Chicken skin development is an excellent model to study the mechanisms of morphogenesis. It has a long experimental history and has been well characterized phenotypically. Chicken skin offers distinct patterns, large numbers of different cutaneous appendages, availability of in vitro culture systems, accessibility to microsurgeryin ovo, and the existence of skin mutants. All these factors make feather an ideal model for the investigation of epithelial-mesenchymal interactions and the regeneration of epithelial appendages (1 -3 ).
