The regeneration game

摘要

When he has time to look out of the window, developmental biologist Sanjay Nigam likes looking at the graceful Torrey pine trees surrounding his office at the University of Calif ornia, San Diego. They remind him of kidneys. Kidneys? He explains: kidneys grow in a similar way to trees. "You start with a bud then it goes through various rounds of branching." The finished organ contains about one million "twigs", or tubules, which do the job of filtering toxins from blood. Nigam's team studies how kidneys develop in the embryo in the hope of learning how to persuade damaged adult kidneys to repair themselves. They believe that if they can pin down the chemical signals that initiate and orchestrate kidney development, they could trigger regrowth on demand simply by giving patients the compounds as drugs. And it's not just kidneys. Researchers elsewhere are also trying to discover how to persuade the body to regrow tissues such as heart muscle, or even whole organs such as hearts and lungs.