Antler development was inhibited or stimulated by cryosurgery to periosteum or skin in a central antlerogenic region respectively

Abstract

Antler development is triggered by interactions between antler stem cells resident in the antlerogenic periosteum (AP) and the niche cells in the upper portion of overlying skin mediated by diffusible molecules. These interactive cell populations are interposed by the lower portion of the skin and the subcutaneous loose connective tissue (SLCT). It is known that mechanical deletion of just the central AP (having an area equivalent to the size of a pedicle base) by cutting through the skin and SLCT effectively stimulates the marginal AP to initiate antler development. This study was designed to investigate whether the SLCT layer plays a role in antler development by acting as a physical barrier. The results showed that the marginal AP failed to give rise to an antler after the central AP was cryosurgically destroyed with the preservation of the collagen structure of the SLCT. Furthermore, antler development was significantly advanced when the collagen structures of the skin and SLCT layers were substantially attenuated by repeated sprays with liquid nitrogen while keeping the central AP intact. Therefore, we conclude that the interposing SLCT layer acts as a physical barrier between antler stem cells and the niche cell types, and that timing of antler development is primarily controlled by the permeability of the SLCT layer to the putative interactive diffusible molecules.