Development of the spot pattern in the leopard frog

Abstract

Abstract Expression of the spot pattern on the dorsal surface of metamorphosing froglets of Rana pipiens seems to be determined by the dorsal integument rather than by the neural crest. At the neurula stage, dorsal ectoderm appears to be loosely determined with respect to pigmentary pattern. Results of skin rotation experiments suggest that by early larval stages the prospective dorsal spot pattern is precisely fixed in the integument.