Quail as the chimeric counterpart of the chicken: Morphology and ontogeny of the bursa of Fabricius

Abstract

The quail is the chimeric and parabiotic counterpart of the chicken, thus increasing the value of quail in the field of developmental biology. Quail bursa of Fabricius was studied by light microscopy, electron microscopy, and immunocytochemical methods. The basic cellular composition and structural framework are comparable with those of the chicken bursa. One of the major structural differences is the absence of the continuous cortico-medullary arch. In addition to the epithelial reticular cell the bursal secretory dendritic cell is the other medullary-specific bursal cell. The bursal secretory dendritic cell is a highly elongated cell which expresses vimentin intermediate filaments and produces secretory granules. The substance of the granules can be visualized by NIC2 monoclonal antibody, which was produced against guinea fowl bursal secretory dendritic cell. The released granular content appears on the lateral surface of the bursal secretory dendritic cell and is gradually solubilized. Thus, the NIC2-positive substance may occur in membrane-bound and solubilized forms in the isolated environment of the medulla. The bursal secretory dendritic cell establishes membrane contact areas with the B cells; therefore, they may influence B-cell maturation by cell contact and chemical (humoral) product. During embryogenesis bursal secretory dendritic cell precursors enter the epithelium and 1) induce epithelial bud formation, and 2) produce an NIC2-positive substance. Senescent bursal secretory dendritic cells can be phagocytic and migrate into the follicle-associated epithelium. This physiological turnover of the bursal secretory dendritic cell represents a novel pathway of macrophage formation from dendritic cells.

Locations of gut-associated lymphoid tissue in the 3-month-old chicken: a review

“…The lymphoid follicles that are not in contact with the bursal epithelium are completely encapsulated by connective tissue and contain a peripheral cortex that is separated from a central medulla by a capillary network and a basal membrane (Dasso et al, 2000;Nagy et al, 2001Nagy et al, , 2004. The cortex contains numerous densely packed B lymphocytes, along with some macrophages and cortical mesenchymal reticular cells (Nagy et al, 2004).…”

“…The cortex contains numerous densely packed B lymphocytes, along with some macrophages and cortical mesenchymal reticular cells (Nagy et al, 2004). In contrast, the medulla harbours a more heterogeneous cell population of B lymphocytes, macrophages, secretory dendritic cells and reticular epithelial cells (Nagy et al, 2004). The latter two cell types, however, regress immediately after hatching (Sanchez-Refusta et al, 1996;Nagy et al, 2001).…”

Impact of heterophil granulocyte depletion caused by 5-fluorouracil on infectious bursal disease virus infection in specific pathogen free chickens

“…In the medulla of the follicles, only the BSDCs may be charged with phagocytosis (Nagy et al ., 2004). In group 2, the BSDCs disappeared, as shown by a decreased number of vimentin-positive cells in the follicular medulla, substantiated by the faded IgG staining.…”

“…Under physiological conditions, the turnover of the BSDCs is slow. The senescent BSDCs enter the follicleassociated epithelium, and are eliminated in the lumen of the bursa (Nagy et al ., 2004). This turnover is highly facilitated by IBDV (Oláh et al ., 1997), and the BSDCs may leave the medulla not only towards the follicleassociated epithelium, but also through the corticomedullary border into the cortex, carrying the virus and the digested apoptotic cells.…”

“…This turnover is highly facilitated by IBDV (Oláh et al ., 1997), and the BSDCs may leave the medulla not only towards the follicleassociated epithelium, but also through the corticomedullary border into the cortex, carrying the virus and the digested apoptotic cells. Thus, the terminal maturation of the BSDC might be a phagocyte, distinct for the bursa of Fabricius (Nagy et al ., 2004). The multinucleated giant cells appeared first in the medulla and about 1 day later in the cortex.…”