Q: What is the major obstacle to hair cloning?
A: Although many problems remain, the main one is to keep cloned cells differentiated (the ability to perform a specialized function, like producing a hair). There are certain cells in the skin, called fibroblasts, which reside around the base of the hair follicle. These cells are readily multiplied in a Petri dish. When these cells are injected into the skin, they have the ability to induce a hair to form (they are differentiated). The problem is that when these cells are multiplied in culture, they tend to lose this ability (they become undifferentiated).
A number of methods are being examined to keep these cells differentiated. Among them is the insertion of new genes into the cell’s nucleus to alter the expression of the existing genes. Another method is to change the spatial relationship of multiplying cells. The idea behind the second technique is that all embryonic cells have the same basic genetic material, but grow to have different functions (i.e., grow to form muscle, bone or nerves). One reason is that that the cells have a different physical relationship to one another and thus send different signals to each other based on this relationship. For example, the cells on the outside of a growing ball of cells may act differently than the cells on the inside, etc. If researchers can influence the way cells orient themselves as they multiply in the lab, this may enable them to become differentiated to produce hair and stay that way as the multiplication process continues.Posted by