NEUROD1 and hydrops fetalis: To test whether HF feeding induced EEC apoptosis, we used an in vivo apoptosis assay in which Tg(ubb:sec5A-tdTomato) zebrafish (Espenschied et al., 2019) were crossed with TgBAC(neurod1:EGFP) allowing us to determine if apoptosis occurred in EECs (Figure 4—figure supplement 3A–B).