| Limb regeneration has been most intensively studied in the urodele amphibians, however, the refinement of the danio rerio, zebrafish, as a genetic system permits the study of the genetic control of development and regeneration on a much larger scale. In addition, the epimorphic regeneration process of the zebrafish fin is very similar to the regeneration process of the tetrapod limbs, with the advantage that the fin presents a relatively simple anatomy, and complete restoration of the regenerate within a few weeks.;Two specific aims have been studied. On a cellular level, in order to specify the origin of cells that contribute to the regenerate, we used the lipophilic carbocyanine dye, Di-I, to label and subsequently to characterize the epidermal and mesenchymal cell contributions from the stump tissue of the caudal fin to the regenerate.;On a molecular level, we investigated a method to introduce genes of interest into the regenerating caudal fin. By injecting Green Fluorescent Protein (GFP) reporter constructs into the blastema of regenerating caudal fins, we successfully transfected blastemal cells. Using this approach, we try to misexpress the sonic hedgehog gene in the regenerating fin in order to further investigate the function of this gene in the formation and patterning of the dermal bone of the fin. (Abstract shortened by UMI.). |
