Wanted: virile but gentle companion for America’s first cloned skunk | Cloning


Elizabeth Ann is about to make history. The world’s first cloned black-footed ferret has just celebrated its first birthday and has reached an age where it can start breeding. And, if she succeeds and produces healthy kits, the little predator will give a valuable boost to attempts to save her critically endangered species.

However, scientists acknowledge that they will need to be extremely careful when selecting possible mates for Elizabeth Ann, who is being held at a conservation center near Fort Collins, Colorado. In particular, the male they end up selecting must display one essential quality, they say: he must be gentle.

American polecat (Mustella nigripes) is not known for its mild temperament. Elizabeth Ann growls at guards who get too close, for example. However, the species desperately needs an injection of fresh genes and Elizabeth Ann can provide them – as long as it survives the breeding encounter, scientists say.

“When it comes to black-footed ferrets, the mating scenario can get a bit difficult and we don’t want Elizabeth Ann to get hurt. She’s precious,” said Oliver Ryder, director of genetic conservation at the zoo. from San Diego. Observer.

“So we need an experienced male who has already produced offspring and therefore will not be sterile – a problem that affects many male black-footed ferrets today. In addition, we will select him for his sweetness,” added Ryder, who clarified that the choice of a partner for Elizabeth Ann was now “imminent”.

Dolly the cloned sheep. Photograph: Murdo MacLeod/The Guardian

The black-footed ferret is a grumpy, slender predator 60 cm long with black markings on the face, legs and tail. It once inhabited large swaths of the Great Plains of the United States, living off a menu consisting primarily of prairie dogs, which are a type of ground squirrel. However, it was wiped out when agriculture spread to the central United States, and by the 1970s it was thought to be extinct.

Then one night in 1981, Wyoming rancher John Hogg heard strange noises on his land and discovered a colony of black-footed ferrets. Wildlife biologists flocked to the ranch and have since used its animals to establish a ferret breeding program in an effort to reestablish colonies in the United States.

However, only seven of the ferrets found on Hogg Ranch were able to breed. As a result, the blackfoot population is highly inbred, with each animal having a relatedness to the others that falls between that of a brother and a first cousin. Damaging mutations now affect the breeding population.

An injection of fresh ferret genes is absolutely necessary, and they can be provided by Elizabeth Ann. She is the product of tissue that had been taken from a female black-footed ferret named Willa decades ago. His cells were kept at San Diego’s Frozen Zoo, a storage facility where genetic material – DNA, sperm, eggs, embryos and living tissue – from endangered animals is stored in liquid nitrogen.

A few years ago it was decided to use the same technology used in Scotland to create Dolly the Sheep in 1996 to produce a clone of Willa. His cells were used to generate embryos which were implanted into three pet ferrets. Two of the pregnancies failed, while the third surrogate had a stillborn child…and Elizabeth Ann, who now thrives on a diet of hamsters in her Colorado home.

Crucially, his DNA contains different versions of the genes that predominate among inbred ferrets in the breeding program, which raised hopes that his offspring could significantly improve the genetic viability of black-footed ferrets. As Ryder says, “Elizabeth Ann is a treasure trove of genetic diversity as far as we’re concerned.”

Additionally, plans are underway to create another batch of cloned Black-footed Ferrets – with the same goal: to increase the species’ genetic diversity and halt its reproductive decline. “That’s the heart of the effort here,” Ryder said. “Can Elizabeth Ann pass her genes on to descending generations of black-footed ferrets?”

Elizabeth Ann’s story has important implications for all endangered species, Ryder added. “We should now be storing cells from all kinds of endangered animals, because we are losing biodiversity and wild animal gene pools are shrinking. At least if we have the cells, we could, at least future, to do for other species what we hope to do for the black-footed ferret with Elizabeth Ann.


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