At http://www.sciencedaily.com/releases/2012/09/120926133115.htm

Biologist Discovers Mammal With Salamander-Like Regenerative Abilities

African spiny mouse specimen collected in the field near Nairobi Kenya. (Credit: Photo by Ashley Seifert)

ScienceDaily (Sep. 26, 2012) — A small African mammal with an unusual ability to regrow damaged tissues could inspire new research in regenerative medicine, a University of Florida study finds.

For years biologists have studied salamanders for their ability to regrow lost limbs. But amphibian biology is very different than human biology, so lessons learned in laboratories from salamanders are difficult to translate into medical therapies for humans. New research in the Sept. 27 issue of the journal Nature describes a mammal that can regrow new body tissues following an injury. The African spiny mouse could become a new model for research in regenerative medicine.

"The African spiny mouse appears to regenerate ear tissue in much the way that a salamander regrows a limb that has been lost to a predator," said Ashley W. Seifert, a postdoctoral researcher in UF's biology department. "Skin, hair follicles, cartilage -- it all comes back."

That's not the case in other mammals, he said. Usually scar tissue forms to fill the gap created by a wound.

The spiny mouse also regrows tissue on its main body when injured but not as completely as it does in its ears. "On their backs, they regrow hair follicles and skin, but the muscle beneath the skin doesn't regenerate," Seifert said.

Seifert was studying scar-free healing in amphibians when a colleague told him that a small rodent he had observed in Africa seemed capable of autotomy, a defense mechanism whereby the animal self-amputates a body part to escape a predator... (more at http://www.sciencedaily.com/releases/2012/09/120926133115.htm )