Fig. 8.

Morphogenetic simulation reveals that globally oriented local tissue stretching, not spatially biased volumetric growth, is the major determinant of directional limb bud elongation and limb-specific shaping. In each panel (A-D), the top subpanels show the morphological change in a wild-type (WT) limb bud over 24 h. The middle subpanels show the morphological change in the limb bud of virtual mutant I [vMT(i)], in which the growth pattern is the same as in WT, but where the deformation anisotropy is low across the whole limb bud. The bottom subpanels show the limb bud of virtual mutant II [vMT(ii)], which has a pattern of anisotropy similar to that of WT but no spatially biased growth. Scale bars: 1000 µm.