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Hair Follicle DevelopmentAdvances in Stem Cell ResearchIn the very early development of the human embryo, there is no indication of anything resembling a hair follicle. Neither is there an indication of anything resembling bone, nerves, internal organs or skin. The only cells in the early human embryo are precursor cells—stem cells—that are nudged into becoming specialized bone, nerve, internal organ or skin cells by the action of genes and the growth-and-development molecules produced by genes. It may be surprising to learn that hair follicles have a developmental relationship with many others tissues, such as breast and prostate gland, but this shows the built-in potential of stem cells to grow into a variety of specialized forms. Hair follicles do not just spring into existence from embryo stem cells. The path of hair follicle development begins in a group of stem cells that are nudged into different directions to become specialized cells of many different tissues and organs, including hair follicles. It may be surprising to learn that hair follicles have a developmental relationship with many other tissues, but it is not surprising to see another example of the built-in potential of stem cells to grow into a variety of specialized forms. It has long been known that hair follicle development begins in the very
early embryo, before the embryo begins to mature into the recognizably human
form of a fetus. There is an exchange of molecular “signals” between the outer
(epidermal) and underlying (mesenchymal) layers of cells that causes t |
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