Figure 3.

Lineage contributions to the larval CNS. (A) 8-cell stage embryo in lateral view (left) showing the four founder lineages, a4.2 (grey) and b4.2 (green) of the animal hemisphere and A4.1 (tan/yellow) and B4.1 (white) of the vegetal hemisphere. Middle shows a schematic drawing of the larval CNS with the contributions from the a4.2 (grey), b4.2 (green) and A4.1 (tan and yellow) shown and summarizing the main contributions from neural-epidermis precursors and neural-mesoderm precursors. Right is a cross-section though the tail showing the chordate organization of axial notochord (N, light blue), lateral muscles (M, dark blue) and the neural tube (NT, green, yellow and tan). For NT, contributions of founder lineages are indicated with colors whereas notochord derives from A-lineage (mostly) and B-lineage and muscle derives from B-(mostly), A- and b-lineage. ES-endoderm strand. (B) Schematic drawings of embryos in vegetal pole view and cell lineages of one A4.1 and one b4.2 showing the bi-fated neuromesoderm precursors in red. Other colors indicate fate-restricted lineages following the same color code as (A) The green dots indicate b-line CNS precursors, the fate segregation of which is not fully resolved.