There may be more than one way to skin a cat, but before you go all Cruella de Vil on the local felines take a minute to consider an easier prospect: African Spiny Mice. These particular rodents have an intriguing adaptation. If one of these mice is attacked by a predator its skin breaks away easily, giving the mouse precious seconds before the predator realises it has only come away with an appetiser, while the main course is still running for cover. The process of dropping body parts to evade predation is known as autotomy and it is very rare in mammals relative to other classes. Most observed cases in mammals relate to caudal autotomy (detachment of the tail) in rodents, a feat that African Spiny Mice are also capable of. The example of a lizard “dropping” its tail is perhaps the best known example of autotomy in nature, but many other species display autotomy as a defensive behaviour.
While skin autotomy is in itself a fascinating phenomenon, what’s even more remarkable is that the mice can quickly close the wound and regenerate the lost skin complete with sebaceous glands and follicles. This amazing restorative capacity even extends to damaged ear tissue.
So why should we be getting excited about this? After all we’ve observed more extreme feats of regeneration elsewhere in the animal kingdom. Surely a mouse growing its skin back is less impressive than a salamander regrowing a fully functional limb following amputation? Ashley Seifert of the University of Florida explains the significance “… these animals could become a new model for understanding mechanisms that regulate regeneration in mammals. Like rabbits, their ability to regenerate new hair follicles and ear tissue, including cartilage, means they have “unlocked”, for lack of a better term, their regenerative ability. In general, mammals are poor regenerators. There are plenty of hypotheses about why this is, but it’s been difficult to test. These animals provide a tool to do that.”
It is because they are mammals, like us, that these mice are of such special interest. Due to our mammalian commonalities, they may prove to be useful model organisms in the field of Regenerative Medicine. The possibilities are enticing, but there is still much to learn from these fascinating creatures. Whatever secrets these mice keep, Seifert seems determined to unveil them , “At the end of the day, I wonder about things, and as a scientist, there is nothing better than being able to act on that wonder to find out why something happens the way it does. Of course, this always creates more questions, but that’s part of science. Its our choice to determine just how far down the rabbit hole we want to go. I for one plan to follow these guys as far as they will take me.”
As for the method of regeneration? It appears that it follows a similar course to that observed in some amphibians. Following limb loss, salamanders first heal the wound via epithelial cells migrating to cover the exposed tissue. Shortly afterwards a blastema (a mass of progenitor cells) is formed at the distal portion of the wound stump. These cells then differentiate forming the necessary tissues to reconstruct the lost limb. This process is very similar to the way limbs develop during embryogenesis.
So there you have it. If you’re still hell bent on making a fur coat, put down the cat and lose the razor. Just grab yourself a few spiny mice and start pinching. Personally I don’t find the idea of a mouse-fur coat to be particularly appealing, but if you want to flaunt your verminous ensemble all over town like some kind of demented Disney villain then go nuts. It’s no skin off my back.
Eastern Spiny Mouse Marcel Burkhard alias cele4
Tissue Regeneration: Seifert et al. 2012 supplementary material.
Many thanks to Ashley Seifert for his contribution to this post.