Rare lizard provides insight into limb regeneration

It's a well known fact that salamanders are able to re-grow limbs after amputation. However, the axolotl salamander from Mexico is able to quickly regenerate functioning jaws, skin, organs and parts of its brain and spinal chord -- in fact, at a much faster rate than its common cousins. Should the salamander becomes injured, it covers the wound with a stem-cell like growth, from which grows the replacement body part. "Humans do repair tissue but they don't repair it perfectly," says Elly Tanaka from the Centre for Regenerative Therapies in Germany. "The axolotl under certain injury conditions can go into kind of a mode where they repeat the process of the embryo."

Because of its unique regenerative abilities, the axolotl salamander is the focus of a years-long study by a team of scientists led by Dr. Tanaka. The goal of the researchers is to gain insights into future regenerative treatments for human medicine, for example, to repair spinal cord injuries. Their work is being supported the Department of Defense, which has stepped up to the plate with a $6.25 million grant in the hopes of finding better ways to help wounded veterans heal.

Their research involves experiments that allow them to watch the lizard's regenerative process up close. Toward this end, Dr. Tanaka has succeed at inserting the green-fluorescent protein GFP marker into the genome of the axolotl, thereby enabling her and her team to observe in detail the fate of individual cells and tissues. The scientists are also mapping the genome of the axolotl, which, surprisingly, is ten times larger than the human genome. Their goal is to map the regenerative abilities of the lizard, then insert the trait in humans -- a long-term objective to be sure, but one that Dr. Tanaka and her team feel confident they can achieve.

News Release: Human limb regeneration is no longer just a job for the Men in Black  www.blogs.amctv.com July 8, 2009