Behavior of ENCCs rostral to the wavefront. A, B. E12.5 proximal colon, approximately 1.1 mm behind the wavefront, red channel only. B. A total of 3.5 hours after photoconversion, many cells had migrated caudally (white arrows), and there was also some dispersal of cells rostrally for a short distance (yellow arrows). C, D. E12.5 mid-small intestine, red channel only. D. Although the cells were very dynamic, after seven hours, only a small number of cells (arrows) had migrated substantial distances longitudinally. E, F. E12.5 distal small intestine; three small groups of cells (seven cells in total) were photoconverted. F. Tracks of the seven cells showing that they migrated variable distances in variable directions. G, H. E11.5 gut. Individual cells (arrows) in a variety of locations were photoconverted (G). H. Tracks of photoconverted cells overlaid on red channel only. Most cells in the pre-cecal gut were migratory, but often in a circumferential direction (H). Pre-cecal ENCCs migrated slower (tracks are shorter) than post-cecal ENCCs. ENCCs, enteric neural crest-derived cells.