Dorsoventral-mediated Shh induction is required for axolotl limb regeneration (opens in new tab)

Axolotls (Ambystoma mexicanum) exhibit a remarkable ability to regenerate limbs. Classical experiments have suggested that contact between cells derived from distinct orientations—dorsal, ventral, anterior, and posterior—within the regenerating blastema is necessary for accurate limb pattern formation. However, the molecular basis for this requirement has remained largely unknown. Here, we demonstrate that both dorsal and ventral tissues are required for limb formation via induction of Shh ex...