Comparison of the Development and Involution Periods of Bursa of Fabricius with Histological and Histochemical Methods

The aim of this study is to histologically and histochemically determine the developmental and involutional stages of bursa of Fabricius of henna partridge (Alectoris chukar). In the study, bursa of Fabricius of 12 3-month-old (6 males, 6 females), 12 6-month-old (6 males, 6 females) henna partridges purchased from a private farm were used. It was observed that bursa of Fabricius was surrounded by a connective tissue capsule and consisted of tunica serosa, tunica muscularis, and tunica mucosa layers from the outside to the inside. It was seen that the tunica muscularis consisted of outer longitudinal and inner circular smooth muscle fibers. It was observed that the tunica mucosa made plicae towards the lumen of the organ and consisted of 10-15 plicae. It was seen that lamina epithelialis and lymph follicles were present in each plica. It was determined that the lamina epithelialis consisted of two parts called FAE (Follicle-Associated Epithelium) and IFE (İnter Follicular Epithelium). It was noted that the lymph follicles contained cortex and medulla sections and were separated locally by capillaries together with cortical medullary boundry cells. In the Methyl Green-pyronin staining method, plasma cells were found in the bursa of Fabricius of the henna partridge, in the connective tissue surrounding the organ, around the blood vessels and inside the follicles. In AB pH=2.5 staining, AB-positive reaction was seen only in the apical part of the epithelial cells forming FAE and IFE in the pre- and post-involution period. In PAS staining, PAS-positive reaction was observed only in the apical part of the epithelial cells forming FAE and IFE in the pre- and post-involution period. In PAS/AB pH=2.5 combined staining method, AB-positive reaction was observed only in the apical part of epithelial cells in the pre- and post-involution period. As a result of this study, it was found that bursa of Fabricius of the henna partridge did not undergo any histochemical changes despite its histologically large differences after involution.