Figure 1.

Ascidian development. (a) A fate map of the ascidian egg, showing the territories that generate epidermis (blue), muscle (pink), mesenchyme (red), endoderm (yellow), notochord (orange), and central nervous system and nerve cord (green). Most localized mRNAs are confined to the muscle territory, colored in pink [12]. (b) A diagram of a section through the anterior-posterior axis of a tailbud-stage embryo, showing the position of the larval tissues derived from the different territories in the fertilized egg. Colors are as in (a). (c) A young post-metamorphic adult.