Ultrastructural features of chick embryo skin cultured in a chemically defined medium

Abstract

Explants of 6 day chick embryo skin, cultivated in a chemically defined medium (Waymouth Medium MB 752/1) for 1 to 8 days wre fixed and processed for electron microscopic study. Excellent development and differentiation of chick embryo skin was recorded. The skin cultivated in vitro matured much earlier than in ovo. After one day in vitro the morphology of the skin is similar in the stage of development to that of a 10-12 day embryo skin in ovo. After 2 or 4 days in culture, the skins are comparable to those of 12-14 day or 15-16 day in ovo embryos, respectively. The periderm of the epidermis was highly developed andcontained a large number of peridermal granules after 6 days of culture. The skin proper, contained a granular layer, which resembled the skin of a 17 day embryo. Complete cornification of the epidermis was observed for the first time in vitro after 8 days of incubation. Keratohyalin granules which were claimed to be absent in avian skin, were observed.