Sonic The Hedgehog Has A Gene Named After Him, And That's Weirdly Appropriate
On the fifth day of Christmas, my true love gave to me
Five gold rings ...
The five gold rings in the "12 Days of Christmas" sound like the only decent gift in the whole song. But it turns out they're not actually talking about jewelry. The line really refers to ring-necked birds, like pheasants, so this is yet another reference to an increasing number of birds.
When we think of gold rings, we also don't think about jewelry, since we can't afford any. Our minds instead go to Sonic the Hedgehog grabbing rings out of the air. Sonic the Hedgehog—who did not sponsor this newsletter, don't worry—pops into lots of other people's heads too, which explains why scientists went and officially named a protein "Sonic hedgehog," while the gene that codes the protein is the sonic hedgehog gene, shh.
It's a variant of another gene simply called the hedgehog gene, hh, found in flies. The gene is all about how the body develops, and when it messes with flies, they get weird hairs, kind of like a hedgehog. Then scientists found more and more variations of the gene and had to come up with related but slightly distinct names. And so we got genes named desert hedgehog and Indian hedgehog, followed by sonic hedgehog and—even more ridiculous—tiggywinkle hedgehog.
In humans as well as flies, these genes control the Hedgehog signaling pathway, which is related to cell differentiation. When we're fetuses starting out, we just have one eye all fused together. Then sonic hedgehog kicks in and splits them apart into two eyes. And hey, you know who else has their eyes fused together? Sonic the Hedgehog, who has one big white shape in his face with two pupils, at least until they were split apart for the movies.
When the gene acts up, it causes all kinds of nasty problems, and doctors explaining those problems have to refer to "the sonic hedgehog gene" to baffled, increasingly angry patients. At least it's better than the "lunatic fringe" gene (which has nothing to do with mental illness). Or the "Mothers against decapentaplegic" gene (not named after an actual organization).
Top image: Sega