Scientists have successfully cloned an en.d.anger.ed black-footed ferret, using preserved cells from a long-d.e a.d wild animal. This is the first time any native en.d.anger.ed species has been cloned in the United States.
The advance is a milestone for the conservation of black-footed ferrets, North America’s only native ferret. This species was once found over vast swathes of the American West, but they dwindled as farmers and ranchers el.im.ina.ted their primary prey, prairie dogs. By the 1970s they were thought to be ex.t.in.ct. Then, in 1981, a ranch dog led scientists to a colony of 18 on a property in Wyoming.
Those survivors became the basis of a captive-breeding program managed in part by the U.S. Fish and Wildlife Service in Colorado, and the animals have since been reintroduced to eight states in the Great Plains. But only seven of the original wild animals bred, and all living ferrets are closely related. Their wild population today is roughly 400 to 500, says Pete Gober, black-footed ferret recovery coordinator for the service.
The pre.dat.or named Elizabeth Ann, born Dec. 10 and announced Thursday. She 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 d.i e.d in 1988 and whose remains were frozen in the early days of DNA technology. She has no living descendants. 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 d.i e.d out, said Gober. Her cells have been cryopreserved at the Frozen Zoo, a program of San Diego Zoo Global that has collected samples from some 1,100 rare and en.d.anger.ed species worldwide. Researchers hope to breed Elizabeth Ann and introduce her offspring into the wild to inject much-needed genetic diversity into the population. For now, the technique holds promise for helping en.d.anger.ed species including a Mongolian wild horse that was cloned and last summer born at a Texas facility.
The cloning process began by taking eggs from sedated domestic ferrets, a related species, which were used to avoid putting en.d.anger.ed female black-footed ferrets at r.is.k. The eggs were matured, and scientists with ViaGen used pipettes to remove the nucleus and genetic material from them, Walker says. After transferring the contents of Willa’s cells into each egg, scientists gave them an activation stimulus—basically an electric charge—to get them to divide, Walker says. This created embryos that were then implanted into a domestic ferret. One of them took.
It’s essentially the same process used in Dolly the sheep 25 years ago, the first mammal cloned from an adult cell—although it’s slightly more complicated as it involves transferring genetic material from one species into another.
Elizabeth Ann was born to a tame domestic ferret, which avoided putting a rare black-footed ferret at r.is.k. 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.
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.