Retinoid receptors in vertebrate limb development.

Although the precise role of retinoids in limb development remains obscure, the finding that retinoic acid can produce major alterations in limb patterning suggests that this ligand might be involved in the process of limb morphogenesis. Here we describe the patterns of expression of retinoic acid receptors and cytosolic retinoid binding proteins during the course of limb morphogenesis. Examining the distribution of these molecules in the limb and correlating their presence with important processes in limb development could help elucidate their possible functions.