We do play God when we wreak havoc on the environment

Dr Robert Lanza

US scientists say that if the pregnancy proceeds normally, it will result in the first threatened animal to be born using cloning technology.

The Asian gaur should be delivered by its surrogate mother in November.

Some researchers believe cloning may offer the only way to save species from extinction. But conservationists argue there is little point if the reasons for the animals' decline, such as habitat loss, have not been addressed first.

Giant panda

Researchers at Advanced Cell Technology (ACT) in Massachusetts fused the genetic material from a dead male gaur with the empty egg cell of a cow to make their clone, which they have already called Noah.

Gaur numbers have dwindled to about 36,000

A total of 692 eggs were used in the experiment. Thirty-two embryo clones were initially implanted in surrogate mothers, but only eight of the adult cows became pregnant.

Of those, five miscarried, and two other foetuses were aborted for scientific purposes. A cow called Bessie now carries the one remaining gaur foetus.

"Noah will be just the first creature up the ramp of the ark of endangered species that we and other scientists are currently attempting to clone," researchers Robert Lanza, Betsy Dresser and Philip Damiani wrote in an article about their work that appears in the magazine Scientific American.

"Plans are under way to clone the African bongo antelope, the Sumatran tiger and that favourite of zoo lovers, the reluctant-to-reproduce giant panda," they added.

Both sexes

ACT also intends to revive an extinct species of Spanish mountain goat called bucardo.

The last known bucardo was killed nine months ago by a falling tree. But some of the animal's cells were preserved and these will now be used to bring the goat "back to life" next year.

Fusion: A nucleus is fused with an empty egg cell