MBZ caused developmental toxicity in the zebrafish retina. (A) Zebrafish were treated with MBZ from 0 to 5 dpf at the indicated concentration. At 5 dpf, zebrafish were stained with ZMA462 and the retinas were imaged in vivo. The GCL, IPL, INL, and OPL are indicated by white arrows. The malformations in the IPL and OPL caused by MBZ are indicated by yellow and blue arrows, respectively. Scale bar: 50 μm. (B) Quantitative analysis of the developmental toxicity of MBZ in the zebrafish retina. The shape of the IPL in each zebrafish were quantified using the shape factor. n = 8 for control, n = 3 for each concentration, *p < 0.05 compared with control.

Development during 2 and 3 dpf was the critical window for developmental toxicity of MBZ in the zebrafish retina. (A) Zebrafish were treated with 0.3 μM MBZ during the indicated periods. At 6 dpf, zebrafish were stained with ZMA462 and the retinas were imaged in vivo. The malformations in the IPL caused by MBZ are indicated by yellow arrows. Scale bar: 50 μm. (B) Quantitative analysis of the developmental toxicity of 0.3 μM MBZ in the zebrafish retina. The shape of the IPL in each zebrafish was quantified using the shape factor. n = 5 for control, n = 6 for 1–4 dpf, n = 4 for 2–5 dpf and 3–6 dpf, *p < 0.05 compared with control.

Inhibition of ATM attenuated apoptosis induced by MBZ in the zebrafish retina. Zebrafish were exposed to 0.5 μM MBZ or 0.1% DMSO with or without 2 μM KU-55933 from 2 to 3 dpf. After exposure, zebrafish were subjected to TUNEL staining. The areas of apoptotic signal in the retina were measured and normalized by the area of retina. n = 8 per each group except for 0.1% DMSO and 2 μM KU-5593 (n = 5). *p < 0.05 compared with control. Scale bar: 50 μm.

ABZ and NCZ but not BBC caused developmental toxicity in the zebrafish retina.