Sonic the Hedgehog platforming of the main levels. The 16-bit "Sonic the Hedgehog " consisted of a giant rotating maze, which many considered a major technical achievement. The most common special stages, however, were segments with the character running through a long tunnel to collect certain items. 3D "collect item" levels, as in "Sonic 3" and "Sonic & Knuckles", used the same perspective but had Sonic collecting all the blue-colored orbs on the surface of a giant sphere. Finally, "Sonic Advance 2" employed a 3D ring-collecting stage, and "Sonic Chaos" ("Sonic and Tails" in Japan) used a variety of gimmicks for its levels.
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,