Bangyuan Wu; Zhengqiang Yu; Jiajia Deng; Shibin Yuan & Xi Peng

This study aimed to investigate the microstructure and ultrastructure of the Bursa cloacalis (Bursa of Fabricius) (BC) in young Leiothrix lutea at various days of age (a few days after hatching) using light microscopy and transmission electron microscopy. The bird BC was sampled at 1, 5, 7, and 9 days of age. Immediately after dissection, the structure and integrity of the BC (not degenerative) were retained and the specific temporal features could be visualized precisely. After hematoxylin-eosin staining and uranyl acetate/lead citrate staining, the microstructure and ultrastructure of the BC, respectively, could be observed clearly. The microscopic observations revealed the following: in addition to change in the size of BC or lymphoid follicles, many cavities were found in the BC; the distribution of the lymphoid follicles in Leiothrix lutea was different from that in other birds; and the segregating line between the bursal cortex and medulla became increasingly clear as the age increased. In conclusion, the structural data obtained in this study provides a better understanding of the specific immunological function of the BC in Leiothrix lutea.

KEY WORDS: Leiothrix lutea; Bursa cloacalis; Bursa of Fabricius; Microstructure; Ultrastructure; Lymphoid follicles

WU, B.; YU, Z.; DENG, J.; YUAN, S. & PENG, XI. Histomorphological structure of the Bursa cloacalis (Bursa of Fabricius) in young Leiothrix lutea: a comparative study using light microscopy and transmission electron microscopy. Int. J. Morphol., 39(6):1646-1654, 2021.