for National Geographic Today
For the first time scientists have successfully created a viable clone
of an endangered species—the European mouflon, one of the smallest
wild sheep in the world.
The effort, led by Pasqualino Loi, of
the University of Teramo, Italy, trumped the work early last year of
U.S. company Advanced Cell Technology whose clone of an endangered Asian
ox died of dysentery 48 hours after birth. The apparently healthy lamb
is now about seven months old and currently living in a wildlife center
in Sardinia. The work is reported in the October issue of Nature
Biotechnology.
The European mouflon is an endangered species of sheep in its original habitat: the Mediterranean islands of Sardinia, Corsica, and Cyprus. The animal nearly died out in Europe a hundred years ago and almost disappeared from the islands that were their first home (see sidebar).
Ever since the creation of Dolly, a sheep that was the first animal to be cloned, conservationists have debated the controversial merits of cloning as a means of rescuing populations of endangered and threatened species.
Those in support of the idea, like Loi and his colleagues, suggest collecting cell samples from a variety of endangered species while their numbers are somewhat high—thus ensuring that a range of genetic diversity is essentially bottled. Should the population disappear the original pool of genes can be regenerated through cloning.
Others feel that cloning gives a false sense of security that populations of endangered animals can easily be rekindled. For these groups conservation through habitat preservation is the better way to protect these species.
Betsy Dresser, director of the Audubon Center for Research of Endangered Species, in New Orleans, disagrees. "Saving habitat may not be enough," she said.
"Any tool for saving endangered species is important," said Dresser. "Cloning is just another reproductive tool, like in-vitro fertilization."
Probably the most valuable aspect of cloning is to reintroduce specific members of a species that represent a "significant slice of the gene pool pie," said geneticist Oliver Ryder, of the Center for Reproduction of Endangered Species at the San Diego Zoo in California. A key member of a species may, for example, have died in captivity before it could produce offspring.
If cloning is managed properly, said Dresser, it can even expand the genetic pool. "It may allow us to bring back genetic material from infertile animals, dead animals and even very young animals that were too immature to breed."
The mouflon lamb was cloned using "somatic cell nuclear transfer"—the same technique used in 1997 to clone Dolly. The only difference is that this time two species of sheep were used—the mouflon that was cloned and the domestic surrogate mother that carried the clone.
Cloning the mouflon lamb may be a small step scientifically, said Dresser, but it is important because it proves the value of using a common species as a surrogate mother for an endangered species.
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