Altering the physiological circuits of flatworms makes them grow the heads of other species
A new research project at TuftsUniversity in Massachusetts has seen biologists successfully induceflatworms of a specific species to grow the head and brain you'dexpect to find on another species. Not only does the breakthrough addto our understanding of exactly what governs the growth of anatomy,but the knowledge gained may also have practical uses down the line,helping us better understand and even fix birth defects.
For the study, the researchers workedwith flatworms known as Girardia dorotocephala – a species withadvanced regenerative capabilities, including the ability to regrowmissing parts of their anatomy. Exploiting this trait, the scientistsattempted to alter the physical attributes of the creatures –specifically the morphology of their heads – by interruptingprotein channels between cells, which are used to pass informationback and forth via electrical signals.
The results were extremely pronounced,with not only the outer appearance of the creature's head changingafter the testing, but also the actual shape of the brain and thedistribution of the worms' stem cells. The researchers found that the closer the target species was tothe Girardia dorotocephala used for testing, the easier it was to induce the change.
So, what does all that actually mean?Well, the most important finding is that the characteristics ofanatomy are not hard-wired by the genome, but can be affected bybioelectrical networks between cells. The fact that the closer twospecies are on the evolutionary timeline directly effects the ease ofthe transformation also suggests that long-term changes inphysiological circuits play a key part in the wider evolutionaryprocess.
Interestingly, the physical changeswere found to be only temporary. Once the worms began regeneratingagain after some weeks, they reverted to their original, natural headmorphology. Further research will be required to find out exactly whythis is, but the study as a whole could have some big implicationsdown the line, providing insights that could help doctors fix birth defects or improve healing after an injury.
"This kind of information will becrucial for advances in regenerative medicine, as well as a betterunderstanding of evolutionary biology," says study lead author MayaEmmons-Bell.
The findingsof the study, including a computational model that explains exactlyhow the disruption of cell-to-cell communications leads to thealtered anatomy, were recently published in the International Journal of Molecular Sciences.
Source: Tufts University