The migratory pathway of neural crest cells into the skin of mouse embryos

Abstract

The migration of neural crest derived melanoblasts into the skin of mice was studied by the ectoderm-mesoderm recombination technique. Dorsolateral skin from albino and black mouse embryos at the time of initial melanoblast invasion was separated into ectoderm and mesoderm components, recombined with each other, and grown in the chick embryo coelom for a sufficient period to allow melanin formation. Recombined skin from embryos 11 days old formed pigment only when the mesodermal component was from a genetically black embryo. The black ectoderm-albino mesoderm recombinations failed to produce pigment in all cases. At this critical age when melanoblasts were first entering the skin, they were present exclusively in the mesodermal component. Skin recombinations made from 12-day mouse embryos showed a spread of melanoblasts into the ectodermal component, and by 13 and 14 days both dermal mesoderm and epidermal ectoderm were populated by melanoblasts.