Fig. 1. Label-retaining cells in body column of hydra at different times of chase.

Hydra were pulsed with EdU for one week and then cultured without EdU for four weeks. At the end of pulse, the entire body column was labelled as expected. As chase progressed from one week to four weeks, the number of label-retaining cells decreased but at the end of four weeks, label-retaining cells were observed in the body column. Images of hypostome and foot at different times of chase are shown in supplementary material Fig. S2A,B. Scale bars: 50 µm.