Gene that allows growing a new head identified

British boffins say they have identified the key "smed-prop" gene which allows Planarian flatworms to regenerate any part of their body following an injury - even their brains. The discovery is seen as a step towards regeneration therapy for humans in future.

Top bio-boffin Dr Aziz Aboobaker and grad student Daniel Felix, who carried out the new research, say that the discovery of "smed-prep" unlocks the mechanisms by which the hard-to-kill Planarians grow new muscle, gut and brain cells from stem-cells which are present even in adults. Even more importantly, it seems that the information contained in smed-prep also makes the new cells appear in the right place and organise themselves into working structures - as opposed to nonfunctional blobs of protoplasm.

Understanding the process completely in worms, according to Aboobaker, is a necessary prerequisite for making it happen in humans. Another cunning worm trick he wants to get to the bottom of is the method by which the Planarians cope with rogue stem-cells producing defective cells - regeneration gone wrong, after all, in basically cancer.

The doc suggests that it may be possible in future to simply grow new organs and limbs for injuried or sick humans - even, perhaps, to repair their damaged brain in situ. This would be preferable to removing a duff brain and growing a new one, as happens when a planarian worm's head is cut off.

"If we know what is happening when tissues are regenerated under normal circumstances, we can begin to formulate how to replace damaged and diseased organs, tissues and cells in an organised and safe way following an injury caused by trauma or disease. This would be desirable for treating Alzheimer's disease, for example," says Aboobaker.

"With this knowledge we can also assess the consequences of what happens when stem cells go wrong during the normal processes of renewal — for example in the blood cell system where rogue stem cells can result in Leukaemia," he adds.

Felix, who actually did the worm-chopping during the experimental programme, said:

"It has been a really exciting project and I feel very lucky".

Felix and Aboobaker's paper, The TALE Class Homeobox Gene Smed-prep Defines the Anterior Compartment for Head Regeneration, is available here free, courtesy of the journal PLoS Genetics. ®