Loss of ddx39ab leads to an embryonic lethal phenotype in zebrafish. (A) GFP expression pattern in zebrafish trapping line RP-011. Lateral views. S, somite. Arrowhead in inset indicates GFP expression in heart. (B) Morphological defects in RP-011 homozygous mutant embryos. RP-011 homozygous embryos did not show any morphological defects until 24 hpf; at 48 hpf, they showed a curved body axis, and at 72 hpf heart edema, dysmorphic jaw and widespread degeneration. At least 80 embryos of each genotype were observed and representative samples are shown. (C) The zebrafish ddx39ab genomic locus. Exons (blue boxes) are numbered. The transposon is inserted after the second intron. (D) Zebrafish Ddx39ab protein contains DEXDc and HELICc domains. Insertion of the gene-trapping element results in a fusion transcript that will be translated into a fusion protein containing the first 69 amino acids from Ddx39ab at the N-terminus. (E) RT-PCR results showing the presence of fusion transcript in RP-011 embryos. (F) qPCR results showing the absence of ddx39ab mRNA in RP-011 homozygous embryos. Data are mean±s.e.m. **P<0.01. n.s, not significant. (G) Injection of ddx39ab mRNA rescues the developmental defects of RP-011 homozygous embryos. (H) Quantification of the rescue of morphological defects of homozygous ddx39ab mutant embryos (Control) by injection of ddx39ab mRNA.
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