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

Figure 6

Tissue close association in organogenesis. (A) and (B) Reproduced with permission from [5, Figures 2G and 2M, resp.]. HFs in different developmental stages to show the close association between the mesenchyme-derived DP (d) and the epithelium-derived germ/matrix cells (A). Note that at stage 2 of HF formation, the hair peg is capped by DP cells (A), and at the bulbous peg stage, the DP cells are wrapped by HF matrix cells (B). (C) and (D) AUs in different developmental stages to show the close association between the AP-derived tissue (FL, fibrous layer of AP) and the overlying skin (De, skin dermis) prior to first antler initiation. Note that at the early pedicle stage, the two tissue types are separated by a very wide and loose layer of connective tissue (SLCT, (C)), but at the late pedicle stage, the two tissue types become closely associated (D). CL; cellular layer of AP.