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Updated: Jun 2, 2026

Chicken Recombinant Limbs Assay to Understand Morphogenesis, Patterning, and Early Steps in Cell Differentiation
Published on: January 12, 2022
Regulative patterning in limb bud transplants is induced by distalizing activity of apical ectodermal ridge signals
Alberto Roselló-Díez1, Miguel Torres
1Departamento de Desarrollo y Reparación Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares, Instituto de Salud Carlos III, Melchor Fernández Almagro, Madrid, Spain.
Abstract:
We have used the chick limb as a model to gain insight into the longstanding question of regulative vs. mosaic development. To test the influence of signals on limb proximodistal development, distal limb bud tips of several stages were grafted to regions of the embryo known to provide different signaling environments. Of interest, thin grafts (100-micron thick) formed elements more proximal in character when grafted to the proximal limb region than when grafted to other regions. The extra elements were derived from host tissue, presumably distalized and recruited by the graft's apical ectodermal ridge signals. The results of classic and recent experiments have been reinterpreted in light of our conclusions.
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