Dose-response effect of GAT1033 on the curvature of the tail. Incubation concentrations were 0–300 µM for 72 h (illustrated with the brown triangle). The picture at the bottom shows a non-treated embryo at the same developmental stage.

Differential distribution of GAT1033 in embryos with and without chorion. The microscopy images on the left show the eye and parts of the yolk of 24-hpf zebrafish embryos. The intrinsic fluorescence of the compound was revealed using a laser scanning confocal microscope, after 18 h of incubation. The yolk (marked with *) shows a strong autofluorescence under these imaging conditions. The graph on the right shows the quantitation of fluorescence intensity (in arbitrary units AU) in treated embryos with and without chorion.

Characteristic morphology of caffeine treatment on zebrafish embryo at 2.4 mM. The tail of the zebrafish embryo treated with caffeine is like a pig tail.