Figure 1. Notochord vacuoles form through biosynthesis via rab32a and the HOPS complex. (A) 24 h post fertilization (hpf) zebrafish embryo expressing membrane GFP in the notochord. Anterior is left, posterior is right, dorsal is top, and ventral is down. (B) Higher magnification of membrane GFP in the notochord. (C) Cartoon depicting notochord structure of inner vacuolated cells surrounded by an epithelial-like sheath of cells. (D) Cartoon depicting trafficking requirements of vacuole inflation. EE = early endosome, LE = late endosome, lys = lysosome, SE = sorting endosome, VE = vacuolar endosome. Presumptive channels are found on the vacuole membrane. Scale bars: (A) 500 µm. (B) 50 µm. All panels adapted from Ellis et al. JCB 2013.