Tunicates are the closest living relatives of the vertebrates. Many aspects of their lives and development are, however, poorly understood. It is generally thought that among ascidian tunicates such as Ciona, the superficially vertebrate-like central nervous system of the motile 'tadpole' larva degenerates and is completely replaced by an adult nervous system that develops from scratch. Here, state-of-the-art transgenesis and imaging techniques are used to show that this is not the case. There is continuity between the larval and adult nervous systems, with the adult nervous system developing from stem-cell-like ependymal cells found in the larva.
- Takeo Horie
- Ryoko Shinki
- Yasunori Sasakura
