Characterization of dse1. (A–C) HPTS tracer movement assay in torpedo-staged embryos. HPTS moved freely in WT embryos (A), but was restricted in dse1 embryos (B and C). (D–F) Classification of PD in dse1 embryos: simple (D), twinned (E), and branched Y-shaped (F). (G) Fractions of branched (X- and Y-shaped) and twinned PD (B/T) in dse1, WT, and ise1 and ise2. Data for branched and twinned PD in ise1 and ise2 were published previously (15). *P < 0.05 compared with WT.