Fig. 2. Chimeras reveal cell autonomous and non-autonomous roles for fms during adult stripe development. (A,B) Bright-field (A) and fluorescence (B) micrographs of early larva (72 h) showing donor wild-type (fms⁺ GFP⁺) xanthophores over the dorsal myotomes of a fms^- mutant host. (C,D) Wild-type fms^- chimeras reared to adult stages (n=20) develop well-formed (C) or partial (D) melanophore stripes when donor melanophores and xanthophores are present. (E,F) Detail of wild-type fms^- chimera showing organized stripes that include donor (fms⁺ GFP⁺) melanophores (large arrow) and xanthophores (small arrow), as well as host (fms^- GFP^-) melanophores (arrowhead). This is the same individual as in C; note the absence of GFP⁺ donor cells in other tissues, such as myotomes or epidermis. (G,H) Melanophore stripe morphology depends on the presence of donor wild-type pigment cells. Opposite sides of a single wild-type fms^- chimera are shown in which well-defined melanophore stripes are present on the side exhibiting donor melanophores and xanthophores (arrow, G) but not on the side lacking donor pigment cells (H). (I,J) fms^- wild-type chimeras reared to adult stages (n=15) developed wild-type stripes. Although donor fms^- cells contributed to epidermis, nerves, bone and other derivatives, only one chimera exhibited donor (fms^- GFP⁺) melanophores (arrow) and these were present within host melanophore stripes; donor xanthophores were not observed. Scale bars, (A,B) 30 µm, (E,F) 200 µm, (G,H) 250 µm, (I,J) 60 µm.