Generation of crystal, a fully transparent combinatorial pigmentation mutant.
(a) Left: schematic diagram of the main populations of pigment cells in wild type (WT) zebrafish. Centre: cell lineages generating the different populations of pigment cells. Right: mutations affecting genes controlling either pigment cell formation (nacrew2/w2 and roya9/a9) or melanin production (albb4/b4) used to generate the crystal mutant. RPE, retinal pigment epithelium. (b-d) Pigmentation phenotypes of wild type, single mutant, casper and crystal zebrafish at adult (>3 month old, (b)), embryonic (3 dpf, (c)) and larval (7 dpf, (d)) stages. Red dashed boxes indicate crystal mutants. Insets on the right display eye pigmentation phenotypes. 3 dpf and 7 dpf zebrafish treated with 200 µM PTU are shown at the bottom of (c,d). Note that the optical transparency of crystal fish is higher than that of wild type, single mutant, casper and PTU-treated fish.