Researchers, from the University of Washington, have been studying the invertebrate that is, genetically, closest to humans. This is the acorn worm, which can be found in the sand around coral reefs.
The worms (which are hemichordates) can, somewhat miraculously, regrow their head, nervous system and internal organs after being sliced in half. The researcher hope that sufficient study will reveal the genetic network that allows this to happen and such knowledge could enable humans to regrow limbs.
With the worm, the regrown structure is in perfect proportion to the existing half, no matter where along the worm’s body the cut is made. The regrowth happens within a few days, depending upon the complexity. Here the regrowth of heart and kidneys takes 10 days; whereas a mouth can be grown in around three days.
The worm also survives after being cut into two, no matter where the incision is made. So perfect is the mechanism it is impossible to distinguish a regrown worm from one that has not undergone the regenerative transformation.
The research group have begun the slow and steady process of understanding gene expression and the precise mechanisms that can explain the regeneration process. The aim is to find the ‘master control’ gene that should reveal the mystery of the process.
In a research brief, one of the researchers involved in the study to date, Shawn Luttrell, explains why studying the worms is beneficial: “We share thousands of genes with these animals, and we have many, if not all, of the same genes they are using to regenerate their body structures.”
The research findings are published in the journal Developmental Dynamics. The research paper is titled “Head regeneration in hemichordates is not a strict recapitulation of development.”
