Expression of retinoic acid receptors and dermal-epidermal interactions during mouse skin morphogenesis

The study explored the roles of the epidermis and dermis in skin morphogenesis, focusing on the communication between these tissues during the development of cutaneous appendages like scales, feathers, and hair. It was found that two waves of dermal information are crucial: an early wave for epidermal placode formation and a later wave for specific differentiation, such as choosing between scales and feathers or hair and glands. The research highlighted the impact of retinoic acid (RA) on embryonic skin morphogenesis, which could alter developmental pathways, such as inducing feather formation in normally scaled areas of chick embryos or gland development in mouse skin. These effects were observed when RA was applied at the placodal stage, suggesting it might modify the dermis to redirect placode development.