Source: Salk Institute for Biological Studies
Date: November 2, 2009
Summary:
Unlike humans, zebrafish are able to regenerate amputated appendages. The search for the holy grail of regenerative medicine -- the ability to "grow back" a perfect body part when one is lost to injury or disease -- has been under way for years, yet the steps involved in this seemingly magic process are still poorly understood.
Now researchers at the Salk Institute for Biological Studies have identified an essential cellular pathway in zebrafish that paves the way for limb regeneration by unlocking gene expression patterns last seen during embryonic development. They found that a process known as histone demethylation switches cells at the amputation site from an inactive to an active state, which turns on the genes required to build a copy of the lost limb.
Their findings, which will be published in a forthcoming issue of Proceedings of the National Academy of Sciences, U.S.A., help to explain how epimorphic regeneration—the regrowing of morphologically and functionally perfect copies of amputated limbs—is controlled, an important step toward understanding why certain animals can do it and we cannot.
