Fig. 2

Zebrafish muscle is less sensitive to EtOH administered later in development. (A) Quantification of the percent of imaged segments with fiber detachments per embryo. 2% EtOH treatment from 48 to 72 hpf caused significantly fewer segments with fiber detachments per embryo compared to EtOH treatment beginning at 24, 30, or 36 hpf. (B) Quantification of the percent of embryos at each of the four EtOH treatment time points that fell into each of the three phenotype bins. (C–N) Anterior left, dorsal top, side-mounted, 72 hpf embryos stained with phalloidin (white) to visualize actin. Embryos treated continuously with 2% EtOH from 24 hpf, 30 hpf, 36 hpf, or 48 hpf through 72 hpf showed a spectrum of muscle damage severity that was binned into one of three groups: None (0 segments per embryo with dystrophy), Mild (1–10 segments per embryo with dystrophy), or Severe (11+ segments per embryo with dystrophy). White boxes correspond to zoomed-in, numbered panels. (C–E1) Embryos continuously treated with 2% EtOH between 24 and 72 hpf showed no muscle damage (C–C1), mild damage (D–D1), or severe damage (E–E1). (F–H1) Embryos continuously treated with 2% EtOH between 30 and 72 hpf showed no muscle damage (F–F1), mild damage (G–G1), or severe damage (H–H1). (I–K1) Embryos continuously treated with 2% EtOH between 36 and 72 hpf showed no muscle damage (I–I1), mild damage (J–J1), or severe damage (K–K1). (L–M1) Embryos continuously treated with 2% EtOH between 48 and 72 hpf showed no muscle damage (L–L1) or mild damage (M–M1). (N–N1) Control embryo. Scale bars are 50 micrometers. “e” = embryo. Error bars are standard error of the mean. *** p < 0.001, **** p < 0.0001.