Development Chromatophore

cross-section of developing vertebrate trunk showing dorsolateral (red) , ventromedial (blue) routes of chromatoblast migration

during vertebrate embryonic development, chromatophores 1 of number of cell types generated in neural crest, paired strip of cells arising @ margins of neural tube. these cells have ability migrate long distances, allowing chromatophores populate many organs of body, including skin, eye, ear, , brain. fish melanophores , iridophores have been found contain smooth muscle regulatory proteins [calponin] , caldesmon. leaving neural crest in waves, chromatophores take either dorsolateral route through dermis, entering ectoderm through small holes in basal lamina, or ventromedial route between somites , neural tube. exception melanophores of retinal pigmented epithelium of eye. these not derived neural crest. instead, outpouching of neural tube generates optic cup, which, in turn, forms retina.

when , how multipotent chromatophore precursor cells (called chromatoblasts) develop daughter subtypes area of ongoing research. known in zebrafish embryos, example, 3 days after fertilization each of cell classes found in adult fish—melanophores, xanthophores , iridophores—are present. studies using mutant fish have demonstrated transcription factors such kit, sox10, , mitf important in controlling chromatophore differentiation. if these proteins defective, chromatophores may regionally or entirely absent, resulting in leucistic disorder.