Sonic The Hedgehog might be a classic video game that defines a generation, but the gene of the same name dates further. In the past few decades, scientists have gathered data from fossils, DNA sequencing, and embryological development to assemble the lessons of Sonic Hedgehog into the story of building a human body.
Initially discovered in fruit flies, the Sonic Hedgehog gene is highly conserved and found in species as diverse as mammals, reptiles, and birds. The mammalian version of the gene codes for a morphogen, a type of signalling molecule that elicits different cellular responses depending on its concentration. It is essential during embryonic growth, particularly in the development of the nervous and skeletal systems. Once considered to be generally silent after birth, this developmental pathway has recently been shown to be reactivated in adulthood. Several studies have demonstrated that Sonic Hedgehog signalling is also required for the survival and proliferation of certain cells such as tissue progenitor and stem cells. Alongside its function as a developmental morphogen, the gene is also involved in the injury-dependent regeneration of muscles and organs, such as the prostate and bladder.
Besides its effects on growth and development, other functions of the gene are actively being dissected, particularly its role in age-associated diseases including atherosclerosis, neurodegenerative diseases and sarcopenia where there is progressive loss of muscle mass. A decline in Sonic Hedgehog-mediated cell signalling during ageing was found to affect the regenerative potential of local stem cells, reducing an individual’s resilience to injury. Conversely, enhancing the gene’s activity has been found to prevent age-associated decline in stem cell functions.
From evolutionary science to developmental biology, Sonic Hedgehog indeed merits additional exploration and investigation for its potential applications in molecular therapy for certain groups of target patients.
Ms Low Shin Yi
Duke-NUS’ Programme in Cancer and Stem Cell Biology
Assistant Professor Tang Hong-Wen
Duke-NUS’ Programme in Cancer and Stem Cell Biology