Fig. S7.

Nerve cords break last. (A) Worm waist prefission; arrows indicate nerve cords at the edge of the worm. (Scale bar: 1 mm.) (B) Beginning of rupture; black arrows indicate nerve cords remaining on the edges of the worm. (C) After initial rupture in the center of the waist has almost completely nucleated outward; black arrows indicate that the nerve cords have not broken, and are some of the last tissue to break. (D) Worm has completely ruptured. (E) Full worm picture of antibody staining against synapsin showing two nerve cords that run along either side of the planarian. (Scale bar: 1 mm.) (F) Zoomed-in picture of E showing nerve cord width is roughly 50 µm. (Scale bar: 100 µm.)