Abstract
The bursa of Fabricius (BF) is a lymphoepithelial organ found only in birds. Differences in morphology of BF could play an important role in immune response. The objective of this study was to investigate the histological and histochemical characteristics of the bursa of Fabricius in the long-legged buzzard (Buteo rufinus). The material for the study comprised bursa samples obtained from three long-legged buzzards with permission of the General Directorate of Nature Protection and National Parks (Ankara, Turkey). Briefly, interfollicular epithelium (IFE) was shown to be columnar in shape and not to contain goblet cells. Reticular fibers were located in interfollicular septae. Each lymphoid follicle in the bursa of Fabricius in the long-legged buzzard was remarkably linked to the follicle associated epithelium (FAE). Namely, FAE has been reported to stimulate antibody production by transferring antigens to the medulla and have a leading role in developing of local immune response. Among the others, the species-specific differences in bursa of Fabricius morphology of long-legged buzzard (Buteo rufinus) also might support the continuity of this species in nature.