Fig. 1

Wdr4 is expressed in and required for the developing brain.a Whole mount in situ hybridization (WMISH) revealed expression of wdr4 in anterior structures of the zebrafish embryo (arrow heads) including the developing brain. Tb tailbud stage; 8 ss 8 somite stage; hpf hours post fertilization. Scale bars: 200 µm. b Live images of 48 hpf zebrafish embryos, which were either non-injected (NI) or injected with one of the following MOs: splCTRL, splMO or a MO blocking translation of Wdr4 (Wdr4 ATG MO). Scale bar: 250 µm. c Scatter plot showing the incidence of microcephaly in zebrafish upon Wdr4 KD. Co-injection of capped RNA encoding zebrafish Wdr4 rescues head size, while the patient-resembling Wdr4 R84H does not. n = 3?9 experiments with 93?244 embryos in total. d Loss of Wdr4 results in zebrafish embryos with smaller eyes, which cannot be fully rescued by wdr4 R84H injection. n = 3?9 experiments with 93?244 embryos in total. e Reduced size of cartilage structures in the developing head as shown by Alcian blue staining. Graph shows measurement of the palatoquadrate (red bracket). Lower bar shows control. n = 16/15; ****p < 0.0001, Mann?Whitney test. f Images of the otoliths in the otic vesicle upon injection of splCTRL or Wdr4 splMO. Scale bar: 10 µm. g Knockdown of Wdr4 increases the percentage of embryos with fused otoliths. n = 3?9 experiments with 93?244 embryos in total. ****p < 0.0001. One-way ANOVA with Sidak?s multiple comparison test. h Loss of Wdr4 randomizes heart looping in 48 hpf zebrafish embryos. D, correct D-loop; N, no loop; L, inverse loop. n = 4 experiments with 63?94 embryos. ****p < 0.0001. Fisher?s exact test. Scale bar: 200 µm. i Pancreas placement is randomized upon Wdr4 KD. R, pancreas right from the midline (dotted line); L, pancreas left from midline. Arrows indicate insulin n = 4 experiments with 63?94 embryos in total. ****p < 0.0001. Fisher?s exact test. Scale bar: 200 µm. Red lines: median.