Dynamic gene expression profiles during arm regeneration in the brittle star Amphiura filiformis

Echinoderms and in particular brittle stars display a remarkable ability to regenerate lost or damaged tissues. They offer an excellent model in which to study regeneration displaying extensive regenerative ability and close relationship to vertebrates providing the opportunity for comparative studies. Previous studies of gene expression during arm regeneration in brittle stars have focused on single genes commonly associated with the regenerative process. In this study we present the first microarray investigation of gene expression during arm regeneration in the brittle star Amphiura filiformis. We show the large-scale gene expression changes associated with the complex process of regeneration with over 50% of the clones measured showing a significant change at some point during the process when compared to non-regenerating arms. Particular attention is paid to genes associated with Hox gene expression regulation, neuronal development and the bone morphogenic protein BMP-1. Our data give an insight into the molecular control required during the various stages of regeneration from the stem cell rich blastema stage through to the highly differentiated regenerate. This work also forms an important basis for future gene expression investigations in this emerging model of limb regeneration.