Gene expression pattern Interdigital apoptosis and downregulation of BAG-1 expression in mouse autopods

AbstractDigit formation during vertebrate limb development is a well-known example of programmed cell death. We have used this system toanalyze whether the formation of the interdigital necrotic zone in mouse autopods is linked with the expression of BAG-1, a gene with ananti-death activity. Here, we demonstrate that during development of mouse autopods, BAG-1 expression is downregulated upon theinitiation of interdigital apoptosis. We further show that retinoic acid induced interdigital apoptosis is also correlated with a downregulationof BAG-1 expression. On the contrary, the expression of BAG-1 remains unaltered in autopods of RARb 2/2 /RARg 2/2 mice which showsevere interdigital webbing due to a marked decrease in interdigital apoptosis. q 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: BAG-1L; Retinoic acid; Interdigital apoptosis; Syndactyly; Mouse development; Whole-mount in situ hybridization; Cochaperone; Bcl-2 associat-ing protein; Retinoic acid receptor; Digit formation; Nuclear receptors; Anti-apoptotic protein; Programmed cell death; Limb development; Interdigitalnecrotic zone; Autopods