Lupetti M, Dolfi A, Giannessi F, Michelucci S
Anat Anz. 1986;162(2):83-92.
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.
许多研究者已表明，鸡法氏囊淋巴滤泡的发育始于称为上皮芽的上皮芽体的形成。间充质干细胞迁移到这些上皮芽中，并产生滤泡髓质的淋巴细胞。然而，我们实验室使用半薄连续切片技术和电子显微镜进行的研究使我们认为，法氏囊淋巴滤泡发育的早期阶段可能以下列方式发生：干细胞迁移到衬里上皮的近端表面，在那里它们聚集在一个内陷处。这些细胞数量逐渐增加，形成一个细胞团，因此，这个细胞团不是在上皮框架内生长，而是在其下方生长。间充质团块附近的上皮内陷变得越来越明显，使上皮逐渐变薄，直到最终坏死。此时，间充质原基的细胞突入法氏囊腔。
