“This method paves the way to save endangered species such as the giant pandas, cheetahs, tigers, gorillas in East Africa, and even extinct species like the bucardo mountain goat,” says Robert Lanza, chief scientific officer at Advanced Cell Technology. “It will open the way for new strategies to help maintain biodiversity and to respond to the challenges of large-scale extinctions ahead.” Lanza was not involved in the study.
For animals like the white rhinoceros, each death represents a serious loss to the gene pool, which in turn weakens the population. By creating stem cells from animals that died, “their genes could be reintroduced to maintain the survival and genetic diversity of the species,” says Lanza. “The bucardo mountain goat could be resurrected using this technology if combined with an ordinary goat breeding program.”
Creating a new animal from a stem cell is likely a long way off. Researchers would need to first create sperm or eggs from the stem cells and then use them with sperm or eggs from a living animal to create an embryo. Fertility scientists are avidly searching for ways to develop sperm and eggs from stem cells in order to treat human infertility, and Loring hopes those technologies could be applied to these animals.
Prior to the development of iPS cell reprogramming, Lanza’s group used cloning—the method used to create Dolly the sheep—to try to reproduce two species of wild cattle; the guar and the critically endangered banteng. But cloning is ill-suited to species conservation, since it is a technically challenging process that often results in sick or deformed animals.
Lanza says another way to use stem cells to propogate endangered species would be to inject the cells of a more common, related species into the embryo, and then use various experimental techniques to coax the cells descended from the endangered animal to grow into a fetus. His team has shown this approach works in mice.