Scientists have some new insights into the workings of one of the few animals that can arguably live forever. Hydras are tiny organisms related to jellyfish. They have simple bodies, a cylindrical tube called a body column, with a head structure at the top and a sticky foot on the opposite end.
This process has long been a source of fascination for researchers eager to understand how it works down to the genetic level. A new study published Wednesday in Genome Biology and Evolution digs into how a Hydras genes are regulated in a field known as epigenetics to allow it to keep growing back and always be heading up.
A key finding is that the process for head regeneration is different than the one for reproducing, which happens through an asexual process called “budding.” Hydras reproduce by forming “buds” along the body column that eventually develop into new, independent animals with their heads.
Aide Macias-Muñoz, a biologist at the University of California, Irvine, and the paper’s lead author, said that even though the result is the same, gene expression is much more variable during regeneration. The study provides some new insights into the processes behind regeneration, which have been a mystery to scientists. It finds that Hydras use sequences of DNA called “enhancers” that regulate regeneration on the genetic level.