A laboratory breakthrough by Italian scientists is poised to fuel a bitter ethical row about the use of embryos in transplant research, the journal Nature Neuroscience reports in October's issue.
The controversy has been sparked by stem cells -- primitive cells that scientists hope can be grown in a lab dish and then implanted to repair damaged organs, such as injured spinal cords or brains affected by Alzheimer's disease.
The most scientifically exciting stem cells come from embryos that are a few days old.
These cells have the extraordinary ability to develop in the womb into any part of the body, opening up dreams that they may be cloned and grown in a laboratory to become a universal source of transplant tissue.
But using embryo stem cells is hotly contested.
France, like many other countries, outlaws any scientific use of embryos for moral reasons, while Britain and the United States have issued cautious guidelines that would allow stem cells to be used in specific areas of research.
Opponents to embryonic research say the solution lies in adult stem cells, a new and largely overlooked area of exploration.
Their position now appears to have been strengthened by a team led by researchers from Italy's National Neurological Institute and Stem Cell Research Institute, based in Milan.
The scientists took stem cells from an adult brain and used them to grow skeletal muscle, both in culture and in animals.
The signal to reprogramming these stem cells appears to come from membrane contact with other cells rather than a secretion, they believe.
When the neural stem cells were in contact with other neural stem cells, they grew neurons and glia -- vital cells that act rather like electricity insulation in the nervous system.
And when the neural stem cells were in contact with muscle tissue, they grew muscle.
In a commentary, neuroscientist Charles Jennings said that the work was encouraging, but it was too early to abandon research using embryonic stem cells until the limits of adult stem cells were known.
But he warned the finding "seems likely to attract considerable attention, and along with several other recent reports, to provide new fuel for an increasingly strident debate on the ethics of human stem cell research."
Until recently, adult stem cells were known to exist only in certain types of adult tissue and it was considered impossible to reprogram them.
The obscurity of adult stem cells was compounded by the fact that they were only believed to exist in minute quantities and were also hard to isolate and purify -- PARIS(AFP)
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