Scientists at Harvard University have identified the DNA switch that allows for whole-body regeneration. Animals such as salamanders and geckos can perform incredible feats of repair, growing back entire limbs over the span of a couple of months. Jellyfish and sea anemones can even regenerate their entire bodies after being cut in half. The Harvard researchers have discovered that a section of non-coding or “junk” DNA in worms controls the early growth response (EGR) genes. This “master control gene” acts like a switch that turns regeneration on or off.
“We were able to decrease the activity of this gene and we found that if you don't have EGR, nothing happens," Assistant Professor of Organismic and Evolutionary Biology at Harvard Dr. Mansi Srivastava said. “The animals just can't regenerate. All those downstream genes won't turn on, so the other switches don't work, and the whole house goes dark, basically.”
The study observing three-banded panther worms and their regenerative abilities has crucial applications to human biology. Humans also carry EGR, producing it in small quantities when cells are stressed. The findings push scientists to find a way to tweak the master gene in humans to improve our regenerative abilities. Harvard post-doctoral student Andrew Gehrke thinks the solution is in the non-coding DNA controlling the gene. Once believed to do nothing, junk DNA is now receiving more attention for its role in our biology.
“Only about two percent of the genome makes things like proteins," Gehrke said. “We wanted to know: What is the other 98 percent of the genome doing during whole-body regeneration?”