Fig. S6

Knockdown of either mespa or mespb disrupted somite formation, but the expression of FoxD5 appeared unaffected. (L-F) Lateral views of trunk somites in wild-type embryos (WT) and embryos injected with different materials as indicated. Panels A′-F′ were magnified, and the somite morphology is shown in panels A-F, respectively. Zebrafish WT embryos exhibited normally developed somites at 18-hpf (A and A′). The mespa-MO- (B, B′) and mespb-MO-injected (C and C′) embryos displayed defects in somite formation. Injection of a control MO, mespa-5mis-MO, which contains 5-bp, which are mismatched to the corresponding mespa-MO, resulted in a normal phenotype (D and D′). When embryos were co-injected with either mespa-MO combined with p53-MO (E and E′) or mespb-MO combined with p53-MO (F and F′), the somite structure was still disorganized. Using whole-mount in situ hybridization to detect the expression of FoxD5 in WT (G), mespa (H), and mespb (I) morphants at 12-hpf as indicated. Like WT control embryos (G), the striped pattern of FoxD5 in the anterior PSM was clearly detected in both mespa (H) and mespb (I) morphants.