Dome epithelium and follicle‐associated basal lamina pores in the avian bursa of fabricius

Publisher Website
Google Scholar
Abstract
Background: The immunological role played by the avian bursa of Fabricius has been well established. Although numerous studies have also reported on the development and general morphology of this organ, some structure‐function relationships still hae not been fully explained. Methods. Bursae from chickens at three developmental stages were removed and examined by scanning electron micropscopy. Routine preparation was used as well as sonication (Microdissection). Micrographs were used for qualitative morphological study and for quantitative morphometric analyses. Results: Routine SEM observations were similar to those previously reported in the literature. Sonicated specimens allowed topographical study of various levels of surface erosion. Two types of surface cells were observed: typical absorptive epithelium and follicle‐associated epithelial (FAE) cells. Erosion of the dome surface epithelium revealed basal lamina pores n the region over the subepithelial lymphoid follicles. These pores were present at hatching. Morphometric analysis of dome and pore areas. Conclusions: Basal lamina pores may provide a communication route between the lympghoid follicles and the external environment via the FAE cells. Also, the close association between the FAE cells of the epithelial domes, the epithelial pores, the capillary complex of the previously described bursal‐blood barrier, and the subepithelial lymphoid follicles could represent a morphological “pure complex” that matures early in posthatching development and may be related to the immunological function of the bursa.