Melanophore differentiation in the periodic albino mutant of Xenopus laevis.

That embryonic ventral truck tissue might play a role in expression of the periodic albino mutant phenotype (ap/ap) in Xenopus laevis was suggested from the experiments of MacMillan (1980). In contrast, the present experiments, involving the culture of isolated regions of Xenopus embryos, have demonstrated that both mutant and wild-type melanoblasts differentiate independently of a ventral trunk factor. A similar conclusion, that mutant melanoblasts differentiate independently of a ventral trunk factor, is derived from observations on neural crest cultures, wherein melanization of neural crest cells in both wild-type and mutant cultures occurred in a manner consistent with their genotype.