Whole Mount In Situ Hybridization Protocol

Whole mount in situ hybridization and plastic sectioning were performed as previously described [18 (link)]. The antisense riboprobes were as follows: dct and mitfa of medaka [18 (link)] and sox10 of zebrafish [30 (link)]; and sox10a, sox10b and ltk were synthesized from the plasmid described above using SP6 polymerase (Promega) after restriction enzyme digestion: sox10a and sox10b; EcoRI, ltk; XhoI (NEB). For double fluorescent in situ hybridization, the probes were labeled with digoxigenin or fluorescein, and signals were detected with anti-DIG or anti-Fluor POD-conjugated antibodies with using Tyramide Signal Amplification system (Invitrogen). For sectioning, the stained samples were embedded in Technovit 8100 (Heraeus Kulzer) and sectioned at 10μm thickness. Images of stained embryos were taken using Leica MZ APO with attached AxioCam camera (Zeiss) or Zeiss AXIOImager.M2 with attached Orca-frash 4.0 camera. Images of sections were taken using Zeiss AxioPlan2 with an AxioCam camera. Confocal images were obtained with a Zeiss LSM880 laser-scanning confocal microscope.