Role of neural crest in determining the numbers of pigment cells in the melanoid mutant ofAmbystoma mexicanum Shaw

✍ Scribed by Sawada, Soledad Rivera ;Dalton, H. Clark

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 426 KB
• Volume: 207
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402070211

✦ Synopsis

Abstract

Experiments are reported testing whether the primary control of chromatophore development under the influence of the melanoid gene (m) in the axolotl is exerted by factors intrinsic or extrinsic to the chromatoblasts of the neural crest. Melanoid animals differ from the wild type in having more melanophores, fewer xanthophores and no iridophores. The total number of chromatophores remains unchanged. This is interpreted as evidence of a common stem cell derivation of melanophores and xanthophores in the axolotl. Hanging drop explants of melanoid neural crest duplicate the skin chromatophore ratios. Chromatophore counts from epidermal vesicles consisting of neural crest and somatopleure in different genotypic combinations provide the ratios expected according to the genotype of the neural crest component. In reciprocal homotopic transplantations of neural crest between melanoid and wild type embryos, donor type pigment patterns develop. These studies show that the effect of gene m is mediated by factors intrinsic to the neural crest cells prior to their migration.