Figure 3

Figure 3

nnt mutants appear sensitized to ethanol teratogenesis from 6 to 24 hpf. Embryos were treated with 1% ethanol at different timepoints (A–H) to establish a critical period of ethanol teratogenesis. All images are ventral views with anterior to the left. Control (unexposed) wildtype and mutant (A, E) appear phenotypically normal. Wildtype embryos dosed across all timepoints (B–D) appear phenotypically normal. (F) Mutant embryos dosed at 6–24 hpf had stark craniofacial defects consisting of a hypoplastic Meckel’s cartilage (yellow arrow), deformed ceratohyal (red arrow), microphthalmia, and microcephaly. (G) Mutant embryos dosed at 24–48 hpf had no apparent defects in craniofacial morphology, but did have microcephaly and reductions in the size of skeletal elements. (H) Mutant embryos dosed at 48–72 hpf had no apparent defects. (I) Quantification of the percentage of fish with craniofacial defects in each group. (Fischer’s exact test, n ≥ 20 per group, **p  < 0.01, ****p  < .0001). The most highly statistical difference was observed at 6–24 hpf. Mut: mutant, Het: heterozygote, Wt: wildtype.