In　the　process　of　organogenesis,　different　cell　types　form　organized　tissues　and　tissues　are　integrated　into　an　organ.　Most　organs　form　in　the　developmental　stage,　but　new　organs　can　also　form　in　physiological　states　or　following　injuries　during　adulthood.　Feathers　are　a　good　model　to　study　post-natal　organogenesis　because　they　regenerate　episodically　under　physiological　conditions　and　in　response　to　injuries　such　as　plucking.　Epidermal　stem　cells　in　the　collar　can　respond　to　activation　signals.　Dermal　papilla　located　at　the　follicle　base　controls　the　regenerative　process.　Adhesion　molecules　(e.g.,　neural　cell　adhesion　molecule　(NCAM),　tenascin),　morphogens　(e.g.,　Wnt3a,　sprouty,　fibroblast　growth　factor　[FGF]10),　and　differentiation　markers　(e.g.,　keratins)　are　expressed　dynamically　in　initiation,　growth　and　resting　phases　of　the　feather　cycle.　Epidermal　cells　are　shaped　into　different　feather　morphologies　based　on　the　molecular　micro-environment　at　the　moment　of　morphogenesis.　Chicken　feather　variants　provide　a　rich　resource　for　us　to　identify　genetic　determinants　involved　in　feather　regeneration　and　morphogenesis.　An　example　of　using　genome-wide　single　nucleotide　polymorphism　(SNP)　analysis　to　identify　alpha　keratin　75　as　the　mutation　in　frizzled　chickens　is　demonstrated.　Due　to　its　accessibility　to　experimental　manipulation　and　observation,　results　of　regeneration　can　be　analyzed　in　a　comprehensive　way.　The　layout　of　time　dimension　along　the　distal　(formed　earlier)　to　proximal　(formed　later)　feather　axis　makes　the　morphological　analyses　easier.　Therefore　feather　regeneration　can　be　a　unique　model　for　understanding　organogenesis:　from　activation　of　stem　cells　under　various　physiological　conditions　to　serving　as　the　Rosetta　stone　for　deciphering　the　language　of　morphogenesis.　©　2013　Japanese　Society　of　Developmental　Biologists.