BAR HARBOR – In a seminal 2013 study, MDI Biological Laboratory scientist James Godwin, Ph.D., discovered that a type of white blood cell called a macrophage is essential to limb regeneration in the axolotl, a Mexican salamander that is nature’s champion of regeneration.

Without macrophages, which are part of the immune system, regeneration did not take place. Instead of regenerating a limb, the axolotl formed a scar at the site of the injury, which acted as a barrier to regeneration, just as it would in a mammal such as a mouse or human. Read more