A team of biologists from Tufts University, Massachusetts (USA) has made flatworms develop heads and brains characteristic of other species without altering the genomic sequence . The work has been published in The International Journal of Molecular Sciences .
Scientists thus reveal a new type of epigenetics ( those processes that modify the activity of DNA without modifying its sequence, that is, genetic factors determined by the cellular environment rather than by heredity) that determines anatomy on a large scale . Thus, by manipulating electrical synapses, the scientists succeeded in making a group of flatworms ( Girardia dorotocephala ), associated with a great regenerative capacity, grow heads and brains associated with other species of worms.
The resulting changes included not only the general shape of the head, but also that of the brain as well as the distribution of the worm’s adult stem cells . Furthermore, the more closely related the two species were, the easier it was to effect such a change, reinforcing the connection to evolutionary history.
“ The sequence and structure of chromatin, the material that makes up chromosomes, is commonly thought to determine the shape of an organism, but these results show that the function of physiological networks can override the default species-specific anatomy. Thanks to the modulation of cell connectivity through electrical synapses , we have been able to derive head morphology and brain patterns that belong to a totally different species from an animal with a normal genome ”, explains Michael Levin, study leader.
These new findings, which were presented under a computer model that explained how changes in cell-to-cell communication gave rise to different types of shapes, will serve to correct birth defects or even the possibility of encouraging the growth of new structures biological after injury .
