RESUMO
It has been shown previously that erythroblast antigen (AG-EB) is an interspecies antigen expressed on the surface of nucleated red cells and reticulocytes. We have recently produced the monoclonal antibody MAE 15 that reacted specifically with murine epitope of AG-EB. Using MAE15 and immunocytochemical techniques on the light and electron microscopic levels the expression of AG-EB was studied in mouse embryonal and adult tissues. In mouse embryos AG-EB was revealed in erythroid cells of the yolk sac, liver and spleen, in epithelial cells of the intestine, salivary and thyroid glands as well as in the skin. The adult pregnant mice displayed AG-EB in cells of the yolk sac, decidua and trophoblast. The normal adult mice definitely expressed AG-EB not only in nucleated erythroid cells of the bone marrow and spleen but also in cells of non-hemopoietic organs and tissues: in epithelium of intestine, some glands and tubules of the kidney and testis; in endothelium of blood brain capillaries; in cells of the glandular layer of the epidermis; in insertion disks of myofibrils. Our findings suggest a possible transport role of AG-EB in different "barrier" cells.
