Sonic the Hedgehog Sonic the Hedgehog Sonic the Hedgehog is a video game franchise produced by Sega centering on a series of high-speed platform games. Sonic, the protagonist, is an anthropomorphic blue hedgehog with supersonic speed. Typically, Sonic must stop antagonist Doctor Eggman's plans for world domination, often helped by his friends, such as Tails, Amy, and Knuckles. The first "Sonic the Hedgehog" game, released in 1991, was conceived by Sega's Sonic Team division after Sega requested a mascot character to compete with Nintendo's mascot Mario. Its success spawned many sequels and helped Sega become one of the leading video game companies during
Sonic hedgehog of prostate cancer tumours. For SHH to be expressed in the developing embryo limbs, a morphogen called fibroblast growth factors must be secreted from the apical ectodermal ridge. Sonic hedgehog has also been shown to act as an axonal guidance cue. It has been demonstrated that SHH attracts commissural axons at the ventral midline of the developing spinal cord. Specifically, SHH attracts retinal ganglion cell (RGC) axons at low concentrations and repels them at higher concentrations. The absence (non-expression) of SHH has been shown to control the growth of nascent hind limbs in cetaceans (whales and dolphins). The sonic hedgehog