Fig. 5

Bilateral founder cells in the episphere. A The map of bilateral founder cells summarizes the position of all bilateral founders over time. The orange lines represent the division axis between the bilateral founder (colored spot) and its sister cell. The full lineage name is given for each bilateral founder. A’ The clonal offspring of the bilateral founders at 32 hpf, domains numbered according to panel A. The tracks with the same coloring is available in Additional files 4 and 7. B–E The first bilaterally symmetric divisions do not produce bilaterally symmetric clones. The offspring of the early bilaterally dividing cells at 6 hpf (B) and 8 hpf (C) was highlighted with different colors and their clonal domains were followed until 32 hpf (C’–C”’, D). Note the asymmetrical domains produced by the medial quadrant homologues 1m-11212 and 1m-11211 contrasting with the bilateral domains produced by the lateral quadrant homologues 1m-1122, and the medial region completely devoid of symmetrical clones. See Additional file 14: Figure S4 for more details