P#43  Androgen Receptors are Expressed in the Developing Antler Tip and Velvet Skin of the Red Deer (Cervus elaphus)

N. J. Croft and V. A. Randall. Dept of Biomedical Sciences, University of Bradford, West Yorkshire, BD7 1DP, UK

Red deer (Cervus elaphus) antlers annually undergo rapid de novo development of new bone, skin and hair follicles in the spring. Antler development, and a mane on the neck in the winter season, are secondary sexual characteristics of red deer stags. Although androgens are involved, where they actually act in the antler is unclear. Therefore, we have explored the expression pattern of the androgen receptor in the developing region of antler tips in order to determine potential roles for androgens in antler velvet development. Androgen receptor transcripts were identified using RT-PCR. Positive control tissues, the prostate and testes, showed strong expression of this gene, while heart tissue did not express the androgen receptor gene. Androgen receptors were expressed in all regions of the developing antler tip, which includes the epidermis and dermis, reserve mesenchyme, and developing cartilaginous tissue. Results were confirmed in six different deer for the antler velvet epidermis and dermis; other tissues in at least two deer. In addition, expression was also identified in bald velvet showing only very early hair follicle bud developmental stages. Partial sequence of the androgen receptor in deer shows close similarity with the corresponding region of the bovine (Bos Taurus) gene. The findings in the developing antler tip suggest that the androgen receptor may play a key role in developing antler cartilaginous tissue. In addition, the androgen receptor may also have an exciting role in the developing epidermis and hair follicles of the antler velvet.