1st Clone Of US Endangered Species, A Ferret, Announced
Scientists have cloned the first U.S. endangered species, a black-footed ferret duplicated from the genes of an animal that died over 30 years ago.
The slinky predator named Elizabeth Ann, born Dec. 10 and announced Thursday, is cute as a button. But watch out — unlike the domestic ferret foster mom who carried her into the world, she's wild at heart.
"You might have been handling a black-footed ferret kit and then they try to take your finger off the next day," U.S. Fish and Wildlife Service black-footed ferret recovery coordinator Pete Gober said Thursday. “She's holding her own.”
Elizabeth Ann was born and is being raised at a Fish and Wildlife Service black-footed ferret breeding facility in Fort Collins, Colorado. She's a genetic copy of a ferret named Willa who died in 1988 and whose remains were frozen in the early days of DNA technology.
Cloning eventually could bring back extinct species such as the passenger pigeon. For now, the technique holds promise for helping endangered species including a Mongolian wild horse that was cloned and last summer born at a Texas facility.
“Biotechnology and genomic data can really make a difference on the ground with conservation efforts,” said Ben Novak, lead scientist with Revive & Restore, a biotechnology-focused conservation nonprofit that coordinated the ferret and horse clonings.
Black-footed ferrets are a type of weasel easily recognized by dark eye markings resembling a robber's mask. Charismatic and nocturnal, they feed exclusively on prairie dogs while living in the midst of the rodents' sometimes vast burrow colonies.
Even before cloning, black-footed ferrets were a conservation success story. They were thought extinct — victims of habitat loss as ranchers shot and poisoned off prairie dog colonies that made rangelands less suitable for cattle — until a ranch dog named Shep brought a dead one home in Wyoming in 1981.
Scientists gathered the remaining population for a captive breeding program that has released thousands of ferrets at dozens of sites in the western U.S., Canada and Mexico since the 1990s.
Lack of genetic diversity prevents an ongoing risk. All ferrets reintroduced so far are the descendants of just seven closely related animals — genetic similarity that makes today's ferrets potentially susceptible to intestinal parasites and diseases such as sylvatic plague.
Willa could have passed along her genes the usual way, too, but a male born to her named Cody “didn't do his job" and her lineage died out, said Gober.
When Willa died, the Wyoming Game and Fish Department sent her tissues to a “frozen zoo” run by San Diego Zoo Global that maintains cells from more than 1,100 species and subspecies worldwide. Eventually, scientists may be able to modify those genes to help cloned animals survive.
“This is not the endpoint to clone this animal. This is the beginning of the exploration about using this technology to bolster and sustain the genetic diversity of a population,” said Oliver Ryder, a geneticist at San Diego Zoo Global.
He helps manage the nitrogen-cooled repository that stored a skin biopsy from Willa for more than 30 years. That simple sample generated enough living tissue to clone the ferret, which is also known as the American polecat.
"The black-footed ferret population has spent 30 years in captivity and has lost genetic variation," Ryder said. "This type of approach means that we don't have to lose any more genetic variation."
Ryder said this work may just be useful for efforts to revive other endangered species.
“With these cloning techniques, you can basically freeze time and regenerate those cells,” Gober said. “We’re far from it now as far as tinkering with the genome to confer any genetic resistance, but that’s a possibility in the future.”
Cloning makes a new plant or animal by copying the genes of an existing animal. Texas-based Viagen, a company that clones pet cats for $35,000 and dogs for $50,000, cloned a Przewalski’s horse, a wild horse species from Mongolia born last summer.
Similar to the black-footed ferret, the 2,000 or so surviving Przewalski's horses are descendants of just a dozen animals.
Viagen also cloned Willa through coordination by Revive & Restore, a wildlife conservation organization focused on biotechnology. Besides cloning, the nonprofit in Sausalito, California, promotes genetic research into imperiled life forms ranging from sea stars to jaguars.
“How can we actually apply some of those advances in science for conservation? Because conservation needs more tools in the toolbox. That's our whole motivation. Cloning is just one of the tools,” said Revive & Restore co-founder and executive director Ryan Phelan.
Elizabeth Ann was born to a tame domestic ferret, which avoided putting a rare black-footed ferret at risk. Two unrelated domestic ferrets also were born by cesarian section; a second clone didn’t survive.
Elizabeth Ann and future clones of Willa will form a new line of black-footed ferrets that will remain in Fort Collins for study. There currently are no plans to release them into the wild, said Gober.
Novak, the lead scientist at Revive & Restore, calls himself the group's “passenger pigeon guy” for his work to someday bring back the once common bird that has been extinct for over a century. Cloning birds is considered far more challenging than mammals because of their eggs, yet the group's projects even include trying to bring back a woolly mammoth, a creature extinct for thousands of years.
The seven-year effort to clone a black-footed ferret was far less theoretical, he said, and shows how biotechnology can help conservation now. In December, Novak loaded up a camper and drove to Fort Collins with his family to see the results firsthand.
“I absolutely had to see our beautiful clone in person,” Novak said. "There’s just nothing more incredible than that.”