The birth of the first apparently healthy clone of an endangered species was announced today. Scientists at Advanced Cell Technology (ACT) of Worcester, Massachusetts, say they've got a peppy and "totally normal" banteng--a wild bovine from Java. It was born to a surrogate mother cow on 1 April.
This is not ACT's first attempt. Two years ago, company scientists had generated a clone of an endangered wild Asian ox, called a gaur. It died of dysentery 2 days after its birth in January 2001. In the most recent effort, scientists took frozen tissue held at the San Diego Zoo from a male banteng that died in 1980. They inserted skin cell nuclei into cow eggs. Blastocysts were then implanted in 30 cows. There were 16 pregnancies of which two came to term. The healthy banteng had an identical twin born to another cow on 3 April. But it (the animals are yet to be named) was twice the normal birth weight and was euthanized today, says Robert Lanza, ACT's vice president of medical and scientific development.
Lanza insists Banteng #1 gives every sign of being more than OK. "This animal is so healthy we gave him two entire pens." Within minutes of being born, he adds, "he let out this big bellow and everyone cheered." Plans are to introduce the clone into the zoo's small banteng population in a few weeks.
However, some scientists worry that Banteng #1 may ultimately meet an unhappy fate. "I strongly disagree that these clones are 'normal' just because they survive the postnatal period and appear normal," says Rudolf Jaenisch of the Massachusetts Institute of Technology. He points out that many cloned mice appear normal in youth but "die much earlier than controls with major problems in multiple organs." And cloned cows that appeared normal have also developed problems, such as seizures and tumors in late life, he adds.
That doesn't mean the clones can't help their wild brethren. Bantengs, whose world population reportedly has dwindled to about 8000, need a shot of genetic diversity. Fortunately, says Jaenisch, "it does not matter whether the clones themselves are normal or abnormal. As long as they can produce mature gametes, their offspring will be normal."