Researchers from Harvard University just published a study in Science that reveals their discovery of numerous DNA switches that govern whole-body regeneration in three-banded panther worms. In addition to panther worms, whole-body regeneration is unique to animals like jellyfish, sea anemones, and planarian worms, while partial regeneration is observed in others, like salamanders and geckos. The new research sheds light on how these animals accomplish this unique feat.
As Phys.org reports, the team discovered that specific sections of the three-banded panther worms’ non-coding DNA exert control over the activation of a “master control gene.” This gene, called early growth response (EGR), acts as a power switch that turns various biological processes on and off, including regeneration.
“What we found is that this one master gene comes on…and that’s activating genes that are turning on during regeneration,” said Andrew Gehrke, a post-doctoral fellow at Harvard and lead author on the study. “Basically, what’s going on is the non-coding regions are telling the coding regions to turn on or off, so a good way to think of it is as though they are switches.”
But for this process to work, Gehrke said the tightly packed worm cell DNA must be opened up to allow new areas to accommodate the activation of the regeneration cells.
“So one of the big findings in this paper is that the genome is very dynamic and really changes during regeneration as different parts are opening and closing.”
Mansi Srivastava, Assistant Professor of Organismic and Evolutionary Biology at Harvard University, and senior author on the study, added that animals must have the EGR gene for regeneration to occur. The team discovered this by decreasing the activity of the EGR gene in the panther worms and observing that all the genes downstream from it were not turned on, according to The Telegraph. And when they’re not turned on, other switches and not flipped and no regeneration happens,
Here we present the labs first research paper, led by @Andrew_Gehrke, where we sequenced the genome of Hofstenia in order to understand how the non-coding portion of the genome responds to whole-body regeneration. Thank you to everyone involved!https://t.co/jOBC0BqsU2 pic.twitter.com/osM4ST4n4r
— Srivastava Lab (@acoel_hofstenia) March 14, 2019
From here, the team is aiming to examine whether the switches that EGR activates to cause regeneration are identical to those utilized during the development of the genome. In addition, they want to continue studying the biological processes that EGR and other genes use to create regeneration in three-banded panther worms and other species.
The findings highlight the importance of understanding the human genome and its non-coding portions. It also raises the question of whether humans can activate EGR when our cells are injured and, if so, why can’t these cells regenerate?