title: Comparative studies on the secondary lymphoid tissue areas in the chicken bursa of Fabricius and calf ileal Peyer's patch.
abstract: The chicken bursa of Fabricius and calf ileal Peyer's patch are thought to be the primary lymphoid organs of B cell development. In the bursa, the existence of secondary lymphoid tissue, called the diffusely infiltrated area, has been recognized. Recently, we have found the presence of a region of secondary lymphoid tissue in the ileal Peyer's patch at the period of the most rapid growth of this organ. In this study, we compared the development of these secondary lymphoid tissue regions in the bursa and ileal Peyer's patch histologically. Before hatching, lymphatic follicle formation occurred in the bursa, but not in the diffusely infiltrated area, where only a small number of lymphoid cells were found. However, during fetal calf development, lymphatic follicle formation occurred not only in the primary lymphoid organ but also in the secondary lymphoid tissue regions. Therefore, the prenatal development of the secondary lymphoid tissue regions of the bursa and ileal Peyer's patch were distinct. After hatching, formation of the germinal center, which contained many CD4+ cells, was observed in the diffusely infiltrated area of the bursa. After birth, many CD4+ cells and IgG mRNA expression were observed in the lymphatic follicle of the secondary lymphoid tissue regions in the ileal Peyer's patch, but rarely in the ileal Peyer's patch lymphatic follicles. The change of character of these secondary lymphoid tissue regions at the postnatal stage might be dependent on external antigens.
authors.affiliation: Department of Veterinary Anatomy, Faculty of Agriculture, University of Miyazaki, 1-1 Kibanadai-nishi, Miyazaki 889-2192, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Kozuka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nasu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Murakami
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yasuda
mesh_terms: D000818:Animals; D001483:Base Sequence; D002060:Bursa of Fabricius / Q000033:anatomy & histology* / Q000196:embryology / Q000254:growth & development / Q000276:immunology*; D002417:Cattle / Q000033:anatomy & histology* / Q000196:embryology / Q000254:growth & development / Q000276:immunology*; D002642:Chick Embryo; D002645:Chickens / Q000033:anatomy & histology* / Q000254:growth & development / Q000276:immunology*; D017931:DNA Primers / Q000235:genetics; D007074:Immunoglobulin G / Q000235:genetics; D008221:Lymphoid Tissue / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development / Q000276:immunology; D010581:Peyer's Patches / Q000033:anatomy & histology* / Q000196:embryology / Q000254:growth & development / Q000276:immunology*; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D007074:Immunoglobulin G