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 including the limb and midline structures in the brain, spinal cord, the thalamus by the "zona limitans intrathalamica" the lungs, and the teeth. Mutations in the human sonic hedgehog gene, "SHH", cause holoprosencephaly type 3 HPE3 as a result of the loss of the ventral midline. Sonic hedgehog is secreted at the zone of polarizing activity, which is located on the posterior side of a limb bud in an embryo. The sonic hedgehog transcription pathway has also been linked to the formation of specific kinds of cancerous tumors, including the embryonic cerebellar tumor, and medulloblastoma, as well as the progression