The northern white rhino is almost gone. Could stem cells be used to preserve - or even revive - the endangered species?
Scientists at the Scripps Research Institute in La Jolla, Calif., think such a procedure might work for the endangered rhino and other species, BBC News reports.
The northern white rhino is one of the most endangered animals on Earth, while the drill - a west African monkey - is threatened by habitat loss and hunting.
The scientists report in Nature Methods that their stem cells could be made to turn into different types of body cell.
If they could turn into eggs and sperm, "test-tube babies" could be created.
Such applications are a long way off, but research team chief Jeanne Loring said she had been encouraged by the results on the rhino cells, which they had not really expected to be successful.
The goal will be to use stem cells to create gametes, and thus, new embryos, not simply cloned versions of existing animals. And the breakthrough is new. Using human stem cells, the kind already used in research for human applications, scientists have been able to generate stem cells using the skin cells of endangered animals like the rhino and the drill.
Robert Lacy, a conservation scientist at the Chicago Zoological Society and chairman of the Conservation Breeding Specialist Group attached to the International Union for the Conservation of Nature (IUCN), said the technique might one day help to bring endangered species back from the brink, although lots more work remained to be done.
"The prospects for using these techniques for continuing the genetic lineages of the last few individuals of a species will be a last-ditch effort, after we have failed to protect the species in earlier, simpler, cheaper, and more effective ways," he said.
"Only when numbers get so low that the genetic contribution of every last animal (including those represented only in frozen cell lines) contributes measurably to the total species diversity - maybe around 10 individuals - would we want to do everything possible to ensure that those genes are transmitted to future generations.
"Tragically, northern white rhinos have undergone just such a decimation."
MIT Technology Review has more on the process that led to the current breakthrough.
In 1972, a group of forward-thinking conservationists in San Diego began freezing skin samples from endangered species. The hope was that science would eventually find a way to use the cells to help revive these fragile populations.
"To think of the foresight they had in the 1970s to start this program," says Loring, director of the Center for Regenerative Medicine at Scripps. At that point, "no genome had been published, and the concept of this ever happening was science fiction."
Huge obstacles remain, but the good news for animals and humans alike may be the simultaneous advances that stem cell research has yielded. Even if the research still aims primarily to develop therapies for human maladies, this leap shows the potential benefits that could redound to other species in need.