Zoo plans to bring rare animals back from the dead

Take frozen cells from a dead animal, reprogram them to become sperm and eggs, then use these to bring endangered species back from the brink.

That's the aim of a collaboration between the San Diego zoo and The Scripps Research Institute in La Jolla, California. At the annual meeting of the International Society for Stem Cell Research in San Francisco last week, Inbar Friedrich Ben-Nun and Jeanne Loring of Scripps described how they have created induced pluripotent stem (iPS) cells from the frozen skin cells of a deceased male drill (Mandrillus leucophaeus), an endangered monkey found in Nigeria, Cameroon and Equatorial Guinea.

The team's long-term goal is to coax iPS cells into becoming sperm and eggs. They will be making iPS cells from tissue held by San Diego zoo's Frozen Zoo project - which has samples from some 8400 individuals representing more than 800 species. The sperm and eggs could be used in IVF treatments to add genetic diversity to captive breeding programmes. "You could actually breed from animals that are dead," says Loring.
To create the iPS cells, the team used viruses engineered to carry four human genes that can reprogram adult cells into an embryonic stem cell state. However, the trick failed to work with cells from the northern white rhinoceros. Loring says it may be necessary to use rhino versions of the genes.

Another problem is that the reprogramming genes can make the iPS cells cancerous, though other researchers have developed techniques to make iPS cells without leaving copies of the genes behind.
by Peter Aldhous
via New Scientist