Prostaglandin-b1, Embryonic Skin, and the Dermo-epidermal Junction

In previous studies, prostaglandins have been applied to organ cultures of dorsal skin from the chick embryo (11, 12) . When prostaglandin-B, (PGB,) is added to the culture medium in which skin pieces are explanted at a time when feather organ loci are present, the latter fail to develop during incubation but the skin continues to grow and mature . Control skins demonstrate normal feather development during 5-6 days of incubation . We are continuing the effort to explain this effect, especially through examination of the tissues by electron microscopy . In the course of these studies we have observed an unusual defect in the dermo-epidermal junction . Throughout the entire PGB,-treated skin there are numerous areas in which the dermo-epidermal junction is discontinuous . This effect is attributed directly to treatment of the tissue with PGB, . It is repeatable and has been found as early as the second day of incubation of the cultured skin . In some cases these areas of disjunction can be followed by serial section and are seen to lead into complete perforations of the epidermis, through which mesenchymal cells migrate or proliferate and coat the free surface layer (Fig . 1) . MATERIALS AND METHODS