A Morphological Study of“Microfold” Cells of Lymphoid Aggregative Tissue in the Small Intestine of the Chicken
The morphology of lymphoid aggregative tissue of the small intestine was studied in the Japanese bantam chicken. Lymphoid aggregative tissue were composed of leaf-like villi unlike those in mammals. In the present study, these lymphoid aggregative tissues histologically were identified as Peyer's patches. Light and electron microscopy of the covering epithelium of the Peyer's patches showed that the cells had morphologically the same features of “Microfold" (“M") cells previously described in mammalian species. The authors demonstrated that the “M" cells of birds were not limited to the bursa of Fabricius, but also existed in the covering epithelium of the Peyer's patches in the small intestine. The proportion of “M" cells enfolding lymphoid cells much in mature chickens (18%) than in mature rats (100%).