Though it remains a topic of controversy among conservation biologists, the idea of using cloning technology to preserve endangered species has received serious consideration ever since the cloning of Dolly the sheep in 1997. But recent attempts to clone endangered mammals such as the argali and the gaur have failed to yield viable offspring. Now a European research team has met with success. According to a report in the October issue of the journal Nature Biotechnology, the same technique used to replicate Dolly¿somatic cell nuclear transfer¿has produced an apparently healthy mouflon lamb, a member of an endangered species of sheep found on Sardinia, Corsica and Cyprus.

Pasqualino Loi of the University of Teramo in Italy and his colleagues recovered so-called somatic granulosa cells from the ovaries of two female mouflons found dead in a Sardinian pasture and injected their nuclei into domestic sheep egg cells that had had their nuclei removed. The resulting embryos were then surgically implanted in four domestic ewes, one of which delivered a cloned baby mouflon after 155 days. At 25 days old, the time at which the researchers submitted their report, the little mouflon appeared normal.

"Although the nuclear donor cells were recovered from dead animals and considered nonviable, they were able to generate normal embryos and offspring," the team writes. "Our findings support the use of cloning for the expansion of critically endangered populations, both within a concerted conservation program and in extreme situations involving sudden death.