Treatment of zebrafish embryos with DAPT causes curved tails. A. A stock of DAPT or cpd E in DMSO was diluted in embryo medium, and increasing concentrations of DAPT or cpd E were applied to de-chorionated zebrafish embryos incubated at 28°C from 24 hpf to 48 hpf. Control embryos were mock-treated with embryo medium containing the same concentration of DMSO. Treatment of zebrafish embryos with 50 μM DAPT caused curved trunk and tails. B. DAPT- or cpd E-treated embryos were kept until 4 dpf, and images were acquired at 40 × magnification.