Well, this idea may be a long shot. Imagine turning on the ability to regenerate at your own will and turning it off when it is not needed: such trick would be perfect if performed at least with our teeth which we all lose in old age. But, well, it’s probably too simple. How about regenerating your entire… head?

Surprisingly, it is not a complete science fiction. Perhaps it will not work in us, humans, but there are other species which are perfectly suitable to become first ones to grow a new head instead of old one. And, the experiments of this particular kind are being done by scientists from Max Planck Institute of Molecular Cell Biology and Genetics and DFG-Center for Regenerative Therapies Dresden (CRTD) from Technical University of Dresden, Germany.

The idea explored by the teams of German researchers is to take species which does not have regenerative abilities, and to turn these abilities on. The only prerequisite is that this species would have ‘relatives’, in which regeneration works naturally and perfectly well.

In the paper describing their work, researchers formulate the problem in a very simple way: why there are species which are able to regenerate, while there are also some very similar species, which are not capable of doing this – this fact at least to some degree contradicts the concept of Natural selection formulated by Darwin. According to this theory and even considering a simple logic, the regenerative function is a significant advantage compared to its absence.

Motivated by this idea, researchers started studying planarian flatworms, which are known to science for their to regenerate different parts of their body. However, even planarian flatworms have related species with significantly weaker regeneration abilities.

Scientists from Max Planck Institute and Technical University of Dresden experimented with planarian species Dendrocoelum lacteum. This is a type of planaria flatworm which is not capable of regeneration due to particular genetic ‘defect’. Researchers determined that this regeneration-related defect is associated with inhibition of canonical Wnt signalling in other planarian species. Probably the most interesting finding is that regenerative ability was successfully turned on by manipulating the same Wnt pathway.

This finding has the potential of becoming a basis for exploring regeneration abilities in other kinds of organisms, especially more complex compared to planaria. Scientists hope to perform more comparative studies to determine exact genetic mechanisms controlling the regeneration function in different organisms and also to explain the evolutionary puzzle why some animals can regenerate and others not.