A Gharzi,
Volume 15, Issue 1 (4-2015)
Abstract
Formation of feather and hair follicles during embryonic stage is nearly similar but whether they possess a similar structure and organization in mature stage as well? The aim of the present research is to study similarities and differences of these two follicles in adult rats and pigeons. To fulfill this task, after removing follicles from the skin, the follicles processed for light and transmission electron microscopy. The results provided here demonstrated that these two follicle types are similar in having the dermal papilla, epidermal matrix and epidermal stem cells. Moreover, the production of hair and feather fibers in them is almost the same. One of differences seen between these follicle is that, unlike the hair follicle in the feather follicle a distinct compartment, called the pulp, is observed at the top of the dermal papilla. At the center of this pulp as well as the dermal papilla a blood vessel exists, a character which never seen in the hair follicle. Another difference observed is related to the thickness of the basement membrane exists at the interface between the papilla and epidermal matrix. This membrane in feather follicle is much thicker than its hair counterpart. In addition, at the basal region of the feather follicle there is a distinct population of stem-like cells which could not be distinguished in the hair follicle. Based on results provided here it seems that the feather in birds and the hair in mammals have been adapted for different biological tasks.
