of donations, Dr. Franklin West, who proposed the cells-to-cats enterprise, remains upbeat. He has cells from Jalal, a Sumatran tiger, and Moby, a clouded leopard. Both were stars at Zoo Atlanta until their deaths several years ago. He’d like to see their genes passed on to future generations.
West is an assistant professor at the center. He specializes in cell-development research to help people suffering from strokes or traumatic brain injury. Working with cat cells, he said, is a sideline, “a labor of love.”
“It’s very exciting,” said West. “It’s doable”
West is working with Dr Steven Stice, the center’s director. Without going into exhaustive detail, they propose taking skin cells and using them to create stem cells. Stem cells are nature’s blank canvas: from them, other, more specialized cells can be created.
After creating stem cells, West wants to take his research a step further — making sperm from those cells. With that, he said, the engineered sperm of creatures that died years ago can be used to impregnate living cats. The genetic material of the tiger and leopard can be preserved in future animals. Gene pools in danger of depletion can be strengthened.
The danger is real. Panthera tigris sumatrae is the most endangered subspecies in the tiger family. An international animal conservation list notes that as few as 400 of the big cats may remain on the Indonesian island of Sumatra. Things are slightly better for Neofelis nebulosa, the clouded leopard. It’s suffered habitat loss in its traditional range, from Nepal to southern China, and is considered threatened.
Because they’re imperiled, the big cats’ genetic material is invaluable, West said. “As you can imagine,” he said, “skin cells from endangered species aren’t easy to find.”
‘Genetic legacy’
Jalal was born in 1993 at the Smithsonian’s National Zoo in Washington. Five years later, he came to Zoo Atlanta, where he sired a cub. He lived until 2010. Jalal was 16; for a tiger, that’s old.
Moby was born in 1996 at the Buffalo Zoo. He came to Zoo Atlanta nine years later, where he lived a solitary life — typical, for his species. He sired no offspring here. Moby died in 2013. Like his striped counterpart, he was 16.
Before dying, each gave up a sliver of flesh from his stomach. Veterinarians sedated each for a checkup, taking a slice of genetic material before winding up their examinations. West witnessed the examinations through a closed window. The sleeping cats’ sides rose and fell with slow, measured breaths. West marveled at their fearful symmetry. “They were beautiful,” he said.
The technology West proposes is intriguing but hardly guaranteed to work, said Budhan Pukazhenthi, who works at the Smithsonian’s Center for Species Survival. A physiologist, Pukazhenthi said such procedures don’t mean conservationists should give up traditional methods of species survival — chief among them, preserving animals’ natural habitats. “We are years and years down the road” from perfecting cells-to-sperm procedures, Pukazhenthi said. “There’s a lot more work that needs to be done.”
The proposed project excites Joe Mendelson, Zoo Atlanta’s director of research. “They (UGA scientists) are preserving the genetic legacy of individuals that have passed away,” said Mendelson. “That’s a remarkable contribution.”
Such research was hardly on the horizon when he became a scientist a quarter-century ago, Mendelson said. He only wishes better technology had been available in 2000, when Willie B, perhaps the zoo’s most famed resident, died. A statue of the gorilla on the zoo’s grounds is a bronze reminder of the big primate. “How important and fascinating would it be if we could breed Willie B into perpetuity?” he asked.
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