Determination of hair structure and shape.

The hair follicle attracted significant attention as a model for the investigation of diverse biological problems. Whereas its morphology and the structure of the hair shaft are known in detail, the molecular biology of this miniorgan is significantly less characterised. Many efforts focussed on the development of the hair follicle and its stem cell reservoir; by contrast, the follicular product, the hair, which is interesting not only in terms of cosmetics was neglected. This review highlights our current knowledge of the control of hair structure and shape with emphasis on mouse hair follicle biology and discusses continuing problems.