Compared with most vertebrate species, adult mammals are considered to have very limited regenerative capacity. Now, a report by Seifert et al. on two species of African spiny mice (Acomys) suggests that regeneration of certain tissues does occur in some mammals. Acomys skin tears with handling and, in the wild, can be shed in large amounts to escape predators. The authors found that Acomys species have skin that is 20-times weaker than the Mus species conventionally used in the lab. Acomys showed rapid healing of skin wounds and little evidence of scarring, whereas Mus deposited large amounts of extracellular matrix that contributed to fibrosis. In addition, unlike Mus, Acomys species contained regenerating hair follicles in newly healed wounds. Acomys species also showed rapid closing of 4-mm punch wounds in ear tissue, which involved regeneration of skin, hair follicles, sebaceous glands, adipose cells and cartilage (but not muscle). In contrast, Mus were incapable of closing ear punch wounds and formed a scar composed of cartilage. Finally, the authors show that tissue regeneration in Acomys might occur through formation of a structure resembling a blastema, a mass of lineage-restricted progenitor cells that has been characterised in amphibians that can re-grow limbs. These results highlight the value of studying diverse model organisms and open up new opportunities for studying regeneration in mammals.
Seifert A. W., Kiama S. G., Seifert M. G., Goheen J. R., Palmer T. M., Maden M. (2012). Skin shedding and tissue regeneration in African spiny mice (Acomys). Nature 489, 561– 565.
