Cloning of black-footed ferrets from cryopreserved tissue

The US Fish and Wildlife Service (FWS) announced that scientists have successfully cloned two black-footed ferrets from frozen tissue samples.

This is the second and third cloned individual of the black-footed ferret, after the first individual was cloned and born in December 2020.

Black-footed ferrets are an endangered species and scientists hope these new clones will help increase the species' genetic diversity.

The limited genetic diversity of the current black-footed ferret population makes them susceptible to diseases and genetic defects, while also reducing their reproductive rates, hindering their ability to adapt to the wild environment, making it difficult for them to adapt to the wild. for quantity recovery.

Noreen, one of two black-footed ferrets recently born by cloning (Photo: Rohan Patel).

" Genetic diversity is important for resilience to environmental changes ," said Megan Owen, vice president of conservation science at the San Diego Zoo, which is involved in the cloning effort. asexual black-footed ferrets, shared. "Basically, this is considered the raw material of adaptive evolution."

The two new cloned individuals are named Noreen and Antonia. Currently, these two individuals are in good health, achieving developmental and behavioral milestones as expected by scientists.

Noreen was born at the National Black-footed Ferret Conservation Center in Colorado, while Antonia was born at the Smithsonian National Zoo and Conservation Biology Institute in Washington, D.C.

Black-footed ferrets are animals native to North America, having lived on this continent for at least 100,000 years. They have long, slender bodies with light-colored fur, but their faces, four legs and tail are black. This is a nocturnal mammal that burrows underground for shelter.

An estimated 500,000 to 1 million black-footed ferrets lived in the 1800s, ranging from northern Mexico to southern Canada. However, in the 20th century, the population of black-footed ferrets decreased sharply as farmers exterminated marmots, which destroyed crops and were a food source for black-footed ferrets. In addition, a number of diseases have also seriously reduced the number of black-footed ferrets.

Scientists once thought that the black-footed ferret became extinct in 1979, but in 1981, an American farmer's hunting dog brought home the morgue of a black-footed ferret. Scientists recently began researching and found a small population of this species near the town of Meeteetse, Wyoming.

In the following years, scientists captured seven black-footed ferrets and began a program to breed the animals for conservation. After breeding in captivity, scientists returned them to the wild at 34 locations across the United States, Canada and Mexico. FWS estimates there are currently several hundred black-footed ferrets living in the wild.

However, this conservation process encounters a problem, which is that almost all black-footed ferrets living in the wild are descendants of 7 ferrets that were previously captured in the wild, this has severely limited their genetic diversity.

But the three black-footed ferrets born by cloning are different. They were cloned from tissue samples frozen in 1988 of a black-footed ferret named WIlla. This tissue sample is stored at the San Diego Wildlife Alliance Cryogenic Bank.

Willa's special feature is that it has never reproduced, meaning its genes have never been passed on to future generations.

To clone a black-footed ferret, scientists injected a cell from Willa into the egg of a domesticated black-footed ferret.

The first cloned black-footed ferret was born at the end of 2020 and was named Elizabeth Ann. This is a female individual, currently being cared for at the National Black-footed Ferret Conservation Center in good health, however, this ferret cannot reproduce due to ovarian mutation.

According to FWS, because ovarian mutations are also common in other black-footed ferrets, researchers do not believe this condition is related to the cloning process.

After Noreen and Antonia, two newly cloned black-footed ferrets, mature, scientists will try to breed them to increase genetic diversity for the next generation.

In addition to the black-footed ferret cloning project, scientists are also collecting and storing frozen tissue samples of all endangered species in the US. This can be considered a valuable resource in the future to fight extinction.