A United Kingdom research team's discovery of a new molecular cue that promotes limb regeneration in newts - a finding that could help guide the field of regenerative medicine - received the 2008 Newcomb Cleveland Prize of the American Association for the Advancement of Science (AAAS).

The Association's oldest prize, now supported by Affymetrix, the Newcomb Cleveland Prize annually recognizes the author or authors of an outstanding paper published in the Research Articles or Reports sections of the journal Science between June and the following May.

When an amphibian's limb is severed, a variety of cell types revert to their earlier stem cell form and then proliferate at the tip of the stump to form a mass of undifferentiated cells, the "blastema," from which the new limb grows. The formation of the blastema requires signaling molecules from nearby nerves, though this process has been poorly understood.

Five Science authors - Anoop Kumar, James W. Godwin, Phillip B. Gates, and Jeremy P. Brockes of University College London, along with A. Acely Garza-Garcia of the U.K.'s National Institute for Medical Research, were recognized for their article, entitled "Molecular Basis for the Nerve Dependence of Limb Regeneration in an Adult Vertebrate." (Reference: Science, 2 November 2007, Vol. 318, no. 5851, pp. 772-777. DOI: 10.1126/science.1147710.)

The researchers reported that the protein nAG helps to stimulate the proliferation of the blastema cells. The protein is secreted by both nervous-system cells called Schwann cells and epidermal cells near the wound, which helps explain why nerves are required for blastema formation. Even when the nerve was severed beneath the stump tip, the authors were able to coax the formation of a blastema by artificially inducing cells to express the protein. The blastema was capable of generating a new limb with normal shape, though the limb wasn't fully functional and lacked normal nerve supply.

The prize was established in 1923 with funds donated by Newcomb Cleveland of New York City and was originally called the AAAS Thousand Dollar Prize. It is now known as the AAAS Newcomb Cleveland Prize, and its value has been raised to $25,000. The winner also receives a bronze medal, as well as complimentary registration and reimbursement for reasonable travel and hotel expenses to attend the AAAS Annual Meeting. Eligible Science papers include original research data, theory, or synthesis. They should represent a fundamental contribution to basic knowledge, or a technical achievement of far-reaching consequence. Winning nominations also should be a first-time publication of the author's own work.