Figure 1

Modulation of periodicity along the proximodistal axis of the handplate. (a) Schematic of an embryonic Gli3 null limb showing a polydactylous array of digits fanned across the handplate. Proximal to left, distal to right. (b) Proximal (red) and distal (green) regions of the striped pattern along the anterioposterior axis of the handplate at the positions marked by boxes in (a) illustrate that to maintain the number of digits along the proximodistal axis of the handplate, periodicity must scale with proximodistal position (λ2 > λ1).