Biomaterial Database

A contribution to the study of the histogenesis of the bursal lymphoid follicles in Gallus domesticus. 1986

M Lupetti, and A Dolfi, and F Giannessi, and S Michelucci

Numerous investigators have shown that the development of the bursal lymphoid follicle in chicken begins with the formation of epithelial gemmations called epithelial buds. The mesenchymal stem cells migrate into these epithelial buds and give rise to the lymphoid cells of the follicle medulla. However, research carried out in our laboratory, using the semi-thin serial section technique and the electron microscope, leads us to think that the early stages of the development of the bursal lymphoid follicle might take place in the following way: the stem cells migrate towards the proximal surface of the lining epithelium where they collect in an invagination. These cells gradually increase in number and a cellular mass is formed which, therefore, does not grow in the epithelial framework but under it. The epithelial invagination near the mesenchymal mass becomes more and more pronounced, making the epithelium progressively thinner until it is finally necrotized. At this point, the cells of the mesenchymal anlage protrude into the bursal lumen.

UI	MeSH Term	Description	Entries
D008221	Lymphoid Tissue	Specialized tissues that are components of the lymphatic system. They provide fixed locations within the body where a variety of LYMPHOCYTES can form, mature and multiply. The lymphoid tissues are connected by a network of LYMPHATIC VESSELS.	Lymphatic Tissue,Lymphatic Tissues,Lymphoid Tissues,Tissue, Lymphatic,Tissue, Lymphoid,Tissues, Lymphatic,Tissues, Lymphoid
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D002060	Bursa of Fabricius	An epithelial outgrowth of the cloaca in birds similar to the thymus in mammals. It atrophies within 6 months after birth and remains as a fibrous remnant in adult birds. It is composed of lymphoid tissue and prior to involution, is the site of B-lymphocyte maturation.	Fabricius Bursa
D002642	Chick Embryo	The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.	Embryo, Chick,Chick Embryos,Embryos, Chick
D005314	Embryonic and Fetal Development	Morphological and physiological development of EMBRYOS or FETUSES.	Embryo and Fetal Development,Prenatal Programming,Programming, Prenatal
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia