Supplementary Figure 3: nterstripe formation precedes stripe formation and is necessary for subsequent stripe formation.
(a–c) At the onset of metamorphosis, clusters of iridophores appear along the horizontal myoseptum (arrowheads in b). While the clusters of iridophores form the first interstripe (X0 in c), melanophores (arrows in c) begin to appear in the skin. Stripe 1D and 1V become clear at later stages as more melanophores appear in the stripe region (e–f). (d–h) The initial fuzzy boundary between stripes and interstripe gets sharpened during metamorphosis. New interstripe (X1V) starts to appear at subsequent stages (40-50 dpf) and is prominent in (h-i) while dark stripe are yet to develop. Scale bar: 100 m. (j) Compared with wild-type controls, iridophore mutants add fewer stripes beyond the basic metamorphic stripes 1D and 1V. (k-l) In animals homozygous for a weak allele of rose (genotype: rosetAN17X;Tg(sox10 : ERT2 − Cre)/+;Tg(β − actin2 : loxP − STOP − loxP − DsRed − express)/+), iridophores appear scattered (arrowheads in c indicate a few scattered loose iridophores) and disorganized unlike the iridophores in the (b) control sibling. Arrow: a small cluster of iridophores in the interstripe X0.
