Fig. 1. fms is essential for development of xanthophores and adult melanophore stripes, but is not expressed by melanophores. (A) Wild-type (strain AB^UT) zebrafish exhibits several well-organized dark stripes that include melanophores with intervening light stripes that include xanthophores. (B) fms^blue mutant adult, as a representative of fms mutants, lacks xanthophores and exhibits a disorganized pattern of melanophores. (C,D) Details of wild-type and fms mutant adult pigment patterns. (C) In wild type, melanophores are abundant in dorsal and ventral melanophore stripes, and a lighter interstripe region contains numerous yellow-orange xanthophores (arrow). Horizontal line is the horizontal myoseptum. (D) In a fms^blue mutant, melanophores are reduced in number and fail to form normal stripes, and xanthophores are not present. The fish in C and D are illuminated so as to avoid reflections from iridophores throughout this region. (E) Detail of wild-type stripe margin in which melanosomes are contracted within melanophores, allowing a few xanthophores (arrows) to be discerned within the boundary of the dark melanophore stripe. Iridescent iridophores appear bluish in this image. (F,G) mRNA in situ hybridizations of zebrafish larvae during late stages of pigment pattern metamorphosis. (F) fms expression is not apparent in melanophores, but staining is observed in adjacent presumptive xanthophores (arrow). (G) In contrast, expression of the fms homologue, kit, is readily detected in melanophores (arrow). Scale bars: (A,B) 4 mm, (C,D) 60 µm, (E) 80 µm, (F,G) 120 µm.

Return to article