A LIGHT-MICROSCOPIC STUDY OF PRIMARY ANTLER DEVELOPMENT IN FALLOW DEER (DAMA-DAMA)

The ossification process of primary antlers was studied in five fallow bucks aged about ten months. In the growing primary antler the follow ing tissue zones could be distinguished histologically in a disto-prox imal direction: a proliferative zone, a zone of cartilage maturation a nd hypertrophy, a zone of cartilage mineralization and degeneration, a zone of primary spongiosa and a zone of secondary spongiosa. Although the strict disto-proximal zonation of tissue changes typical for endo chondral ossification of somatic cartilage was not seen in primary ant ler formation, the histological and histochemical findings clearly dem onstrated that this process can be best described as a modified form o f endochondral ossification. Our study produced no evidence for a dire ct (metaplastic) conversion af cartilage into bone during primary antl er development. Generally, the histogenesis of primary antlers closely resembles the process of secondary antler growth as described by othe rs. Minor differences between the two processes can be ascribed to the fact that during secondary antler formation a much bigger structure h as to be built up in an even shorter time span than in the case of pri mary antler development and, therefore, the processes of cartilage for mation, cartilage destruction and bone remodelling interdigitate even more closely during subsequent antler growth, compared to that of prim ary antlers. Our study clearly revealed that the transition from pedic le to first antler growth in fallow deer cannot be defined as a change in the ossification pattern, as was previously assumed for cervids in general.