To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie 1 The zebrafish tailbud contains two independent populations of midline progenitor cells that maintain long-term germ layer plasticity and differentiate in response to local signaling cues R. H. Row, S. R. Tsotras, H. Goto, and B. L. Martin Development 2015. 143:244-254; doi: 10.1242/dev.129015 Download Original Video