Migratory patterns of cloned neural crest melanocytes injected into host chicken embryos.

Cloned quail melanocytes grown in tissue culture for 8 days or more were injected into 2 1/2-day-old chicken embryos. The pigment cells were placed directly into the somitic lumen by means of an injection micropipette. This technique for introducing marked neural crest cells into host embryos causes far less damage than previous methods which require extirpation and replacement of the neural tube. In addition, small numbers of homogeneous cells can be implanted by this procedure. When injected into one of the posterior somites, cultured pigment cells migrated along the ventral neural crest pathway. Three days after injection the melanocytes had migrated ventral to the dorsal root ganglia and prevertebral and primary sympathetic chain ganglia and were seen associated with the adrenal gland and aortic plexi. Melanocytes were frequently found in or adjacent to the gonads and often had migrated as far as the gut.