Fig. 5

a, b A UCSC browser showing annotated snoRNAs (green) in the introns of nanog and dyskerin (dkc1). Ensembl annotated genes and snoRNAs are shown as black tracks. Teleost sequence conservation tracks are shown in magenta. Two snoRNAs selected for expression analysis are highlighted in oval. c–e In situ hybridization in whole mount zebrafish embryos at the 30% epiboly stage with probes detecting nuclei (c), snoRNA gene embedded in nanog (d) nanog coding exon (e), and overlay (f). ARrowheads indicate overlapping spots. g–j In situ hybridization with snoRNA probe (h) for the dyskerin gene is detected in the nucleoli of somitic nuclei detected by DAPI (g), and indicated by immunohistochemical detection of fibrallin (i and overlay in j). Arrows indicate the same spots in the overlapping frames. k–n In situ hybridization probes detect dyskerin and embedded snoRNA gene activities in long-pec stage embryos. k, m snoRNA probe detects expression in epiphysis (arrowhead with e), retinal ganglion cell layer (arrowhead with RGLC) and the somites (arrowhead in m). l, n Exon probe for dyskerin indicates cytoplasmic expression in the epiphysis (arrowhead and e), retinal ganglion cell layer (arrowhead RGCL), and retinal-pigmented epithelium (white arrowhead and RPE) and the somites (s, black arrowhead in n). Inserts in k and l show dorsal views of heads, from which the magnified views are cropped.