ABOVE: A flatworm whose “degrowing” phase was suppressed towers over a control worm
NORTHWESTERN UNIVERSITY
Repressing a gene in planarian flatworms (Schmidtea mediterranea) that prevents stem cells from producing a key growth factor results in the animals doubling in size, report the authors of a study published on January 20 in Current Biology.
The flatworms are known for their extraordinary ability to regenerate themselves after almost every kind of injury, a process that involves a growing phase followed by a “degrowing” phase during which the worm is scaled back to restore its proportionality. It was the rescaling phase that the researchers blocked in the study.
“These worms have essentially discovered a natural form of regenerative medicine through their evolution,” says Christian Petersen, who studies regeneration at Northwestern University and is coauthor of the paper, in a university press release. “Planarians can regenerate their whole lives, but how do they limit their ...
