A messenger molecule was recently discovered that can turn mice's skin cells into hair follicles. Very hairy rodents have been created by researchers who induced follicle formation in mature skin cells, an event that usually only happens in embryos. Their findings, reported in the journal Cell, indicate that a molecule called beta-catenin may be a key message that tells cells in the embryo to become hair follicles, suggesting treatments for premature baldness and even applications in agriculture, such as sheep genetically altered to grow dense wool.

Prof Elaine Fuchs, who led the research team at the Howard Hughes Institute at the University of Chicago, said: "This is exciting because current treatments for baldness only work if there are living follicles left, or if the patient undergoes hair transplant surgery. Our research shows that new follicles can be created from adult skin cells if certain molecular players are induced to act."

One member of the team, Dr Uri Gat, said that the find was exciting because hair development in mouse and man is very similar. However, he said that although this is the first time follicle growth has been triggered in a live animal, a great deal more research must be done before it can be turned into a treatment. He said: "This is a very first insight into hair development, the first step towards - perhaps - clinical application. However, when you understand the process, you may indeed regulate it."

One problem is that the genetically engineered skin of some transgenic mice in this study made an endless supply of beta-catenin and benign follicle tumors formed. As well as switching on beta-catenin production, we need to know how to switch off the production once the hair follicle has been formed. Otherwise hair follicles may mutate under the influence of too much beta-catenin. Clearly beta-catenin is no the only promoter of hair follicle induction, it must work in combination with many other chemicals to form an adult hair follicle. Research must be done to understand how beta-catenin works and interacts with other chemicals.