Humans and many other animals lack the ability to regenerate (replace by new growth) lost body parts, but salamanders can. When a salamander limb is amputated, the skin expands to cover the wound and cells in the vicinity loose their normal features and form a blastema, which will ultimately produce the missing structures. Such an amputation results in the regeneration of only the structures that were removed. However, if a discontinuity is created by grafting a distal-level blastema to a more proximal limb stump, the stump tissues are instructed to fill in the gaps or intercalate the missing limb elements. Normally intercalary regeneration does not occur when a mature limb structure, such as a wrist or hand is grafted to a proximal level stump. Drs. Eckberg and Crawford have determined that regeneration in the latter condition can be restored by introducing certain protein growth factors between the grafted hand or foot and the stump. This creates a unique opportunity to decipher the molecular cues that drive regeneration of the middle parts of the limb and regeneration in general. Ultimately, this work could lead to methods to bring about similar regeneration in humans. These studies are in a new area of interest for Dr. Eckberg and will involve both graduate and undergraduate students from Howard University a predominately minority institution together with undergraduates from St. Mary's College of Maryland.
