Morphogenetic Mechanisms in the Cyclic Regeneration of Hair Follicles and Deer Antlers from Stem Cells

Figure 11

Differences between pedicle skin and antler velvet. (a) and (b) Pedicles and incipient generating (a) or regenerating (b) antler from a red deer. Note that comparing to pedicle skin (typical scalp skin), hairs of antler velvet are shorter, thinner, more sparsely populated, and growing out nearly at right angles to the skin surface. (c) and (d) Histological sections of pedicle skin (c) and antler velvet (d). Note that comparing to the pedicle skin, antler velvet has thickened epidermis (asterisk), large multilobed sebaceous glands (arrow), and neogenesis of HFs at different developmental stages (1, 2, 3, and 4) but has lost the arrector pili muscle and sweat glands.