Fig. 2

Ability of human VANGL1 RNA variants to rescue the convergent extension defect in zebrafish embryos treated with tri-MO. Panels A–F show lateral views of zebrafish at approximately 2 days post fertilization. In Panel A, an uninjected wild-type fish is shown. In Panel B, a fish injected with tri-MO alone show a marked shortening of the trunk. In Panel C, VANGL1 RNA partially rescued the trunk phenotype induced by co-injection of tri-MO. VANGL1^M328T (Panel D) and VANGL1^V239I (Panel E) RNA injection failed to compensate for the phenotype induced by co-injection of tri-MO. In Panel F, VANGL1^R274Q RNA partially rescued the tri-MO induced phenotype. Panels G–L show 10–12 somites embryos, with the arrows pointing at the tip of the head and the end of the tail. The angle formed by the arrows and indicated by dotted lines was measured to assess the extension defects in zebrafish lacking tri. Injection of tri-MO (Panel H) caused a significant increase in body angle. This defect was partially rescued by co-injection of tri-MO with VANGL1 (Panel I) or VANGL^R274Q (Panel L). In contrast, tri-MO + VANGL1^M328T (Panel J) or tri-MO + VANGL1^V239I (Panel K) failed to induce a recovery in extension processes and caused the body angle to remain larger. Panels M–R show dorsal views of 8–14 somites zebrafish embryos stained with MyoD. In Panel M, the converged and extended somites of a wild-type embryo are shown. In Panel N, zebrafish injected with tri-MO alone exhibit wider somites lining the open neural tube. In Panel O, VANGL1 RNA co-injected with tri-MO rescues neural tube closure and convergent extension. However, VANGL1^M382T (Panel P) or VANGL1^V239I (Panel Q) RNA injection fail to rescue the tri phenotype while VANGL^R274Q RNA injection (Panel R) compensates for the phenotype.