Fig. 1

Effect of aphidicolin treatment on radial nerve cord regeneration, day 16 post-injury. a The aphidicolin treatment significantly reduced (by a factor of two) the number of BrdU ⁺-cells in the regenerating RNC, but did not affect the cell density (b) in the rudiment, absolute cell number in the rudiment (c), nor the length of the regenerate. e and (f) show representative micrographs of the regenerating RNC in a control animal and in an animal injected with aphidicolin, respectively. The growing tip is on the right. These micrographs are merged images showing three different channels simultaneously: ERG1 (an antibody labeling echinoderm radial glia) in red, BrdU in green, and propidium iodide (PI) (nuclear stain) in blue. These channels are shown separately in Additional File 4. The dotted lines in (e) and (f) mark the area where cells were counted (the distal regenerate and 100 μm of the proximal stump tissue — see “Methods”)