Exotic pet boosts hope for medical miracles

The African spiny mouse, a desert rodent that has become an exotic pet, can shed up to 60 percent of the skin on its back and fully regrow the lost tissue, scientists reported on Wednesday. Understanding the trick could one day help burns victims in need of scar-free skin regeneration, they hope. The spiny mouse (Acomys) is well-known for eluding hunters by shedding its tail skin, rather as lizards jettison their tail. Exploring this phenomenon, biologists led by Ashley Seifert at the University of Florida in Gainesville found that the skin-shedding is even greater than expected. When they picked up two wild-caught specimens, Acomys kempi and Acomys percivali, the mice lost up to 60 percent of the skin on their backs when they were grabbed by hand in a normal manner. Closer inspection showed the skin to be remarkably fragile, requiring 77 less energy to tear than skin from its cousin the house mouse, Seifert's team reported in the journal Nature. But how the animal is able to shed such a big area of skin so easily remains a mystery. The researchers were unable to find any breakage point. The molecular or biomechanical properties are unclear. Even more impressive are the mouse's healing properties. Within 30 days of the skin shedding, a double dermal layer had regrown, with new follicles and no sign of so-called wound-bed tissue, a precursor of scarring. The regenerative capacity extended to the mouse's ears, where a small punched hole became completely recovered with healthy tissue, including sebaceous glands and cartilage. "Mammals may retain a higher capacity for regeneration than was previously believed," said the study. "Acomys may prove useful in identifying mechanisms to promote regeneration in lieu of fibrosis and scarring."