Sonic the Hedgehog different media including animation, comic books, and a Hollywood film. The first "Sonic" game, "Sonic the Hedgehog", is a platform game released in 1991. Players control the anthropomorphic blue hedgehog Sonic, who can run and jump at high speeds using springs, ramps, and loops. Sonic must stop Dr. Robotnik from taking over the world using the Chaos Emeralds. "Sonic the Hedgehog 2" (1992) increased the overall size and speed of the series' gameplay and was the second best-selling Genesis game. It introduced Sonic's sidekick and best friend, Miles "Tails" Prower, who followed Sonic throughout the game, and allowed a second
Sonic hedgehog postdoctoral fellow at the Tabin Lab, after he saw a Sonic comic his daughter had brought from England. In the zebrafish, two of the three vertebrate "hh" genes are duplicated: "SHH a", "SHH b" (formerly described as "tiggywinkle hedgehog", named for Mrs. Tiggy-Winkle, a character from Beatrix Potter's books for children), "ihha" and "ihhb" (formerly described as "echidna hedgehog", named for the spiny anteater and not for the echidna character Knuckles in the "Sonic" franchise). Of the "hh" homologues, "SHH" has been found to have the most critical roles in development, acting as a morphogen involved in patterning many systems,