Histological examination of antler regeneration in red deer (Cervus elaphus)

Abstract

Annual antler renewal presents the only case of epimorphic regeneration (de novo formation of a lost appendage distal to the level of amputation) in mammals. Epimorphic regeneration is also referred to as a blastemabased process, as blastema formation at an initial stage is the prerequisite for this type of regeneration. Therefore, antler regeneration has been claimed to take place through initial blastema formation. However, this claim has never been confirmed experimentally. The present study set out to describe systematically the progression of antler regeneration in order to make a direct histological comparison with blastema formation. The results showed that wound healing over a pedicle stump was achieved by ingrowth of full-thickness pedicle skin and resulted in formation of a scar. The growth centers for the antler main beam and brow tine were formed independently at the posterior and anterior corners of the pedicle stump, respectively. The hyperplastic perichondrium surmounting each growth center was directly formed in situ by a single type of tissue: the thickening distal pedicle periosteum, which is the derivative of initial antlerogenic periosteum. Therefore, the cells residing in the pedicle periosteum can be called antler stem cells. Antler stem cells formed each growth center by initially forming bone through intramembranous ossification, then osseocartilage through transitional ossification, and finally cartilage through endochondral ossification. There was an overlap between the establishment of antler growth centers and the completion of wound healing over the pedicle stump. Overall, our results demonstrate that antler regeneration is achieved through general wound healing-and stem cell-based process, rather than through initial blastema formation. Pedicle periosteal cells directly give rise to antlers. Histogenesis of antler regeneration may recapitulate the process of initial antler generation.

Expression of VEGF and pleiotrophin in deer antler

“…Tissue growth is principally from the region of the reserve mesenchyme via the proliferation of stem cells, which then extend the dermis and the reserve mesenchyme distally (Li et al, 2005a). The proliferating cells are incorporated into the precartilage region (Fig.…”

“…1). Antlerogenic stem cells have been found to be concentrated in the reserve mesenchyme underlying the dermis (Li et al, 2002(Li et al, , 2005a. Cells from the reserve mesenchyme divide and differentiate, thus contributing chondroblasts to the precartilage region, where progressive maturation occurs.…”

Calcium orthophosphates (CaPO 4 ): Occurrence and properties

“…Once they have achieved the proper dimensions, the velvet starts to dry out, cracks and breaks off, while the antler's bone dies. Therefore, fully developed antlers consist of dead bone only Kierdorf 2000, 2005;Pathak et al 2001;Yuxia et al 2002;Li et al 2005). However, the formation and mineralization process of antlers is still not fully understood.…”

Antler velvet is thicker in adult than in yearling pampas deer (Ozotoceros bezoarticus): a histological study

“…Moreover, AV is a main product of deer farms which is used as a general health benefit: for example in Australia it is considered a food supplement, and in Asia it is a fundamental component of Traditional Chinese Medicine [5,30]. Li and Suttie [15] described the histology of the pedicle skin formation and its transformation to AV. Surprisingly, although there are several studies regarding velvet constituents [1,16,23,24, 34], we could not find any detailed histological characterisation of the AV.…”