Mice Cloned After 16 Year Freeze

Cells taken from mice frozen 16 years ago have grown into healthy clones, raising the possibility of reproducing long-dead animals and even resurrecting extinct species.

The accomplishmen represents a large step forward in animal cloning. Earlier clones have required tissues taken from living animals or carefully-preserved cells, rather than an entire frozen animal.

Scientists thought that freezing would damage cells beyond repair. But the scientists salvaged intact nuclei from the neurons of their mice. These were inserted into living mice eggs, forming an embryo that developed until embryonic stem cells could be harvested. The stem cells were then used to make healthy mouse pups.

According to scientists, the new technique might someday be used to clone "extinct animals frozen in permafrost, or specimens collected opportunistically from endangered species in the field without access to sophisticated laboratory facilities."

Original article here.