The Hedgehog signaling pathway transmits the signals that direct correct cell differentiation during embryonic development and contributes to tissue regeneration in adults. Dysregulation of this pathway has been linked to certain cancers and is associated with a mutation in the Hedgehog (Hh) gene.

In 1980, the future Nobel laureates Christiane Nüsslein-Volhard and Eric Wieschaus published their study of how different mutations affect the embryonic development of the fruit fly Drosophila melanogaster. Gene loci whose mutations changed the way the larvae looked were named after the larvae themselves. Earlier researchers had already coined fused, wingless, and cubitus interruptus; Christiane and Eric described the variants gooseberry, hedgehog, and patched.

Hedgehog — because larvae with a mutation in that locus (named Hh) were short, almost stubby, and densely covered with denticles that looked like a hedgehog’s spines.

To see how the pathway works, watch the three-part series from the Onkoview YouTube channel, which uses visuals to explain the Hedgehog signaling pathway with and without the mutation:

• Part 1 (normal functioning)
• Part 2 (dysregulation)
• Part 3 (treatments)

The videos help to understand how the Hedgehog signaling pathway operates in both normal physiology and certain diseases, and they visualize the molecular processes clearly. It is a useful background for oncology or human biochemistry translation or writing projects.

Key terms to include in your glossary for oncology or human biochemistry projects:

• Hedgehog pathway
• Hedgehog ligand protein
• Patched (PTCH) receptor
• Smoothened (SMO)
• primary cilium
• axoneme
• basal body, base
• microtubule motor KIF7
• protein kinase A
• glycogen synthase kinase 3-beta
• casein kinase 1
• beta-TrCP subunit of the SCF-type E3 ligase
• ubiquitinated
• proteasome
• transcriptional repressor
• transcriptional suppressor
• transcriptional activator
• GLI-mediated activation
• G-protein coupled receptor
• proto-oncogenes

All terms are referenced in the first video.

The article (pdf) that opens with the “Open resource” button is the 1980 paper by Christiane Nüsslein-Volhard and Eric Wieschaus — the Drosophila genetic screen in which the Hedgehog gene was first described. There’s a photo of the larvae that gave the name to the protein and signaling pathway.