Research in the United States has identified a gene that acts as a “fountain of youth” for adult stem cells, giving them the ability to renew themselves and supply the body with fresh tissue.

At present, stem cells from human embryos are generally considered to be the most promising targets for such research but their use is controversial because the embryo is destroyed when the cells are harvested. A method of growing specialised cells from adult tissue could provide alternative source material for some therapies, without raising the same ethical concerns.

Adult stem cells are master cells that resupply the body with specialised tissue such as neurons and red blood cells. Although normal cells will divide only a limited number of times, stem cells “refresh” themselves every time they split, producing a mature nerve or blood cell and a new stem cell.

The newly-discovered gene, known as Bmi-1, seems to be the key that allows adult stem cells to act in this way, replicating themselves as well as producing new tissue.

In a study at the University of Michigan, a research team led by Sean Morrison found that the gene is needed for two forms of nerve stem cell — from the central and peripheral nervous systems — to rejuvenate themselves when they divide.

Details of the work are published in Nature, with a separate study from Massachusetts General Hospital in Boston showing that Bmi-1 is also important in blood stem cells.

Dr Morrison said: “So far, we and our colleagues have studied three important types of adult stem cells, and Bmi-1 appears to work similarly in every case. This raises the intriguing possibility that Bmi-1 could be the universal regulator controlling selfrenewal in all adult stem cells.”

The findings might eventually help scientists to grow large colonies of adult stem cells, for use in medical therapies. It could also assist efforts to guide the development of the cells into the particular forms of tissue that are required for these treatments. The discovery is also significant for cancer research because cancer cells are the only types of cell that divide in the same way as adult stem cells.

In a separate study, scientists at the University of Leeds have derived hundreds of cells from a single cell removed from a mouse early embryo. If this technique can be repeated in human beings, it could greatly enhance the accuracy of a genetic screening procedure known as pre-implantation genetic diagnosis (PGD) that checks embryos for genetic defects before they are transferred to the womb in IVF. At present, PGD is performed using just one cell, and has an error rate of up to 3 per cent. Growing extra cells would allow scientists to screen many more, for much greater accuracy, New Scientist reports today.

Times Recommends

• Time-worn Freddie gives up Test matches
• Brighton company 'involved in cyber attack'
• The art of survival: it's all in the mind