More than a century ago, Thomas Hunt Morgan attempted to explain the extraordinary regenerative ability of planarians such as Dugesia japonica, which can regenerate a complete individual even from a tail fragment, by proposing that two opposing morphogenetic gradients along the anterior–posterior axis are required for regeneration; here ERK and β-catenin signalling are shown to form these gradients.
- Yoshihiko Umesono
- Junichi Tasaki
- Kiyokazu Agata
