Table 1.
Comparison of shh expression domains in equivalent axial structures of studied amniotes during notochord formation (HH/mammalian stage 5/6)
| Organizer level | Notochord level | ||||
|---|---|---|---|---|---|
| Posterior | Mid | Anterior | |||
| Rabbit | Dorsal | + (node-epibl) | − (floorpl) | − (floorpl) | − (floorpl) |
| Ventral | + (node-mes) | + (not) | + (not) | + (not/pm) | |
| Chick | Dorsal | + (node-epibl) | + (floorpl) | + (floorpl) | − (floorpl) |
| Ventral | − (node-mes) | − (not) | + (not) | + (not/pm) | |
Labeling: not notochord, pm prechordal mesoderm, mes mesoderm, epibl epiblast, floorpl floor plate