AN IN VITRO STUDY OF HAIR AND VIBRISSAE DEVELOPMENT IN EMBRYONIC MOUSE SKIN

[摘要] The development of hair and vibrissae follicles were studied by disrupting the epidermal-dermal associations of the snout and mid-dorsal skin of 11-15 day embryonic mice. Separated epidermis and dermis from these regions of embryonic mouse skin were recombined in homologous and heterologous associations. The recombinants were cultured in vitro and their developmental capabilities were examined. Homologous recombinants of epidermis and dermis from snout and mid-dorsal skin continued their type-specific development in culture. However, the row-like pattern of vibrissae follicles was not maintained in recombinants of epidermins and dermis from snout skin. Heterologous combinations of 11-13-day snout epidermis and 14-day mid-dorsal dermis interacted and follicles identifiable as vibrissal follicles were produced. On the other hand, 14-day mid-dorsal epidermis combined with 11-13-day snout dermis did not produce follicles, although both epidermis and dermis remained healthy. Another method was used to disrupt the epidermal-dermal association of embryonic snout skin. Embryonic snout skin was dissociated into single cells and the co-mingled epidermal and dermal cells were grafted to the chorioallantoic membrane of chick embryos. Skin reconstruction and follicle development took place in these grafts. The nature of epidermal-dermal interactions in embryonic mouse skin and the relation of these interactions to the development of hair and vibrissae are discussed.