Figure S1.

(A) Representative dorsal images of chd8^+/+ and chd8^sa19827/+ zebrafish larvae at 5 days post-fertilization (dpf). The yellow line shows how the head was measured. (B) Dot plot of the measured head size for each condition tested. Welch’s t test was conducted between pairs of conditions. (C) Representative lateral images of the mid- and posterior intestines of chd8^+/+, chd8^sa19827/+, and chd8^{sa19827/sa19827} zebrafish larvae at 5 dpf stained with anti-HuC/D monoclonal antibody to visualize the enteric post-mitotic neurons. (D) Dot plot of HuC/D-positive cells for each condition tested. A t test was conducted between pairs of conditions. (E) Representative images of intestinal cross sections of chd8^+/+ and chd8^sa19827/+ zebrafish larvae at 5 dpf that underwent immunostaining against HuC/D. The limit between the lumen and the epithelium and the border of the muscle layers are depicted by dashed lines. (F) Representative images of intestinal cross sections of chd8^+/+ and chd8^sa19827/+ adult zebrafish that underwent immunostaining against HuC/D. HuC/D-positive cells are shown by yellow arrows. (G) Schematic showing the four intestinal quadrants defined to quantify the HuC/D-positive cells. (G, H) Dot plot showing the number of HuC/D-positive cells in each of the four quadrants shown in (G), for each condition tested. A Kruskal–Wallis test was performed. (I) Representative lateral images of chd8^+/+ and chd8^sa19827/+ zebrafish larvae at 65 hpf. In situ hybridization was performed using a probe against phox2bb. The position of the front of migration is shown by a black arrow. (J) Histogram of the position of the front of migration of enteric NCCs at 55 hpf, using somites as morphological landmarks. Fisher’s exact test was conducted between pairs of conditions. (K) Histogram of the position of the front of migration of enteric NCCs at 60 hpf, using somites as morphological landmarks. Fisher’s exact test was conducted between pairs of conditions. (L) Histogram of the position of the front of migration of enteric NCCs at 65 hpf, using somites as morphological landmarks. Fisher’s exact test was conducted between pairs of conditions. (M) Representative lateral images of the intestine of Tg2(phox2bb:EGFP);chd8^+/+ and Tg2(phox2bb:EGFP);chd8^sa19827/+ zebrafish larvae at 4 dpf stained with anti-phospho-histone H3 (PH3) monoclonal antibody to visualize the proliferating cells. Double-positive phox2bb+/PH3+ cells are shown by white arrowheads. (N) Dot plot of the number of phox2bb-positive/PH3-positive cells for each condition tested. A Mann–Whitney test was conducted between pairs of conditions. lu, lumen; e, epithelium; ct, conjunctive tissue; m, muscle layers; and n, number of larvae or adult fish.