Super Sonic; April 1994; Scientific American Magazine; by Rennie; 1 Page(s)

The shape of a hand is as comfortingly familiar as, well, the back of one's hand. But to developmental biologists, it is also an enigma. What biochemical sculptor molds the delicate embryonic tissues into limbs and functioning organs during the first weeks of life? Researchers think they have finally found a family of genes that nudge embryonic cells toward their proper destiny. One of these genes is a real overachiever : in vertebrate organisms, it organizes the central nervous system, defines the orientation of limbs and specifies where fingers and toes should grow. Its discoverers have whimsically--and appropriately--dubbed this gene Sonic hedgehog, after the hyperactive hero of a popular video game.

Cliff Tabin of Harvard Medical School, Andrew P. McMahon of Harvard University and Philip W. Ingham of the Imperial Cancer Research Fund in Oxford, England, lead the three laboratories that recently brought Sonic into the spotlight through a set of papers in Cell. Their demonstration that Sonic induces dramatic changes in embryos, Tabin explains, "opens the door. It's a great start for looking at signaling events early in embryogenesis."