Chinese goat clone dies

The US goat clones were healthy

The first goat to be cloned from an adult cell has died just 36 hours after being born, according to the Chinese state media.

The goat, named Yuanyuan, died early on Sunday because of abnormal lung development.

Its death highlights the continuing difficulty scientists have in producing healthy clones.

It is a setback for Chinese scientists who hope to use cloning to save the endangered giant panda from extinction. A panda embryo was successfully cloned in China in June 1999, but little news of the project has been reported since.

Sheep and goats

"The death means that cloning technology leaves much room for improvement," said Zhang Yong, a professor at Northwest University, Xian, China.

But despite the setback, the researchers say they will push ahead with new experiments and expect another cloned goat to be born later this month, followed by a cloned ox before the end of the year.

The Chinese media reports that scientists removed a cell from the ear of an adult goat and extracted its nucleus. They then used the nucleus to replace the nucleus of an egg cell which was subsequently injected into the womb of the surrogate mother goat.

This method is similar to that used to produce Dolly the sheep, the first mammal cloned from an adult cell.

Young and old

Earlier research, carried out at the Institute National de la Recherche Agronomique, France, suggested that the use of adult cells rather than embryonic cells can cause problems.

In that case, a cloned cow died at six weeks due to abnormal development of lymphoid tissues.

The Chinese animal was not the first goat to be cloned.

In April 1999, US scientists announced the birth of three healthy goat clones. They were born in late 1998 but were cloned using embryonic cells, not adult cells.

The clones were engineered to express a human protein which prevents blood from clotting.