How humble worms could help humans to grow new brains

SCIENTISTS have discovered the gene that allows a worm to regenerate its own body parts after they are amputated.

The research into how Planarian worms can regrow body parts – including a whole head and brain – could one day make it possible to regenerate old or damaged human organs and tissues, the University of Nottingham said.

The research, led by Dr Aziz Aboobaker, a Research Councils UK fellow at the university's School of Biology, shows that a gene called "Smed-prep" is essential for correctly regenerating a head and brain in Planarian worms.

The worms' bodies contain adult stem cells that are constantly dividing and can become all of the missing cell types in the event of an amputation.

They also have the right set of genes working to make this happen as it should, so that when they regrow body parts they end up in the right place and have the correct size, shape and orientation, the research showed.

Dr Aboobaker said: "These amazing worms offer us the opportunity to observe tissue regeneration in a very simple animal that can regenerate itself to a remarkable extent and does so as a matter of course.

"We want to be able to understand how adult stem cells can work collectively in any animal to form and replace damaged or missing organs and tissues.

"Any fundamental advances in understanding from other animals can become relevant to humans surprisingly quickly."

He said the knowledge could help scientists formulate how to replace damaged and diseased organs, tissues and cells in humans.

"This would be desirable for treating Alzheimer's disease, for example," Dr Aboobaker said.

"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."

The researchers said Smed-prep is necessary for the correct differentiation and location of cells that make up a Planarian worm's head, as well as for defining where the head should be located.

They found that although the presence of Smed-prep is vital so the head and brain are in the right place, the worm stem cells could still be persuaded to form brain cells as a result of the action of other, unrelated genes.

But without Smed-prep these cells do not organise themselves to form a normal brain, the researchers said.

Daniel Felix, a graduate student who carried out the experimental work, said it had been a very exciting project.

He said: "The understanding of the molecular basis for tissue remodelling and regeneration is of vital importance for regenerative medicine.

"Planarians are famous for their immense power of regeneration, being able to regenerate a new head after decapitation.

"With the gene Smed-prep, we have characterised the first gene necessary."

The study is published in the journal PLoS Genetics.