Sonic the Hedgehog is Not Just for Video Games

Mar 07, 2019

By Julia DiFiore

Much like Fortnite today, Sonic the Hedgehog was everywhere in the early 1990s – from video games to comics and TV shows. What his creators probably didn’t expect was that Sonic would one day be part of a major scientific discovery – the inspiration for the name of a newly discovered gene.

Decades before the gene sonic hedgehog was discovered, two scientists laid the groundwork for its unique name. In the 1970s, Dr. Nüsslein-Volhard and Dr. Wieshaus were interested in a basic biological question: how do animals grow from one cell to a full-grown organism? At the time, scientists knew genes directed this process, but they wanted to know exactly which genes and what they did.

To answer this question, Nüsslein-Volhard and Wieshaus used fruit flies, which are widely used in research because they grow quickly, can produce many offspring, and are easy to care for. In their experiments, Nüsselein-Volhard and Wieshaus saw that when one particular gene was mutated, the fruit fly larvae (the part of the life cycle between a fertilized egg and a full-grown fly) looked round and spikey, like a hedgehog. So naturally, they named that gene hedgehog.

Along with creating some unique gene names, Nüsslein-Volhard and Wischaus’s work played a major role in answering that fundamental question of how one cell becomes an entire organism. In addition to hedgehog, they identified other critical genes that direct early developmental processes.  While they did their work in fruit flies, other scientists reasoned that evolution would have conserved those genes and their functions in other organisms.

Left: Diagram of the hedgehog mutant embryos where the denticles, or spikes, are prominent and closely grouped.
Right: An actual hedgehog.

In the 1990s, a group of researchers at Harvard successfully identified a group of genes similar to hedgehog in chickens, one of which they named sonic hedgehog after one of the researchers had seen his daughter reading a Sonic the Hedgehog comic book. A few years later, scientists discovered that humans also have a sonic hedgehog gene and that it plays an important role in brain development. Without sonic hedgehog doing its job, the two sides of the brain don’t properly separate and in the most severe cases, can be lethal.

Since that initial discovery in humans, sonic hedgehog has become an intensely studied gene because of its role in brain, limb, and lung development. Even some types of cancer, such as medulloblastoma, prostate, and ovarian cancers are linked to abnormal activity of sonic hedgehog. So while Sonic the Hedgehog may not be as prevalent in popular culture today as he was in the nineties, his namesake gene is still stirring up interest among scientists and physicians.

Edited by Rowan Beck