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 but low in the developing bronchi. Mice who are deficient in SHH can develop tracheoesophageal fistula (abnormal connection of the esophagus and trachea). Additionally, it a double (SHH-/- ) knockout mouse model exhibited poor lung development. The lungs of the SHH double knockout failed to undergo lobation and branching (the abnormal lungs only developed one branch compared to an extensively branched phenotype of the wildtype). Sonic hedgehog may play a role in mammalian hair cell regeneration. By modulating retinoblastoma protein activity in rat cochlea, sonic hedgehog allows mature hair cells that normally cannot return to a proliferative state to divide