When you hear the words “Sonic Hedgehog,” an image of a furry blue animal capable of running at the speed of light is probably what first comes into mind. But did you know that Sonic Hedgehog (SHH) is also an important gene?
The hedgehog gene (hh) was first discovered in the fruit fly in 1980. The loss of function mutation causes the fruit fly embryos to be covered with pointy projections that look like the spikes of a hedgehog. Three homologs of hh were found, including desert hedgehog and Indian hedgehog—named for actual hedgehog species. But the third was named by a postdoctoral fellow when his wife came home with a magazine showing Sonic the Hedgehog in an ad! It gets even weirder when variations of hh occur; some have been known as echidna and tiggywinkle!
The SHH gene is found on chromosome 7 and provides instructions to make a Sonic Hedgehog protein. The protein plays a role in cell growth and specialization. It also helps develop the central nervous system, eyes, and limbs. Sonic Hedgehog, along with other signaling proteins, are required to form the hemispheres of the brain.
However funny the name may sound, the sonic hedgehog transcription pathway has led to a lot of serious diseases, such as medulloblastoma and holoprosencephaly. Patients with these diseases often think of the name as offensive or cruel. According to biology professor Dr. Chris Doe, “It’s a cute name when you have stupid flies… when it’s linked to development in humans, it’s not so cute anymore.”
Links for further reading:
‘Sonic Hedgehog’ Sounded Funny, at First
Human developmental disorders and the Sonic hedgehog pathway
Carroll CARES 