Fig. 5: Quantitative comparison of tissue dynamics in τ-ξ spacetime.

A (The black dots) Interspecies comparison of the destination of each cell at a common time \({\tau }={\psi }_{{{{{{\rm{X}}}}}}}^{-1}(53.6)\approx {\psi }_{{{{{{\rm{C}}}}}}}^{-1}(27.5)\); P-D coordinate (left) and A-P coordinate (right). The gray dots indicate the variability in cell destinations within the same species (chick), which was evaluated using the bootstrapped tissue deformation maps as a reference against the difference between species. B Results of applying true and pseudo chick limb deformation maps to prospective skeletal patterns at t_Chick = 21. When the developmental clocks are synchronized and the state in the ξ-space at the same common time (\({\tau }={{\tau }}_{1}={{\tau }}_{2}={\psi }_{{{{{{\rm{C}}}}}}}^{-1}(27.5)\approx {\psi }_{{{{{{\rm{X}}}}}}}^{-1}(53.6)\)) is swapped between chick and Xenopus, the mapped skeletal patterns were very well matched, indicating that the rescaled tissue dynamics are conserved across species. In contrast, when the developmental clocks are out of synchronization, or the rescaled cell positions in Xenopus dynamics at a different time point (\({\tau }={{\tau }}_{1}\ne {{\tau }}_{2}\)) are used to calculate the pseudo chick map, both mapped cartilage patterns are significantly different (see also Supplementary Fig. 6). C Comparison of the rescaled tissue dynamics within different regions of the limb buds between Xenopus and chick. The consistency of the rescaled dynamics between species holds only for anatomically corresponding regions (green region; see the text and Methods for details). Source data are provided as a Source Data file.