Fig. 4. Defects in CNS regeneration after Smed-roboA RNAi. (A-F) Anti-tubulin immunofluorescence in control (A,C,E) and SmedroboA RNAi (B,D,F) 16-day regenerates. Arrowheads in A and B delimit the anterior commissure. (C,D) Regenerated cephalic ganglia in control (C) and Smed-roboA RNAi (D) planarians; magenta lines mark the position of the VNCs in more-ventral sections (shown in E and F). (E) Control: normally regenerated VNC; arrowheads show regularly spaced lateral processes. (F) Smed-roboA RNAi: improperly regenerated VNC; lateral processes are disorganized; magenta arrows indicate curvature. (G-J) Anti-phosphotyrosine immunofluorescence (green) in 5-day (G,H) and 16-day (I,J) regenerates. Hoechst staining is shown in blue. (G,I) Controls: regenerated cephalic ganglia overlap the regenerated nerve cord (arrows). (H,J) Smed-roboA RNAi: regenerated cephalic ganglia are not connected properly to the truncated nerve cord (arrows). (A-F) Anterior to the top left. (G-J) Anterior to the left. Images are confocal projections. Scale bars: 100 µm. cg, cephalic ganglia; vnc, ventral nerve cords; ph, pharynx.